Ah ha! I was looking for a low voltage thermostat with an adjustable differential to use with my pellet stove! Using a standard thermostat with a pellet stove results in it cycling on and off constantly-the typical thermostats usually have a 1 degree differential. The stoves take about 20 min to shutdown completely, and about 5-10 min to power up and start producing heat. For me, an 8-10 degree (F) differential is perfect! (As well as time delays) thanks for the video!
Must be something in the ether. Yesterday I dug out a single relay version of this style of device that has been lurking in my 'future projects' box for years, with the intention to make something with it, then that evening, I saw this video. Strange alignments!
I vote a sous vide controller. I made a simple 'inline' setup with an old extension lead and an enclosure. Slow cooker with the probe in it for the bath. Best steak I've ever eaten, from the cheapest cuts possible (right up your street!!)
@@joelaw728 yeah. Sous vide, or temperature control for cheese making, or for a cheese maturing fridge. There are a lot of applications for fine temperature control that I could make use of
I've been using STC-1000's for temperature control for my aquariums for years, with the oldest one being 6 years old. Simple, accurate, and cheap. The heat and cooling control is amazing. I have both heaters and chillers on my tanks and by using one controller, it eliminates the risk of having both the heaters and chiller on at the same time. Highly recommend them.
@@ALAPINO EcoPlus 1.5hp, and 2 aqua euro 1/10th hp. (Separate Tanks/systems). All the chillers and heaters have their own thermostats also, so I utilize those as a redundant cut off. For example, System temp is set to 78°, the STC is also set there with a 1° deviation. So the main (STC)temp range is 77-79°, therefore I have the chiller set to 76° and the heaters set to 80° on their built in thermostat. If the STC was to fail closed, the heater/chiller will shut itself off once it reached its own set point. This helps prevent them from getting stuck on and freezing or cooking the tank.
@@noahsheehan7824 Cheers! Thanks for the information! That's exactly why I'm leaning towards something like an STC, cost effective redundancy. My old home gets very cold in the winter and very hot in the summer. Not ideal for the animals we keep. :P
I'm using them for exactly the same function although I don't use the cooling function, just the heating side. I set the aquarium heater to a couple of degrees higher than optimum so that if this unit should fail in the 'on' position the thermostat within the heater will turn off before the water temperature gets too drastically high. I have had just about all types and makes of aquarium heaters and I have yet to find one that is reliable and keeps the same temperature, it seems that because most of them use a bimetal strip they will alter over time. The greatest advantage is that I can check the temperature of all my 6 tanks just by glancing at them from a distance, the majority of aquarium thermometers are a total pain to read.
I LOVE THE STC-1000! I have one I installed to control a deep freezer, and it has reliably served for at least 5 years now. Never an issue, perfect absolutely perfect little device.
I came across these PID controllers when I was upgrading/modding my Gaggia Classic Pro espresso machine. The normal bimetallic controller would control the boiler approximately within 10 degrees which if you're obsessed with espresso is no beuno. You can set the temp precisely on them and these little buggers will keep the boiler within a degree. I've also seen them being shoehorned into Rancillio Silvia machines.
I live in an RV (caravan) in Mesa, AZ where it can get to 120F (50C) in the summer. The back of the refrigerator is exposed to the outside and has a problem operating above 85F (30C) so I bought one of these to switch on a small fan at that temperature so that it blows on the refrigerator coils. This works pretty well up to an outside temperature of 105F (40C); after that, nothing will help and the temperature inside the refrigerator will go up to around 50F (10C). The refrigerator operates on 12v so I hooked it up to the 12v line coming into the back, and the device will work even when I'm on a trip and not connected to shore power. My project for this summer is to add a second fan that will blow cold air from inside the trailer into the area behind the refrigerator to increase the efficiency of the refrigerator on very hot days.
Seems about right for controlling a fridge full of Lager beer during fermentation! Also love the pro tip regarding relay failure that can be mitigated with a bimetallic switch and a neon bulb + resistor as failure indicator placed across the switch. Neat! Thanks for sharing!
These aren't the same units, but I learned not to trust the relays in these types of things after a PID controller running some simple resistive heating tape managed to fail after only a few months. The relay got stuck in some halfway-closed state and emitted a bunch of smoke. After that, I switched to having the relays in these switch a solid-state relay that would switch the real load. More expensive and less efficient due to the drop in the SSR, but never had problems after that.
There's a substantial difference between an ordinary relay and a contactor: the latter is built to handle much more current and is arc flash resistant. In resistive heating or other high-current applications, a contactor is usually the safest choice. SSRs are also good, but beware that SSRs can sometimes fail and when they do, they usually fail closed - meaning the circuit stays live.
@@petergamache5368 Hence, the need for a thermal fuse in heating applications. The actuating circuit can fail with contactor permanently activated. Belt and braces for safety is a good rule of thumb. In my lab application, the heater is only 75W.
I've been using one of these for ten years! We use it to drive a heating pad, so our parrots are nice and comfy during our chilly winter nights, and it's been absolutely reliable. Mind you the load switched is only 25W (so 100mA) resistive. Easy to set up, and easy to get parts for (important for when "they" chew through the NTC probe cable!)
I've used one to cool a fermenting beer, to 18°C in a 21°C room, it ran an aquarium pump that sat in a cooler filled with ice water, replaced ice as needed. It worked well for that at least, ran for about a week.
I used 3 of these (mains voltage type) to control three (Beko) domestic full-sized chest freezers, in order to maintain them in the range -25 to -18 degrees C. This was required to maintain chemical thermal blocks within a known temperature range prior to use in pharma shipping of cold chain products. They (and the freezers plugged into them) worked flawlessly over 3 years, at which time we left that business. Great to see the innards and learn of their circuitry, as always. Like you suggested, I always kept two units as spares (given the low cost) but they were never needed. I would happily use again, should the need arise.
I've had a 110v one in operation since 2016, It is used as a low temp cutoff for an array of server fans propped up in a window to cool off my room. it has switched up to 5 amps of 12v for years, but usually it's ran on a lower voltage unless its quite hot. they are great units for the price. at just $15 I've ended up with more of them now to just use as thermometers for various things. the relays are an added bonus at that point
I use one of these as a "freeze guard" on our central AC unit. I threw it in while I was waiting on some R22 a few years back but after I fixed the issue and recharged the system, I ended up leaving it on just as a failsafe. If my suction line gets below 5C, it cuts off the condenser and just lets the inside fan run by itself. Just set the cooling temp to 6C and a 1C swing. It's wired to always be on and only the condenser control line is switched thru it. I set the compressor delay to 10 minutes so if it *does* start to freeze, it'll kill the compressor for 10 minutes to let the evaporator thaw. I know 5C isn't freezing but if the suction is that low, icing has already started on the evaporator on the first few loops after the expansion point and once the first few turns start to freeze, the rest will ice pretty quick. Great video as always Clive!
My experience has shown these relays to be incredibly dangerous. They arc weld easily. I bought one with exposed PCB that runs on 12V and only one relay, but after a few months it wouldn't turn on the heater. I found a relay like it on Digikey, and replaced it with a real Omron for about $10. 3 Years so far an no worries.
Unfortunately, when last visiting the Omron website to get specs and catalogs, all I could find was marketing noise about products for hospitals etc. Seems a bad trend among corporate website designers to hide their signature products under mountains of aspirations to enter new markets.
@@Margarinetaylorgrease Without looking at a snapshot of a current probe, it's hard to say how huge the current to the motor at startup is. It's high enough that prevents most power inverters to shut down. If you have the experience, replace it with a known brand that matched that footprint. If you haven't done that before, don't start with this. Start with something less critical. Buy a better quality. Pay once, cry once.
This does look like a generic version of an inkbird temperature controller, which seems more robust from my experience while still being relatively inexpensive. I'd be interested in your take on an inkbird.
@Charles Lambert I've used one of these cheapies with a slow cooker for Sou Vide and also heating element for brewing and also with a freezer for lagering with great levels of success. They're not that bad.
I used one of these to convert my dad's old analog electric smoker for his birthday. It made the smoker maintain a much more precise temperature. I got one that had a 30A relay built in.
For those that miss an important point: Switch/Relay ratings printed on them is _near always_ Max Amps at VAC unless actually says VDC and all for purely Resistive Loads. Look up data sheets and you find the rating for Inductive at best is 1/3 to 1/2 of Amps for given Max Volts. Even parts made by Omron and other well known brands have same markings on them and will burn with Inductive Loads. Motors, fluorescent and other lights with a ballast, transformer and more will burn down any switch point fast because of this. But Some Datasheets don't bother listing this info and many people burn out the contacts and worse...
So-called "definite purpose contactors" are rated in amps for an inductive load. Therefore a 40-amp definite purpose contactor is rated for a 40 amp inductive load. They're primarily used in HVAC applications to switch motors and compressors, and may only be available in USA/Canada.
Yes, when I tried to design my own relay boards I found this to be buried deep, and often with no useful numbers for individual products. Also the published information on prolonging contact life with snubber networks falls into the useless category of "measure your very specific finished product and redesign circuit for that specific situation", which is highly impractical when trying to make something intended for 3rd party use with unknown loads. As a workaround (never built and tested), I considered using a MOV to eat the back EMF from inductive loads, thus preventing excessive contact wear.
@@brianleeper5737 The Contactors goes by different names but they do use versions world wide. These are not cheap or available to general public in normal retail. In the U.S. you are often looking at Graybar and other industrial suppliers to buy them and meet Electric Codes.
I looked but Can't find exact JQC-3FF above. Others start same and FL-3FF-S-H the datasheets have No mention of Inductive loads. Contrast to Songle SRD-05VDC-SL-C (Used by Elegoo and many other Arduino/Pi kit makers) Datasheet rates Type C contacts Resistive Load 7A 28VDC, 10A 125VAC, 7A 240VAC Inductive Load 3A 28VDC, 3A 120VAC If part number end with A means Type A contacts rated for Resistive Load 10A 28VDC, 10A 240VAC Inductive Load 5A 28VDC, 5A 120VAC Omron sheets are similar with reduce I-loads for most relays. Some Relays for Cars are made to handle 10 to 20 Amps at 20VDC because controls Fuel Pumps, AC Clutches, and more but they often wear out faster doing that vs Turning On Halogen Headlights pulling More amps then the motors/coils. Same problem at home with standard wall switches burning up every few years at best controlling garbage disposers, fluorescent lights, etc.
Clive, I have the Inkbird ITC-1000F in my house, its very similar to yours but its display will support Centigrade and Ferinheight. Here in the USA that helps. It functions a little differently than the SCT-1000 but is the same case and connections. I have hot air oil heat so I have mounted the thermocouple into my dryer vent that I change to vent into the basement through filters. When the dryer vent reaches 75 deg F it turns on the fan in my furnace and dissipates the heat throughout the house along with the humidity in which is greatly needed in the winter. Works great!
I have two similar 240v units mounted in a box by my bed. I have one temp sensor in the bed at foot level under the electric blanket. I set this at 30c. The other unit is wired in series, measuring the room temp, set at 24c. The electric blanket is set on #3 ( full heat). All this is powered by a clock timer to run between 10:30 pm and 7:30 am April to September. I was so sick of waking up shivering at 3am or covered in sweat if it was a warm night. So now I have the Goldilocks setting and it is just great. Its has been running for nearly ten years. Plugged in last week for the on coming winter.
I've been using these with my fermentation fridge for years with an incandescent light bulb, and for controlling a freezer as a keg fridge. I also use Inkbird 308s but the non. WiFi version has occasional temperature transients that cause the fridge to kick in for a brief time occasionally (it's a known bug they know about) and its cali bration can shift. I find cheap stcs more reliable than 308s.
I use an Inkbird in a gutted out mini fridge for starting plant seeds. It runs a 40watt incandescent for heat and a couple of 80mm fans for cooling. A Defiant timer switch controls CFL lights. Hole sawed a bunch of holes for fresh air.
I think a return visit is required Clive, the relays and their real-life current switching capacity and the loads they're capable of dealing with are where the rubber hits the road. A brief run through the comments here says there is a story to be told. Jumping into some of the datasheets for them is.... interesting!
I have a couple of these units here in Canada to control a freezer and fridge. So far they work great and yes I used an external relay for control. Love to fact that they readout actual temperature of your appliance. 👍
Same here. Absolutely amazing results. Made mine using a basic enclosure box and an old extension lead. That way I can stick the probe and meat in any slow cooker; future proof and didn't need to modify my slow cooker :)
@@joelaw728 Great minds think alike? I can use my little friend to control the temperature of many things. I also am building another to use with a small freezer for a cheese cave.
I have once repaired a very similiar thermostat that controlled a fridge. Due to moisture build up, a leakage current was flowing over the pcb from live to neutral. This resulted in a trace of carbon which was conducting enough to short the live to neutral with a loud bang. I had to cut a slot into the PCB in order to remove the carbon trace and to gain a better separation between live and neutral.
Hi mate. I used to work for a commercial cleaning equipment contractor. They supply a machine called a decarboniser. Using one of those to heat either 10,35,50 gallon water tanks using domestic elements used for central heating. It was a smaller part of their business but u used to replace approximately 5 of those controllers every week !!!
I have one of these units. I put my Ender3 in a 12-U enclosed/vented networking cabinet. The cabinet came with a pair of 120mm mains voltage fans. I routed the temperature probe wire through the cable chain onto the Z-Axis Rail so the probe is about 20mm above the print nozzle or the piece being printed. I have the temperature set to 37.7˚C (100˚F) with a 3˚C Differential. Compressor setting disabled and the fans connected to the cooling side. Nothing is connected to the heating side. This keeps the ambient temperature hot around the print but kicks the fans on if the temperature rises too much. I found it helps to prevent the print from warping and coming off the print surface during printing.
I have a few of these running, both mains and DC powered. One AC unit has been running for near 10 years controlling a cooling fan on my grid tie inverter system (non kosher). Another DC unit has been controlling via a power relay a cooling fan on my Land Rover diesel, Lucas electrics have not managed to destroy it in 12 months so they must be tough.
I had 2 of the real Elitech versions of these in my hombrew set-up 10+ years ago, installed in a jiffy box with IEC connectors for input, heating (during fermentation in winter) and cooling (during fermentation in summer and to turn a freezer into beer keg fridge). Passed it onto my mate as I have no time for homebrewing anymore, but it's still going strong!
been using these mains cheapies for heating/cooling various greenhouse and seedling tents as well as a ferminator for fermenting chilli mash. They're cheap and chearful, not had one go bang yet, and they're powering oil filled radiators, bench heaters and fridges. Fantastic little beasts.
I used that controller for my laser chiller I built from an air conditioner. Nice it has a compressor rest function. I set a 3 minute delay between cycles as many compressors require. It has been working very well and keeps my 130 watt Co2 laser at the perfect temp. I used a low voltage and and external high quality relay for switching ac voltage.
Theres so many cool uses listed in the comments, so far yours has got to be the coolest. I'm not smart enough to build them but I've always found lasers fascinating
@@electrowizard2000 each manufacture will have optimal temp ratings.... usually less than 20c. I run my chiller at 12c and the tube stays at 15c at 90%. I set the max current to 90% to extend tube life. 10,000 hours rating on this tube if run within spec.
I've been using a nearly identical one (humidity instead of temperature) to control a food dehydrator for drying 3d printer filament for several months, 120v version. No complaints so far.
In our laboratory, (no longer in existence, company restructure etc) we had large water heating tanks (proprietry) to test ground samples, they had exactly the same control panels as these, but the internal relays kept sticking and the water would boil away (the tanks were left running 24-7 over several days to complete a test), it was obvious that the internal relays were woefully inadequate to switch the heating element loads on and off, so I wired external 30 amp relays (RS components), in a similar fashion to the unit you showed towards the end of the video (21.13), and they worked perfectly after that...
I also have a couple of 240V / 40A versions that I use for brewery water heaters. They've worked happily for a few years now after a normal mains voltage one went smokily overloaded. I use normal mains ones to run a big fridge, small fermentation heaters, greenhouse propagators. One thing I would recommend is putting them in metal cases. They're cheap and disposable but they also fail.
I've used a similar device for year to control the temperature in a mini-fridge that was being used as a cheese cave. Though the one I was using was mains powered (120v) and had more buttons and configuration options. I recall that I could set an audible alarm for when the temperature went well below or above the set points.
Great to see you finally look at this. These are quite commonly used for fermentation temperature control. They always crop up as a cheaper alternative to Inkbirds and I've even seen them in professional breweries. Would be interesting to see the guts of the Inkbird in comparison.
Funny to see the first DC one you pulled apart has the creepage distance PCB cuts on both the relay contacts and power input, then subsequently the AC one doesn't have them (and of course the second DC one didn't either).
Iv'e been using a 110v version to turn a chest freezer to epoxy storage (keeps it at below 50f) for many years. They work great and my first one lasted about 5 years and the current one is on year 7 right now. I sell the epoxy and it has to be stored somewhat cool
Ha, the STC-1000 for a number of years has been the favorite heating/cooling modules for homebrewers for beer temp control during fermentation and to control the temps on our keezer beer taps. Eventually a company noticed we were ordering these cheap buggers and repackaged them as the "Ink Bird" controller for brewers. Also before home Sous-Vide immersion circulators were under $1000 I cooked using them with a coffee urn and an aquarium pump to move the water.
My freezer control panel broke last weekend, luckily I had a few STC-1000 on the shelf. The freezer only had the probe and three wires, neutral and line in and line out to the compressor
I use STC-3028 (temperature and humidity) line voltage controllers for a 250 watt heater and a humidifier in my small greenhouses, and the only thing that seems to be common between all them is the board and the case they are in. I actually like them because they are cheap, if they go bang, I can toss it in my spare parts bucket, and throw another one in service. I've noticed some use a 3 wire temp/humidity sensor, and some use a 4 wire sensor. They seem to work well enough, and since I'm in the greenhouses daily, it's pretty easy to tell quickly if they've gone up in smoke. Some day I might try more expensive controllers, but for now, they work well enough.
I wonder if any of the 12V or 24V ones get accidentally shipped as "mains AC" units. The fact that they are pretty much the same externally is a bit creepy. Plug it in and end up with a nice smoke and fireworks show, with a temperature reading of "flames."
I've been meaning to build a thermostat/hygrostat unit for my reptiles and other animals but haven't had the resources and time to start. For now I've been using cheap mains heating pad thermostats (iPower BNQ-T7B(H)) and a lot of manual monitoring for humidity and just verifying temperatures with an IR gun. Thank you, as always, Clive for your insights. I think I might go with a similar setup using one of these with redundancy. (A unit designed and sold for use with reptiles and animals with all the features I desire are $300, another reason I want to build my own)
I built a number of these for use with reptiles, controlling heatcords, mats and ceramic emitters. Also used one for my incubator (small wine fridge) and achieved very constant hatch rates. I thoroughly recommend them.
@@Mad4400 That is awesome. I really appreciate knowing that someone's use case is similar to mine. Did you put them into enclosures or just use them as is? Thanks a bunch!
I'm also using one of these for my reptile incubator, which is basically just a big chunk of styrofoam with a lid that has a hole cut into it for a window. The hole is then covered with some clear acrylic. It works pretty well and the hatch rates are solid.
for the 'industrial grade' controllers, usually uses output for solid state relays. this way its possible to control the firing of heater at high rate for PID control and at zero crossing. prolonging life of the 'contactor' and the heater itself.
With more than a grain of salt... I have a unit like this controlling a 1500 watt (100v) heater coil on a smoker that has been perfect for over 8 years so far. You never know what you might get!
Buy the mains powered one (if its the same price as 12V) because you then have two options to power it, I had a mains powered one that blew its input circuitry, and i just traced the tracks and used it on 12V.
The reason there are multiple sensor connection points on the main PCB is because the company that makes the STC-1000 also makes a version (STC-3008) that is a dual temperature controller and uses two sensors. They also make a couple of humidity controllers (DHC-100 and STC-3028) that use 3 wire sensors. We use a custom programmed version of the STC-1000 and have over 1000 of them in the field and have had very few problems with them.
I used one of these on a friends converted fridge for home brewing. It just had a heat pad in the fridge and we had a 60l brew drum which we just fit into the fridge so he could do 45l batches.
I have 6 of these running dye heaters, they work well. I did not use the stock relays though, they were de-soldered and wires were ran to the existing terminal block and wired to external solid state relays. I also updated the tags showing that they were modified.
Wondering if I need to shoe horn a 16A relay into mine, as using it for a 2kw heater (so 8.5A) and it the relay does get slightly toasty, i'm not hugely confident in cheap relays, even if they do say 10A 240v. I've got some 16A Omron 12v relays with the same pin layout, but slightly taller.
The best approach may be to do what the commercial refrigeration controllers do. Use a 12V unit and external 12V relay to switch the high load. The 12V units are more reliable and the relay can be chosen for the load and changed if needed.
Been running 250VAC STC-1000s for brewing temp control for many years. Lovely units for the price. One of mine is now 10 years old and still working 100%. But yes, don't over-stress the internal relays, I'd say 10A @ 250V is optimistic: 2.5kW would cook the relay. I'd say half that is safe: a large domestic fridges, freezer or smallish heaters would be the right unit to control, considering the inrush load. Industrial size fridges or heaters would require external relays.
I bought a version designed for thermoelectric devices which swapped the polarity of the output for heating or cooling. It's used for brewing beer so seasonally heats or cools. It has been switching 6A @ 12V for about 8 years with no issues. 12 Aussie dollars delivered back then.
As a few others have mentioned, I'd love to see you investigate an Inkbird one. I have two Inkbirds which I used over the winter to precisely heat rooms - very accurate, useful and energy saving indeed. I also have the humidity variant which is also proving accurate and reliable - the huimidistats built into dehumidifiers are often wildly inaccurate. I swapped out the generic relays with Omron ones - the STC-1000 relays look like Omron G5LE pattern clones.
Fitted a single relay version into a enclosure switching a 20amp contactor and single switched socket outlet as a portable heavy duty heat controller works a treat.
I probably have the deluxe version because mine got the buzzer populated. Probably the deluxe plus version have the humidity sensor thing and have a double throw relay. I have mine used for about 3 years now on a fridge with broken thermostat and planning to rip those internal power supply and use external power brick and relay.
I am using this in my refrigerator after the OEM thermostat failed twice. Using the 240Vac version and the 'cool' relay is driving the compressor (~125W) directly. As you told, the relays and the SMPS part are which I'm concerned about :)
I used one of those to control a mini-fridge that was left out in the sun and blew up the thermal control. I duct taped it to the top of the fridge and it worked for years. Great deal for around $10.
I've seen some of those with dual sensor sold as a differential or relative thermostat. This is where it compares the temperature of the two sensors and turns on if the difference is high enough. Usually combined with absolute, so for example T1 at 30C minimum and T2 5C minimum difference. Often used for solar thermal collectors, to control the pump used to transfer heat into storage.
I used one of these by Inkbird to convert a chest freezer to a kegerator and another to convert an analog croc pot to a pretty passable sous vide cooker. Been thinking of using them in an automated brewing setup too. The kegerator has been running continuously for many years now.
Theses are fantastic units for the price, I have used them in a many of projects from aquariums to walk in chillers/freezers to saunas, even put one in place for temporary use for the radiator fan on the van, always with external relays as never trusted the tiny little things in there, buy they have proven to otherwise be very reliable
I've been using these as a fail-safe for aquarium heaters for probably a decade now. Heaters are dodgy, love to fail open and cook your fish. I've had two do exactly that and didnt even notice as these things saved the day.
I've used thermostat modules called w1209 in a few project. They are very cheap and their software looks similar but they have only one puny little relay with 1 contact. And because there is only one contact, in the menu there is a setting where you choose whether you are using the module for cooling or heating.
Aimed at home brew market. Ive used a 240 volt one for years. Runnkng fridhe and heater belt. Safety issues include no segregation at terminals, single pole relays.
@6:28 do you know if you can get thermal cut outs that work the other way... I would like one that would cut out at 2C so that the contents of the fridge (hibernating animals) would never freeze.
14:27 Gotta love the fake ST Microelectronics logo on the voltage regulator being so Barbapapa that it technically isn't an ST Microelectronics logo anymore.
I use one of these controllers to run the freeze and harvest cycles on my ice machine after the thermostat failed, switches a contactor, and has been perfect for years, creates much more consistent ice than the thermostat ever did
I'm using a mains powered one to control an old under-counter fridge repurposed as "climate controlled" cabinet in my shed to store paint etc. Put a small heater element in the fridge as well to heat it in winter. So far it has been running for about a year. Just to be safe I put it in one of those extruded aluminium cases, outside the fridge. Would be fun to actually try to switch 10A with those relays, I bet it will grenade within a few cycles.
Thanks for showing me these. I always wondered what they were / where to get the simple stuff to tinker around with. At 11:21 - The Relays don't have anti-tracking slots for the Mains voltage unit. What voltage are the relays running? I couldn't really understand that from the video - but I would expect that the relays would run the input voltage to the output-unit?
Another main use for dual temperature sensors is to measure the outside temperature to optimized the regulation regime for a central heating boiler or pump. If it's cold outside, the building will need a bigger supply of heat to the local regulators in rooms.
There are probably modes/contacts/bridges for 3 or 4-wire PTC connection for lead-resistance compensation, that is: you present a current trough the PTC and measure the (returned) voltage at the resistor instead of at the connector. That is not needed for a fixed length connector, but can be helpful if the sensor is quite some distance away, like 15 meters, when the resistance of the wires become more than a couple ohms.
I've got an STC controller on a ceramic kiln. I believe it stands for Stoke Temperature Controllers, Stoke being the centre of the Potteries in the UK. My controller uses an AI chip that contains a neural network. The values in the neural network adjust themselves by monitoring the temperature and rate of change to achieve the desired heating and cooling ramps which is important in ceramics
I have a couple of these, they work just fine on mains voltage, maybe some things aren't ideal, but they certainly get the job done. They also have a model that runs in Fahrenheit, which gives you a little more granularity in your adjustments. Also, on the topic of relays, I don't think they're 10A relays, maybe for slow, low inductance, resistive loads, but for motor loads, I wouldn't run more than 3A or so. If you're turning on and off a motor, you're going to have a bad time. Also, it's not difficult to toss a couple larger relays in these, those kinda things are more or less lego, and even with nice relays, it's still way cheaper than any other option tbh. The big thing is to mount them in a metal box, and ground that box, and use it on a GFI circuit. That'll make it much much safer all around.
I have taken apart many coffee makers, and they rely on a thermal cut out switch that cycles the appliance on and off to warm your coffee pot all morning. That is a part that if it fails,1500 watts of power to the heating coil could start a fire.
But there should be another thermal cutout that will permanently cut power to prevent fire in case the operating thermostat fails in the closed condition.
Hi Clive . I got delivered a 220V version rather than a 12v version I ordered and rather than send back I decided to use. I mounted it on top of my metal earthed chassis psu. Rather than use the NTC that came with it, I decided to use the NTC on my 3d printers heat bed. Stupidly I was connecting it with mains going into the controller and managed to short the NTC output to the Earth metal chassis of my PSU with my screwdriver. Curiously though, the resulting flashover tripped my house ELCB and destroyed the controller. I deduced that the only way for this to happen was if mains supply had got onto the thermistor somehow so I watched your video with interest. Don’t know if it was a manufacturing error, lack of insulation or poor design but Id definitely stay away from the 220v version as getting 220v on your 3d printer chassis would be a bad day…
Happy to see this video. I've got an Inkbird ITC 2000 which is very similar but is 110v, has a big brown transformer inside, and what looks like a buzzer. Tried using it as a room thermometer but consistently read way too high. Now have no clue as to what to use it for.
I attached an air conditioner relay to the internal relays. Works great for higher power consumption. Mine is switchable between Celsius and Fahrenheit.
The extra thermistor input would be an evaporator probe for, say, a walk in fridge or especially a walk in freezer, where a heating element or hot gas is used to defrost the evaporator at set intervals & you need to sense that temp for a preset defrost termination temp. or set time -whichever occurs first.
Just for reference. Your standard industrial control stuff these days runs at 24 volt DC for the control circuitry. Unless something you're doing is fairly trivial I would stick to the standard. It also opens you up to acquiring all kinds of nice used parts from the industrial side.
Amazon (US, anyway) has the actual Inkbird 12V units for US$17, and they can be switched between C and F. I just grabbed one to turn a Peltier cooler into a place to ferment buttermilk. Depending on how it goes, I will grab another to convert an old refrigerator to age homemade cheese.
Great video as always, interesting as we have these (or very similar dual temp version) in the vans at work (supermarket grocery delivery) for the chiller/freezer compartments.
There is a dual version with two thermistors and two displays so the base board would seem to be made for both just change the front panel and display board.
Hi Clive this is not a criticism it's just something I was thinking of from my past where we used lots of control gear on critical processes to ensure they were kept in check at all times and the meters were manually checked using a Calibrated handheld meter by technicians from every hour to once a day dependant upon the process and how stable or critical it was. So although I could verify, as you did, the meter against the one that there which was calibrated if they were the same I would still have to have the new meter Calibrated by a third parting because of the extremely tight specifications; Often I could get them Calibrated when I brought them with a Certification but they have to be recalibrated every 6 months or maybe one year again dependant on what a failure would potentially cause. So although in your case it was not required to be calibrated to those extents it's always worth bearing in mind or probably ignoring it altogether and let the tech people sort it out. After 36 years they broke me, so I no longer have to follow British Standards or try to work out what they meant .💩 Thank you Clive for all your content, it's wonderful and this video suddenly brought back my past looking at the control gear
Depending on the micro in use (there appears to be a couple) there is opensource firmware available that adds functionality, etc.. As shown in Big Clive's video there can be different micro/ICs used on the logic/display board. In fact an STC-1000 I have has completely different 'power/relay' board (and logic/display board) to the ones shown in the video here. Unfortunately I haven't found a datasheet on the micro yet - though the logic/display board has labelled ISP header.
Hey Clive, Did anyone notice...? those three components on the 12v board (the second set of "thermistor components") show a 10k resistor in the C9 spot, and a cap in the R23 spot... I think you are correct to say they do nothing!...LOL
Ah ha! I was looking for a low voltage thermostat with an adjustable differential to use with my pellet stove! Using a standard thermostat with a pellet stove results in it cycling on and off constantly-the typical thermostats usually have a 1 degree differential. The stoves take about 20 min to shutdown completely, and about 5-10 min to power up and start producing heat. For me, an 8-10 degree (F) differential is perfect! (As well as time delays) thanks for the video!
So 5°C differential (conversion factor is 5/9).
Well it comes with a weaker thermocouple so if youre taking really high temps you might be out of luck. Not sure if theyll accept a k type.
But, if youre in the us, Harbor Freignt sells a $23 multimeter that comes with its own k type thermocouple.
them microshuntroller is en2apment for the mnd..... dont buye until e2e2 AT HAND
Must be something in the ether. Yesterday I dug out a single relay version of this style of device that has been lurking in my 'future projects' box for years, with the intention to make something with it, then that evening, I saw this video. Strange alignments!
Can we have a Big Clive and Atomic Shrimp crossover?
Atomic Big Shrimp Clive
@@LuminalSpoon Big Atomic Clive Shrimp .
I vote a sous vide controller. I made a simple 'inline' setup with an old extension lead and an enclosure. Slow cooker with the probe in it for the bath.
Best steak I've ever eaten, from the cheapest cuts possible (right up your street!!)
@@joelaw728 yeah. Sous vide, or temperature control for cheese making, or for a cheese maturing fridge. There are a lot of applications for fine temperature control that I could make use of
@@AtomicShrimp I use mine to thermally control my 3d printer cupboard (keeps the filament dry)
I've been using STC-1000's for temperature control for my aquariums for years, with the oldest one being 6 years old. Simple, accurate, and cheap. The heat and cooling control is amazing. I have both heaters and chillers on my tanks and by using one controller, it eliminates the risk of having both the heaters and chiller on at the same time. Highly recommend them.
Out of curiosity, what chiller are you running?
@@ALAPINO EcoPlus 1.5hp, and 2 aqua euro 1/10th hp. (Separate Tanks/systems).
All the chillers and heaters have their own thermostats also, so I utilize those as a redundant cut off.
For example, System temp is set to 78°, the STC is also set there with a 1° deviation. So the main (STC)temp range is 77-79°, therefore I have the chiller set to 76° and the heaters set to 80° on their built in thermostat. If the STC was to fail closed, the heater/chiller will shut itself off once it reached its own set point.
This helps prevent them from getting stuck on and freezing or cooking the tank.
@@noahsheehan7824 Cheers! Thanks for the information!
That's exactly why I'm leaning towards something like an STC, cost effective redundancy. My old home gets very cold in the winter and very hot in the summer. Not ideal for the animals we keep. :P
@@ALAPINO Awesome! Glad I could help!
I'm using them for exactly the same function although I don't use the cooling function, just the heating side. I set the aquarium heater to a couple of degrees higher than optimum so that if this unit should fail in the 'on' position the thermostat within the heater will turn off before the water temperature gets too drastically high. I have had just about all types and makes of aquarium heaters and I have yet to find one that is reliable and keeps the same temperature, it seems that because most of them use a bimetal strip they will alter over time. The greatest advantage is that I can check the temperature of all my 6 tanks just by glancing at them from a distance, the majority of aquarium thermometers are a total pain to read.
I LOVE THE STC-1000! I have one I installed to control a deep freezer, and it has reliably served for at least 5 years now. Never an issue, perfect absolutely perfect little device.
I came across these PID controllers when I was upgrading/modding my Gaggia Classic Pro espresso machine. The normal bimetallic controller would control the boiler approximately within 10 degrees which if you're obsessed with espresso is no beuno. You can set the temp precisely on them and these little buggers will keep the boiler within a degree. I've also seen them being shoehorned into Rancillio Silvia machines.
Shades of Coffee fan?
I live in an RV (caravan) in Mesa, AZ where it can get to 120F (50C) in the summer. The back of the refrigerator is exposed to the outside and has a problem operating above 85F (30C) so I bought one of these to switch on a small fan at that temperature so that it blows on the refrigerator coils. This works pretty well up to an outside temperature of 105F (40C); after that, nothing will help and the temperature inside the refrigerator will go up to around 50F (10C). The refrigerator operates on 12v so I hooked it up to the 12v line coming into the back, and the device will work even when I'm on a trip and not connected to shore power. My project for this summer is to add a second fan that will blow cold air from inside the trailer into the area behind the refrigerator to increase the efficiency of the refrigerator on very hot days.
I've thought about adding a fan to my rv fridge as well. Good to know one of these will work. What fan did you use?
@@joegroom3195 I bought a 12032 brushless DC cooling blower fan (2 pin) from eBay. I bought it for $7.50 but current prices seem to be around $20.
Seems about right for controlling a fridge full of Lager beer during fermentation! Also love the pro tip regarding relay failure that can be mitigated with a bimetallic switch and a neon bulb + resistor as failure indicator placed across the switch. Neat!
Thanks for sharing!
These aren't the same units, but I learned not to trust the relays in these types of things after a PID controller running some simple resistive heating tape managed to fail after only a few months. The relay got stuck in some halfway-closed state and emitted a bunch of smoke. After that, I switched to having the relays in these switch a solid-state relay that would switch the real load. More expensive and less efficient due to the drop in the SSR, but never had problems after that.
I use one of the Chinese PID controllers in a lab oven. (moderate temperatures
There's a substantial difference between an ordinary relay and a contactor: the latter is built to handle much more current and is arc flash resistant. In resistive heating or other high-current applications, a contactor is usually the safest choice. SSRs are also good, but beware that SSRs can sometimes fail and when they do, they usually fail closed - meaning the circuit stays live.
@@petergamache5368 Hence, the need for a thermal fuse in heating applications. The actuating circuit can fail with contactor permanently activated. Belt and braces for safety is a good rule of thumb. In my lab application, the heater is only 75W.
I've been using one of these for ten years! We use it to drive a heating pad, so our parrots are nice and comfy during our chilly winter nights, and it's been absolutely reliable. Mind you the load switched is only 25W (so 100mA) resistive. Easy to set up, and easy to get parts for (important for when "they" chew through the NTC probe cable!)
I've used one to cool a fermenting beer, to 18°C in a 21°C room, it ran an aquarium pump that sat in a cooler filled with ice water, replaced ice as needed. It worked well for that at least, ran for about a week.
That's cool. How much ice did you end up needing for that? Was it a once-a-day 10 pound ice bag thing?
I used 3 of these (mains voltage type) to control three (Beko) domestic full-sized chest freezers, in order to maintain them in the range -25 to -18 degrees C. This was required to maintain chemical thermal blocks within a known temperature range prior to use in pharma shipping of cold chain products. They (and the freezers plugged into them) worked flawlessly over 3 years, at which time we left that business. Great to see the innards and learn of their circuitry, as always. Like you suggested, I always kept two units as spares (given the low cost) but they were never needed. I would happily use again, should the need arise.
I've had a 110v one in operation since 2016, It is used as a low temp cutoff for an array of server fans propped up in a window to cool off my room.
it has switched up to 5 amps of 12v for years, but usually it's ran on a lower voltage unless its quite hot.
they are great units for the price. at just $15 I've ended up with more of them now to just use as thermometers for various things. the relays are an added bonus at that point
I use one of these as a "freeze guard" on our central AC unit. I threw it in while I was waiting on some R22 a few years back but after I fixed the issue and recharged the system, I ended up leaving it on just as a failsafe. If my suction line gets below 5C, it cuts off the condenser and just lets the inside fan run by itself. Just set the cooling temp to 6C and a 1C swing. It's wired to always be on and only the condenser control line is switched thru it. I set the compressor delay to 10 minutes so if it *does* start to freeze, it'll kill the compressor for 10 minutes to let the evaporator thaw. I know 5C isn't freezing but if the suction is that low, icing has already started on the evaporator on the first few loops after the expansion point and once the first few turns start to freeze, the rest will ice pretty quick.
Great video as always Clive!
My experience has shown these relays to be incredibly dangerous.
They arc weld easily. I bought one with exposed PCB that runs on 12V and only one relay, but after a few months it wouldn't turn on the heater.
I found a relay like it on Digikey, and replaced it with a real Omron for about $10.
3 Years so far an no worries.
Mine's been running non stop for 2 yrs, did I get lucky?
@@Margarinetaylorgrease Rather depends on the load you're switching.
@@adrian_foden A fridge compressor.
Unfortunately, when last visiting the Omron website to get specs and catalogs, all I could find was marketing noise about products for hospitals etc.
Seems a bad trend among corporate website designers to hide their signature products under mountains of aspirations to enter new markets.
@@Margarinetaylorgrease Without looking at a snapshot of a current probe, it's hard to say how huge the current to the motor at startup is. It's high enough that prevents most power inverters to shut down.
If you have the experience, replace it with a known brand that matched that footprint. If you haven't done that before, don't start with this. Start with something less critical. Buy a better quality. Pay once, cry once.
This does look like a generic version of an inkbird temperature controller, which seems more robust from my experience while still being relatively inexpensive. I'd be interested in your take on an inkbird.
I have used ink birds twice with external SSR no problems.. nice to have cheap tech for projects
I've used an inkbird hooked up to a slow cooker to make yoghurt, with moderate levels of success.
@@charleslambert3368 moderate levels of success and yogurt = 😵💫🤢🤮😵
@Charles Lambert I've used one of these cheapies with a slow cooker for Sou Vide and also heating element for brewing and also with a freezer for lagering with great levels of success. They're not that bad.
They are amazing for the price. Used them for my resin heating chamber and chiller.
I used one of these to convert my dad's old analog electric smoker for his birthday. It made the smoker maintain a much more precise temperature. I got one that had a 30A relay built in.
For those that miss an important point: Switch/Relay ratings printed on them is _near always_ Max Amps at VAC unless actually says VDC and all for purely Resistive Loads. Look up data sheets and you find the rating for Inductive at best is 1/3 to 1/2 of Amps for given Max Volts. Even parts made by Omron and other well known brands have same markings on them and will burn with Inductive Loads. Motors, fluorescent and other lights with a ballast, transformer and more will burn down any switch point fast because of this. But Some Datasheets don't bother listing this info and many people burn out the contacts and worse...
So-called "definite purpose contactors" are rated in amps for an inductive load. Therefore a 40-amp definite purpose contactor is rated for a 40 amp inductive load. They're primarily used in HVAC applications to switch motors and compressors, and may only be available in USA/Canada.
Yes, when I tried to design my own relay boards I found this to be buried deep, and often with no useful numbers for individual products. Also the published information on prolonging contact life with snubber networks falls into the useless category of "measure your very specific finished product and redesign circuit for that specific situation", which is highly impractical when trying to make something intended for 3rd party use with unknown loads. As a workaround (never built and tested), I considered using a MOV to eat the back EMF from inductive loads, thus preventing excessive contact wear.
now i know why regardless if we over spec our relays, we always end up replacing them anyway just farther down the line
@@brianleeper5737 The Contactors goes by different names but they do use versions world wide. These are not cheap or available to general public in normal retail. In the U.S. you are often looking at Graybar and other industrial suppliers to buy them and meet Electric Codes.
I looked but Can't find exact JQC-3FF above. Others start same and FL-3FF-S-H the datasheets have No mention of Inductive loads. Contrast to Songle SRD-05VDC-SL-C (Used by Elegoo and many other Arduino/Pi kit makers) Datasheet rates Type C contacts Resistive Load 7A 28VDC, 10A 125VAC, 7A 240VAC Inductive Load 3A 28VDC, 3A 120VAC If part number end with A means Type A contacts rated for Resistive Load 10A 28VDC, 10A 240VAC Inductive Load 5A 28VDC, 5A 120VAC Omron sheets are similar with reduce I-loads for most relays.
Some Relays for Cars are made to handle 10 to 20 Amps at 20VDC because controls Fuel Pumps, AC Clutches, and more but they often wear out faster doing that vs Turning On Halogen Headlights pulling More amps then the motors/coils.
Same problem at home with standard wall switches burning up every few years at best controlling garbage disposers, fluorescent lights, etc.
Clive, I have the Inkbird ITC-1000F in my house, its very similar to yours but its display will support Centigrade and Ferinheight. Here in the USA that helps. It functions a little differently than the SCT-1000 but is the same case and connections. I have hot air oil heat so I have mounted the thermocouple into my dryer vent that I change to vent into the basement through filters. When the dryer vent reaches 75 deg F it turns on the fan in my furnace and dissipates the heat throughout the house along with the humidity in which is greatly needed in the winter. Works great!
I have two similar 240v units mounted in a box by my bed. I have one temp sensor in the bed at foot level under the electric blanket. I set this at 30c. The other unit is wired in series, measuring the room temp, set at 24c. The electric blanket is set on #3 ( full heat). All this is powered by a clock timer to run between 10:30 pm and 7:30 am April to September. I was so sick of waking up shivering at 3am or covered in sweat if it was a warm night. So now I have the Goldilocks setting and it is just great. Its has been running for nearly ten years. Plugged in last week for the on coming winter.
I've been using these with my fermentation fridge for years with an incandescent light bulb, and for controlling a freezer as a keg fridge. I also use Inkbird 308s but the non. WiFi version has occasional temperature transients that cause the fridge to kick in for a brief time occasionally (it's a known bug they know about) and its cali bration can shift. I find cheap stcs more reliable than 308s.
Well that explained things a lot better than any other Chanel I've seen. Cheers big Clive.
Agnone know where i can download the BigClive theme pack for windows? Every time I open a new program i want it to say "one moment please"
I use an Inkbird in a gutted out mini fridge for starting plant seeds. It runs a 40watt incandescent for heat and a couple of 80mm fans for cooling. A Defiant timer switch controls CFL lights. Hole sawed a bunch of holes for fresh air.
I think a return visit is required Clive, the relays and their real-life current switching capacity and the loads they're capable of dealing with are where the rubber hits the road. A brief run through the comments here says there is a story to be told.
Jumping into some of the datasheets for them is.... interesting!
I have a couple of these units here in Canada to control a freezer and fridge. So far they work great and yes I used an external relay for control. Love to fact that they readout actual temperature of your appliance. 👍
Love these things. I used one to make a sous vide machine out of our slow cooker. Must be a manual (not electronic) slow cooker.
Same here. Absolutely amazing results. Made mine using a basic enclosure box and an old extension lead. That way I can stick the probe and meat in any slow cooker; future proof and didn't need to modify my slow cooker :)
@@joelaw728 Great minds think alike? I can use my little friend to control the temperature of many things. I also am building another to use with a small freezer for a cheese cave.
I have once repaired a very similiar thermostat that controlled a fridge. Due to moisture build up, a leakage current was flowing over the pcb from live to neutral. This resulted in a trace of carbon which was conducting enough to short the live to neutral with a loud bang. I had to cut a slot into the PCB in order to remove the carbon trace and to gain a better separation between live and neutral.
I remember paying an OEM $700 for one of those for a hospital refrigerator. The management insisted we do it
And what would the cost of a full refrigerator's worth of medications be, if it failed? Probably a lot more than $700...
@@petergamache5368 Which more begs the question of why they were using an STC-1000 for such a critical application to begin with :\
I've been fermenting with two of these for 5-7 years. Using 120V power source and running a small refrigerators directly on the load side.
Hi mate. I used to work for a commercial cleaning equipment contractor. They supply a machine called a decarboniser. Using one of those to heat either 10,35,50 gallon water tanks using domestic elements used for central heating. It was a smaller part of their business but u used to replace approximately 5 of those controllers every week !!!
I have one of these units. I put my Ender3 in a 12-U enclosed/vented networking cabinet. The cabinet came with a pair of 120mm mains voltage fans. I routed the temperature probe wire through the cable chain onto the Z-Axis Rail so the probe is about 20mm above the print nozzle or the piece being printed. I have the temperature set to 37.7˚C (100˚F) with a 3˚C Differential. Compressor setting disabled and the fans connected to the cooling side. Nothing is connected to the heating side. This keeps the ambient temperature hot around the print but kicks the fans on if the temperature rises too much. I found it helps to prevent the print from warping and coming off the print surface during printing.
I have a few of these running, both mains and DC powered. One AC unit has been running for near 10 years controlling a cooling fan on my grid tie inverter system (non kosher).
Another DC unit has been controlling via a power relay a cooling fan on my Land Rover diesel, Lucas electrics have not managed to destroy it in 12 months so they must be tough.
I had 2 of the real Elitech versions of these in my hombrew set-up 10+ years ago, installed in a jiffy box with IEC connectors for input, heating (during fermentation in winter) and cooling (during fermentation in summer and to turn a freezer into beer keg fridge). Passed it onto my mate as I have no time for homebrewing anymore, but it's still going strong!
Elitech video recorded and coming soon.
been using these mains cheapies for heating/cooling various greenhouse and seedling tents as well as a ferminator for fermenting chilli mash. They're cheap and chearful, not had one go bang yet, and they're powering oil filled radiators, bench heaters and fridges. Fantastic little beasts.
I used that controller for my laser chiller I built from an air conditioner. Nice it has a compressor rest function. I set a 3 minute delay between cycles as many compressors require. It has been working very well and keeps my 130 watt Co2 laser at the perfect temp. I used a low voltage and and external high quality relay for switching ac voltage.
Theres so many cool uses listed in the comments, so far yours has got to be the coolest. I'm not smart enough to build them but I've always found lasers fascinating
@@goosenotmaverick1156 lol yeah, i built the laser cutter too. Its a beast!
What's your set temperature? Any data on tube life vs temperature? Thanks!
@@electrowizard2000 each manufacture will have optimal temp ratings.... usually less than 20c. I run my chiller at 12c and the tube stays at 15c at 90%. I set the max current to 90% to extend tube life. 10,000 hours rating on this tube if run within spec.
I've been using a nearly identical one (humidity instead of temperature) to control a food dehydrator for drying 3d printer filament for several months, 120v version. No complaints so far.
In our laboratory, (no longer in existence, company restructure etc) we had large water heating tanks (proprietry) to test ground samples, they had exactly the same control panels as these, but the internal relays kept sticking and the water would boil away (the tanks were left running 24-7 over several days to complete a test), it was obvious that the internal relays were woefully inadequate to switch the heating element loads on and off, so I wired external 30 amp relays (RS components), in a similar fashion to the unit you showed towards the end of the video (21.13), and they worked perfectly after that...
I also have a couple of 240V / 40A versions that I use for brewery water heaters. They've worked happily for a few years now after a normal mains voltage one went smokily overloaded. I use normal mains ones to run a big fridge, small fermentation heaters, greenhouse propagators. One thing I would recommend is putting them in metal cases. They're cheap and disposable but they also fail.
been running these for my household fridge and freezer for ages. brilliant for the price
I've used a similar device for year to control the temperature in a mini-fridge that was being used as a cheese cave. Though the one I was using was mains powered (120v) and had more buttons and configuration options. I recall that I could set an audible alarm for when the temperature went well below or above the set points.
Great to see you finally look at this. These are quite commonly used for fermentation temperature control. They always crop up as a cheaper alternative to Inkbirds and I've even seen them in professional breweries. Would be interesting to see the guts of the Inkbird in comparison.
Funny to see the first DC one you pulled apart has the creepage distance PCB cuts on both the relay contacts and power input, then subsequently the AC one doesn't have them (and of course the second DC one didn't either).
Iv'e been using a 110v version to turn a chest freezer to epoxy storage (keeps it at below 50f) for many years. They work great and my first one lasted about 5 years and the current one is on year 7 right now. I sell the epoxy and it has to be stored somewhat cool
Ha, the STC-1000 for a number of years has been the favorite heating/cooling modules for homebrewers for beer temp control during fermentation and to control the temps on our keezer beer taps. Eventually a company noticed we were ordering these cheap buggers and repackaged them as the "Ink Bird" controller for brewers. Also before home Sous-Vide immersion circulators were under $1000 I cooked using them with a coffee urn and an aquarium pump to move the water.
My freezer control panel broke last weekend, luckily I had a few STC-1000 on the shelf. The freezer only had the probe and three wires, neutral and line in and line out to the compressor
I use STC-3028 (temperature and humidity) line voltage controllers for a 250 watt heater and a humidifier in my small greenhouses, and the only thing that seems to be common between all them is the board and the case they are in. I actually like them because they are cheap, if they go bang, I can toss it in my spare parts bucket, and throw another one in service. I've noticed some use a 3 wire temp/humidity sensor, and some use a 4 wire sensor. They seem to work well enough, and since I'm in the greenhouses daily, it's pretty easy to tell quickly if they've gone up in smoke. Some day I might try more expensive controllers, but for now, they work well enough.
I wonder if any of the 12V or 24V ones get accidentally shipped as "mains AC" units. The fact that they are pretty much the same externally is a bit creepy. Plug it in and end up with a nice smoke and fireworks show, with a temperature reading of "flames."
I've been meaning to build a thermostat/hygrostat unit for my reptiles and other animals but haven't had the resources and time to start.
For now I've been using cheap mains heating pad thermostats (iPower BNQ-T7B(H)) and a lot of manual monitoring for humidity and just verifying temperatures with an IR gun.
Thank you, as always, Clive for your insights. I think I might go with a similar setup using one of these with redundancy.
(A unit designed and sold for use with reptiles and animals with all the features I desire are $300, another reason I want to build my own)
I built a number of these for use with reptiles, controlling heatcords, mats and ceramic emitters. Also used one for my incubator (small wine fridge) and achieved very constant hatch rates. I thoroughly recommend them.
@@Mad4400 That is awesome. I really appreciate knowing that someone's use case is similar to mine.
Did you put them into enclosures or just use them as is?
Thanks a bunch!
I'm also using one of these for my reptile incubator, which is basically just a big chunk of styrofoam with a lid that has a hole cut into it for a window. The hole is then covered with some clear acrylic. It works pretty well and the hatch rates are solid.
for the 'industrial grade' controllers, usually uses output for solid state relays. this way its possible to control the firing of heater at high rate for PID control and at zero crossing. prolonging life of the 'contactor' and the heater itself.
With more than a grain of salt... I have a unit like this controlling a 1500 watt (100v) heater coil on a smoker that has been perfect for over 8 years so far. You never know what you might get!
Buy the mains powered one (if its the same price as 12V) because you then have two options to power it, I had a mains powered one that blew its input circuitry, and i just traced the tracks and used it on 12V.
The reason there are multiple sensor connection points on the main PCB is because the company that makes the STC-1000 also makes a version (STC-3008) that is a dual temperature controller and uses two sensors. They also make a couple of humidity controllers (DHC-100 and STC-3028) that use 3 wire sensors. We use a custom programmed version of the STC-1000 and have over 1000 of them in the field and have had very few problems with them.
I used one of these on a friends converted fridge for home brewing. It just had a heat pad in the fridge and we had a 60l brew drum which we just fit into the fridge so he could do 45l batches.
Been using one of these for years on 240V to run my homebrewing fridge. Keeps the ferment going at 17-18ish Celsius. Haven't had any issues.
I have 6 of these running dye heaters, they work well.
I did not use the stock relays though, they were de-soldered and wires were ran to the existing terminal block
and wired to external solid state relays. I also updated the tags showing that they were modified.
Wondering if I need to shoe horn a 16A relay into mine, as using it for a 2kw heater (so 8.5A) and it the relay does get slightly toasty, i'm not hugely confident in cheap relays, even if they do say 10A 240v. I've got some 16A Omron 12v relays with the same pin layout, but slightly taller.
The best approach may be to do what the commercial refrigeration controllers do. Use a 12V unit and external 12V relay to switch the high load. The 12V units are more reliable and the relay can be chosen for the load and changed if needed.
Been running 250VAC STC-1000s for brewing temp control for many years. Lovely units for the price. One of mine is now 10 years old and still working 100%. But yes, don't over-stress the internal relays, I'd say 10A @ 250V is optimistic: 2.5kW would cook the relay. I'd say half that is safe: a large domestic fridges, freezer or smallish heaters would be the right unit to control, considering the inrush load. Industrial size fridges or heaters would require external relays.
I bought a version designed for thermoelectric devices which swapped the polarity of the output for heating or cooling.
It's used for brewing beer so seasonally heats or cools.
It has been switching 6A @ 12V for about 8 years with no issues. 12 Aussie dollars delivered back then.
As a few others have mentioned, I'd love to see you investigate an Inkbird one. I have two Inkbirds which I used over the winter to precisely heat rooms - very accurate, useful and energy saving indeed. I also have the humidity variant which is also proving accurate and reliable - the huimidistats built into dehumidifiers are often wildly inaccurate. I swapped out the generic relays with Omron ones - the STC-1000 relays look like Omron G5LE pattern clones.
Fitted a single relay version into a enclosure switching a 20amp contactor and single switched socket outlet as a portable heavy duty heat controller works a treat.
I probably have the deluxe version because mine got the buzzer populated. Probably the deluxe plus version have the humidity sensor thing and have a double throw relay. I have mine used for about 3 years now on a fridge with broken thermostat and planning to rip those internal power supply and use external power brick and relay.
I am using this in my refrigerator after the OEM thermostat failed twice. Using the 240Vac version and the 'cool' relay is driving the compressor (~125W) directly. As you told, the relays and the SMPS part are which I'm concerned about :)
I used one of those to control a mini-fridge that was left out in the sun and blew up the thermal control. I duct taped it to the top of the fridge and it worked for years. Great deal for around $10.
I've seen some of those with dual sensor sold as a differential or relative thermostat. This is where it compares the temperature of the two sensors and turns on if the difference is high enough. Usually combined with absolute, so for example T1 at 30C minimum and T2 5C minimum difference. Often used for solar thermal collectors, to control the pump used to transfer heat into storage.
I used one of these by Inkbird to convert a chest freezer to a kegerator and another to convert an analog croc pot to a pretty passable sous vide cooker. Been thinking of using them in an automated brewing setup too. The kegerator has been running continuously for many years now.
After reading up on sous vide, one has to balance the desire for food improvement over the chance of getting poisoned. Yikes!
Thank you dear Mr. Big Clive sir. Have a swell day!
Theses are fantastic units for the price, I have used them in a many of projects from aquariums to walk in chillers/freezers to saunas, even put one in place for temporary use for the radiator fan on the van, always with external relays as never trusted the tiny little things in there, buy they have proven to otherwise be very reliable
I've been using these as a fail-safe for aquarium heaters for probably a decade now.
Heaters are dodgy, love to fail open and cook your fish. I've had two do exactly that and didnt even notice as these things saved the day.
I thought you were supposed to cook fish ?
@@travisash8180
Hahaha
I've used thermostat modules called w1209 in a few project. They are very cheap and their software looks similar but they have only one puny little relay with 1 contact. And because there is only one contact, in the menu there is a setting where you choose whether you are using the module for cooling or heating.
Aimed at home brew market. Ive used a 240 volt one for years. Runnkng fridhe and heater belt. Safety issues include no segregation at terminals, single pole relays.
@6:28 do you know if you can get thermal cut outs that work the other way... I would like one that would cut out at 2C so that the contents of the fridge (hibernating animals) would never freeze.
"What's that?"
"Oh, that's the *_call engineer now_* light."
"Why is it covered with tape like that?"
"It keeps lighting up and I can't work out why."
Or "Oh it's just gone out again so we don't need to call them."
14:27 Gotta love the fake ST Microelectronics logo on the voltage regulator being so Barbapapa that it technically isn't an ST Microelectronics logo anymore.
Oh, it props-up my soul that I'm not the only one leaving Neons as indications to call "that guy who comes to fix things."
I use one of these controllers to run the freeze and harvest cycles on my ice machine after the thermostat failed, switches a contactor, and has been perfect for years, creates much more consistent ice than the thermostat ever did
I'm using a mains powered one to control an old under-counter fridge repurposed as "climate controlled" cabinet in my shed to store paint etc. Put a small heater element in the fridge as well to heat it in winter. So far it has been running for about a year. Just to be safe I put it in one of those extruded aluminium cases, outside the fridge.
Would be fun to actually try to switch 10A with those relays, I bet it will grenade within a few cycles.
Thanks for showing me these. I always wondered what they were / where to get the simple stuff to tinker around with.
At 11:21 - The Relays don't have anti-tracking slots for the Mains voltage unit.
What voltage are the relays running? I couldn't really understand that from the video - but I would expect that the relays would run the input voltage to the output-unit?
I love these things, I have a slightly different one connected to a box fan I shove in my window to cool my room off during the evening!
Another main use for dual temperature sensors is to measure the outside temperature to optimized the regulation regime for a central heating boiler or pump. If it's cold outside, the building will need a bigger supply of heat to the local regulators in rooms.
There are probably modes/contacts/bridges for 3 or 4-wire PTC connection for lead-resistance compensation, that is: you present a current trough the PTC and measure the (returned) voltage at the resistor instead of at the connector. That is not needed for a fixed length connector, but can be helpful if the sensor is quite some distance away, like 15 meters, when the resistance of the wires become more than a couple ohms.
It's purely a simple NTC divider. No compensation.
Can we please go over the InkBird Reptile/aquarium thermostats Big Clive?! Please?!
I've got an STC controller on a ceramic kiln. I believe it stands for Stoke Temperature Controllers, Stoke being the centre of the Potteries in the UK.
My controller uses an AI chip that contains a neural network. The values in the neural network adjust themselves by monitoring the temperature and rate of change to achieve the desired heating and cooling ramps which is important in ceramics
I have a couple of these, they work just fine on mains voltage, maybe some things aren't ideal, but they certainly get the job done.
They also have a model that runs in Fahrenheit, which gives you a little more granularity in your adjustments. Also, on the topic of relays, I don't think they're 10A relays, maybe for slow, low inductance, resistive loads, but for motor loads, I wouldn't run more than 3A or so. If you're turning on and off a motor, you're going to have a bad time.
Also, it's not difficult to toss a couple larger relays in these, those kinda things are more or less lego, and even with nice relays, it's still way cheaper than any other option tbh.
The big thing is to mount them in a metal box, and ground that box, and use it on a GFI circuit. That'll make it much much safer all around.
I have taken apart many coffee makers, and they rely on a thermal cut out switch that cycles the appliance on and off to warm your coffee pot all morning. That is a part that if it fails,1500 watts of power to the heating coil could start a fire.
But there should be another thermal cutout that will permanently cut power to prevent fire in case the operating thermostat fails in the closed condition.
I think your right, some have an extra back-up.
I'm using the variations with 10V output to a solid state relay in several applications where heaters are switched.
Hi Clive . I got delivered a 220V version rather than a 12v version I ordered and rather than send back I decided to use. I mounted it on top of my metal earthed chassis psu. Rather than use the NTC that came with it, I decided to use the NTC on my 3d printers heat bed. Stupidly I was connecting it with mains going into the controller and managed to short the NTC output to the Earth metal chassis of my PSU with my screwdriver. Curiously though, the resulting flashover tripped my house ELCB and destroyed the controller. I deduced that the only way for this to happen was if mains supply had got onto the thermistor somehow so I watched your video with interest. Don’t know if it was a manufacturing error, lack of insulation or poor design but Id definitely stay away from the 220v version as getting 220v on your 3d printer chassis would be a bad day…
Happy to see this video. I've got an Inkbird ITC 2000 which is very similar but is 110v, has a big brown transformer inside, and what looks like a buzzer. Tried using it as a room thermometer but consistently read way too high. Now have no clue as to what to use it for.
It should be able to be calibrated if you have a trustworthy reference.
Aah the go to device for homebrewers there was a 30a one for sale at one point, handy for 3kw elements in kettles.
I have a 30A unit here in the queue.
I'm very glad it keeps the heating cooling on until it reaches the set temperature I need it for thermo fans and I don't want them going on off on off
I've used one of these to control for fermenting beer and also for my beer fridge (a chest freezer) for 10 years.
I attached an air conditioner relay to the internal relays. Works great for higher power consumption. Mine is switchable between Celsius and Fahrenheit.
0:55 So you could use them to trigger a solid state relay? Or contacter? How many amps do those draw (on the trigger side)?
It depends on the device. A solid state relay will only require around 20mA.
The extra thermistor input would be an evaporator probe for, say, a walk in fridge or especially a walk in freezer, where a heating element or hot gas is used to defrost the evaporator at set intervals & you need to sense that temp for a preset defrost termination temp. or set time -whichever occurs first.
Just for reference. Your standard industrial control stuff these days runs at 24 volt DC for the control circuitry. Unless something you're doing is fairly trivial I would stick to the standard. It also opens you up to acquiring all kinds of nice used parts from the industrial side.
Amazon (US, anyway) has the actual Inkbird 12V units for US$17, and they can be switched between C and F. I just grabbed one to turn a Peltier cooler into a place to ferment buttermilk. Depending on how it goes, I will grab another to convert an old refrigerator to age homemade cheese.
Great video as always, interesting as we have these (or very similar dual temp version) in the vans at work (supermarket grocery delivery) for the chiller/freezer compartments.
There is a dual version with two thermistors and two displays so the base board would seem to be made for both just change the front panel and display board.
Hi Clive this is not a criticism it's just something I was thinking of from my past where we used lots of control gear on critical processes to ensure they were kept in check at all times and the meters were manually checked using a Calibrated handheld meter by technicians from every hour to once a day dependant upon the process and how stable or critical it was. So although I could verify, as you did, the meter against the one that there which was calibrated if they were the same I would still have to have the new meter Calibrated by a third parting because of the extremely tight specifications; Often I could get them Calibrated when I brought them with a Certification but they have to be recalibrated every 6 months or maybe one year again dependant on what a failure would potentially cause. So although in your case it was not required to be calibrated to those extents it's always worth bearing in mind or probably ignoring it altogether and let the tech people sort it out.
After 36 years they broke me, so I no longer have to follow British Standards or try to work out what they meant .💩
Thank you Clive for all your content, it's wonderful and this video suddenly brought back my past looking at the control gear
Depending on the micro in use (there appears to be a couple) there is opensource firmware available that adds functionality, etc.. As shown in Big Clive's video there can be different micro/ICs used on the logic/display board.
In fact an STC-1000 I have has completely different 'power/relay' board (and logic/display board) to the ones shown in the video here. Unfortunately I haven't found a datasheet on the micro yet - though the logic/display board has labelled ISP header.
Hey Clive, Did anyone notice...? those three components on the 12v board (the second set of "thermistor components") show a 10k resistor in the C9 spot, and a cap in the R23 spot... I think you are correct to say they do nothing!...LOL