I believe the capacitor across the relay terminals is to stabilize the holding current. The current available from the resistive dropper is going to be extremely limited, and since it is half-wave rectified, that relay will tend to buzz. Certainly not something you want to risk happening when it's controlling the inductive transformer across mains.
I think you could replace the teflon sheet with some doubled over kapton tape. I have been using one of these for years, it hasn't failed me yet but the power connector on mine is like a crap midi connector.
i have been watching a lot of your videos lately, and they are great, i feel like i have learned very much (especially about LEDs) from you tearing down electrical items and showing us how they work, in fact i like that poundland items and cheap chinese things are the stuff you get, because often they seem simple enough that it would be possible for me to make my own version or use a particular trick they use in something i want to build. anyway, keep up the good work :)
***** The Poundland stuff is just perfect for hacking and modifying. You wouldn't believe how many bits of their products end up incorporated into the props and sets of TV and film productions. And if you mess something up it only costs a pound to replace, so you can have another go.
I used to work with an industrial one of these, bagging up 40-lb sacks of fertilizer. Needless to say, it gets very dramatic (and smelly) when the heating element breaks. It arced and burned right through the Teflon.
150W for the element and 150W in the transformer. Typically a 56VAC open circuit transformer, run horribly overloaded. I fix them all the time, but this one is the nastiest I have seen, the ones I buy are the metal cased versions, a little more but survive production use. Tape I buy in 2 sizes by the roll. Timer I always mod by adding a VDR across the relay contacts and adding a 220k resistor across the 2 wires to the pot so the max time is 4 seconds. Saves the element burning when time is turned too far. That timer board is the bad version, the ones I use have a SCR ( I use a C106D as a replacement) as the relay drive, and they are a lot more consistent in operation. Relays are luckily a part I can get for $1, and I use a lot of them. The cap across your relay coil is to prevent chattering of the relay as it pulls in, which will kill it very fast.
Seeing this delay design circuit basically one also can put a 555 module laying around tuned with a good solid state relay and add a batteries or supercaps or a power supply and that's it! Thank you for saving me the money and time buying and reverse engineering this!
The heat strip is probably a ribbon of nickel-chromium metal. Ni-chrome is in common usage as a heating element and also as a heated 'cheese cutter' for plastic foams.
The impulse sealer I had used a self-adhesive white 'cloth' covering the element. When I had to replace it, the dealership had a newer Teflon self-adhesive strip as well as the original clothy type. (technology moves on.) One reason these have become so cheap is because the 'technology' in them is primitive. Just a nichrome strip under Teflon with a timer module. The one I had, (my brother has it now,) used more industrial components. (See the RS Components line of sealers.)
There are models with cast iron chassis; it seems like paying slightly more than plastic ones is worth it if you're planning to use it a lot -- such as in kit manufacturing or component wholesale job.
Great video, went from such an easy product of sealing plastic bags to a mind bender trying to figure out all the math for a simple circuit. I was trying to follow along with the math I know of automotive DC circuits, but got stumped on how long the capacitors take to charge and then what voltage it would be to pass the last zener.
I bought one of these recently. There's been a few updates to the design: slightly less dodgy switch arrangement, screws at both ends of the element, slightly changed timer circuit (some values changed), potentiometer soldered directly to pcb. I modified mine by increasing the resistance of the timing resistor because at the maximum setting it wasn't quite as long as I wanted for some of the thickest foil bags I tried.
I think that element might be more likely nickel chromium heating element wire. It's a lot more stable than steel, even stainless. You can't tell I've taken a few things to bits myself can you?
I love my impulse heat sealer. Great for bagging parts each in their own section of a single packet. Put first lot of parts in, seal, second lot of parts, seal, etc. It is worth pulling the bottom plate off the unit when you buy to make sure the wiring is tidy and ensure the cut-out PCB and spade connectors are secured properly. I got mine on eBay and it didn't work on arrival due to one of the spade connectors popping off. 2 minutes work and it was sorted.
I have one myself which sat new in the box for ten years or more, also made in China, but much better made than this one. For one thing, the housing is a proper magnesium alloy casting. Also, the transformer is quite substantial, even when you consider that my unit is a 300w version. When I bought it from the person who ordered it through the mail ($5 from her yard sale), it did have a bit of shipping damage in the form of a small chip in the housing and a broken fuse holder. The only problem I found with the unit was that it didn't come with a grounding cord; I quickly rectified that, using one of the pillars cast into the housing as a grounding point.
I have one of these. In a tan metal enclosure (or was it pale blue...) instead of your blue enclosure. I've used it to seal up a few things for eBay sales. You can get shrink bags, seal it with this thing, then use a heat gun or hair dryer to shrink the bags. I'm in North America, so 120VAC power. (No idea what the circuitry in mine looks like.)
goes to show that cheaply made stuff doesnt have to be crappy and dangerous also seeing how simple it is idk why they use to be so expensive itd be interesting to see inside one of the old expensive ones to see if there was anything fundamentally different about them
These used to be popular for sealing in medical applications, everything in that sector gets a giant markup because it does. We had to replace these with fancier units as the business was swallowed up by larger companies, and validation requirements got more formal.
Those poly bagging machines that do frozen veggies have the same kind components. The jaw that seals the bag has 2 nichrome strips and a wire that cuts the bag. Refrigerated water goes through the jaw so it seals instantly. The nichrome strip on top seals the next bag to be filled, the one on the bottom seals the filled bag at the same time. After the bags are sealed the wire between them cuts the bag then the jaws open the bag falls off the teflon cloth strips. The wires went to solid state relays then a I/O board.
You can use them for heat sealing plastic cosmetics tubes as well. Did that one have a proper plug on it or the crappy 3 pin with no fuse in it like the one I took off mine?
Hi. Great informative video. Can I ask, can the element on a machine like this be replaced with a larger/wider one so it can make a wider seal in the plastic? Many thanks
Ty for your video, I've been meaning to get one of these but didn't know their cheap name :D I got one on order for an earth shattering $25 (about the same size as yours), don't have a use for it right this moment heh heh heh, but will come in handy for when I get around to playing with my Ammonium Persulphate (the tree hugger version of ferric chloride that we're all forced to use these days here in her majesties cotton wool convict colony) and dividing it up into smaller portions to better manage it's extremely hygroscopic nature. Unlike Ferric Chloride it's clear, which is kinda handy, but apparently can let off fumes (never noticed them) only problem is, it's far far far more temperature sensitive than Ferric Chloride, it's dead as a post at 20C, kinda sorta works at 30C but is much better at 40-50C........
The transformer probably has magnetic shunts to limit the o/p current, similar to an arc welder or microwave transformer. Couldnt quite see the trans in the vid, but it looks like all the e's and i's are inline, this will have been done to increase stray fields, another trick to limit saturation done in the above mentioned trans's.
The capacitor across the relay may be a delay before the relay releases to prevent re operation until the main cap discharges so the next operation gets the full time period
+Sparky Projects Either that, or it resists the sudden voltage spike when the relay turns on. The diode will prevent the back-EMF, but when the coil is energized it could cause a spike, and/or dip in the supply rail, which the cap might help mitigate?
A disappointing lack of sealing means it might not be so safe for kitchen use, but then for the price point I'm not terribly surprised. I suppose one could silicone the base up, since presumably the vent holes aren't really doing much?
Hey Clive. Long time viewer, first time commenter. Firstly, I love your videos; they're so real-life and informative (especially find the decriptions of the circuit diagrams useful, yet baffling at my particularly amateur stage) that I decided to go out and get my own soldering kit, multimeter and basic electronics kit and enjoying it so far, so thank you for that. A question I do have about this video is about the two resistors in parallel. Why would it be beneficial so put 2 10k resistors in parallel and get less resistance when they could have just used a 5k? Is it because if one fails it protects the circuit? Anyway, hope you're well and the weather's treating you better in the Isle of Man than it is in Wiltshire!
+Stephen Turley the resistor are usually rated for how much heat they can dissipate 1/4 watt 1/2 watt etc. the 2 10ks in parallel wouldn't get as hot as a single 5k with the same rating and resistors also get bigger the more heat they can dissipate so it may not have fit or it could be cheaper to use two 1/2w 10kohm then one 1w 5kohm resistor
i have electronics sourcing experience in a manufacturing plant. using 2 pcs of lower wattage is less expensive, why because low watt resistors are more common and therefore less expensive and more easily sourced. that is the major reason for choosing 2 pcs instead of 1 large wattage. electrically 2 pcs carries higher current.
ah...this ones familiar. Had to use them to seal bags at the food bank when our class did volunteer work there. So many pearl onions...the smell...it somehow permeated the rubber gloves we had to wear.... I hate onions so much
Thank you for your video, I'm on plans to put together a sealant material I have at home, resistance buy it. The voltage is applied to the ends of the heating resistance? 14V ac?
Hi Big Clive, thanks so much for the video, it was so helpful in understanding a heat sealer. I'm trying to remove the timing function on my impulse heat sealer so that I can heat a seal for as long as I press down on the sealer, but I'm not very well versed in circuits (only took one electrical engineering class in college). What would you do to get rid of the timing feature completely? Thanks in advance, and keep doing your videos!
+Diyi Zhu You could theoretically put an insulated wire link into the socket that goes onto the PCB so that it bypassed the control completely. Just be aware that the unit might not like being run for very long cycles.
Clive, have you, could you, try this on some bubble wrap? I'm curious about how well it would work,. I've seen some bubble wrap bags that I think have been sealed this way and want to replicate. Thank you
It sticks to the element if you set it too high and it's pain to get off, so don't try it. By the way, the chunkier, cast metal units can be used to seal and cut the bag at the same time, if you're fast enough.
My impulse sealer 300w failed- Please help me with Idea : the light is dead . Is it because the transformers ? How can I check this ? I bought it recently from ebay -it works 30 times. thanks
So what exactly should I swap out to increase the power to 350W- 400W? I replaced the original element with a 5mm element and it isn't getting hot enough to properly seal.
+Aurelius R I re-watched the video... I was mistaken. It actually sounds like the 1 ohm heating elements causes around 17 amps to flow through the relay(calculated at 08:00) .. At around 13:20 Clive reverse engineered the circuit and said that after the delay, power is applied to the relay to disconnect the power to the element. it sounds like the element is connected through the NC pin of the relay and once time is reached the relay latches, disconnecting the supply to the element.. I'm happy to stand corrected, although I'm not sure of any other way the relay can disconnect the supply, or what other purpose it would serve... All in all, my original comment remains, although slightly corrected, 17Amps through a little relay like that is quite impressive!
Remember that the current through the relay will be controlled by the transistor. If you had 17 Amps flowing through that transistor, even for a very small period of time, it'd definitely blow the ass end out of it.
Hi i presume the standard heating wire is 2mm wide, can i use a 5mm wide wire instead? will the transformer handle the increased width of the heating wire
@@bigclivedotcom talking about the transformer, I'm finding it's impossible to get the specs of one .. is it 220V to 18V AC? How many amps? (300VA ones would be much solid)
+rocketman221projects Its popular to use microvawe transformer rated for 800W and use it as welder where it runs at 3kW but only for one second, and transformer get only warm...
Hi Clive could I ask your opion on I want to convert a mircowave turntable from 240 volts dc to 14volts ac to replace a noter on a christmass decoration the moter failed and cant find one on the net also what parts would I nedd and a scamitic to follow love your videos always intresting and well put together thanks Ray
+Ray Campbell The microwave motor is wound entirely for the higher voltage. You'll need to source a proper low voltage motor. Keep in mind that the synchronous motors are designed for AC and will nit rotate at all on DC, so make sure you've used the correct power supply. Other than that you may be able to find the correct motor on ebay, as they are often a very standard form. But sometimes it's cheaper just to buy a while product with one inside it already.
+bigclivedotcom If he was particularly keen and he was indeed going to run it on AC, he could rewind it though, eh? Voltage proportional to number of turns squared?? I've done tedious and unjustifiable things like that before, but not specifically one of those microwave turntable motors. Typing "geared motor" into aliexpress is where it's at.
Soooo basically they are driving the crap out of the transformer ? 17 amps from that little xformer must get hot if left on too long and very dangerous.
Great video! (You mentioned the open circuit voltage you measured was 24V. Was this the transformer step-down AC voltage? or voltage AC or DC across the sealing wire?).. Hence my question here -Can you please confirm : 1) what is the step-down voltage of the transformer? 2) what is the voltage applied across the sealing wire? Thank you!
Can anyone give a link to a board etching system, that was mentioned by Clive? (cyno gs/sino gs ?) Cant hear its name properly, I googl'd every similar letter combination with no luck. Can anyone help?
I'm certain the stainless steel strip used as the heating element has a very large positive temperature coefficient. The transformer starts out putting an overload current into the heater, but the heating element gets warm/hot and its resistance increases to something less stressful for the wimpy transformer. Have you checked the load voltage across the heating element yet?
Dear clive sir, First of all thanx for such a nice vedio. I am too young to comment. I am polytechnic final yearstudent. I saw you vedio ,what a nice video full of information. Sir i have opted this as my final years project. I seek your guidance and require help from time to time. I hope you shall nit mind in repling and guiding. In your reversr engineerd circuit a no of patameters of components are required and their available market number are required Diode no . Transitor no. Value of relay or number Electolyticsl capacitir nonormally open micro switch number Zener diode no etc. Kindily provide their marketing no. It shall go in long way. Please do help. With regards
Technically it's close if anything can actually conform to the ever changing EU regulations. I'm sure there'll be some relevant regulation written by some complete plum in an office somewhere who has no actual real life technical experience.
It wouldn't be the first time I've been exposed to asbestos. The worst type isn;t the bonded version, but the loose fluffy type. Particularly blue asbestos which looks like laundry dryer fluff.
I was half joking (although it wouldn't surprise me if it was indeed). I've had the opportunity to look at asbestos-affected lung tissue in a microscope, rather interesting stuff. Here asbestos is still not uncommonly used (although due to the warm climate perhaps not as dangerously as in cold places?)
It's (in the bag sealer) most likely fibre (glass) bonded with concrete. Don't flex it too far, it will probably start falling apart. Even the Chinese wouldn't be so stupid as to be using asbestos. Would they? Really? I know (knew) an electrician who got mesothelioma. He'd only ever worked in one place where there was definitely loose asbestos fibre - on a ship where all the pipes had just been lagged with asbestos during a refit. He was a radio tech, and was doing an antenna installation at the time. :-( Thankfully all the ships old enough to have steam pipes or hot water pipes lagged with asbestos are now scrap, but it's something to keep in mind if you get asked to do a job on an old clunker...
Got one of these for cheap through a liquidation sale at a closing retail store. Never knew how much I needed one of these til I got one.
Thanks, Big Clive! You are the Best.
Just bought one of these on EBay, and then saw your video - neat!
I believe the capacitor across the relay terminals is to stabilize the holding current. The current available from the resistive dropper is going to be extremely limited, and since it is half-wave rectified, that relay will tend to buzz. Certainly not something you want to risk happening when it's controlling the inductive transformer across mains.
Very informative & helpful video, in future I will search out your other videos.
Was it an impulse buy..
+Brian Wall
Pun intended ?
+Azzy M of course
Brian Wall ;-)
I think you could replace the teflon sheet with some doubled over kapton tape.
I have been using one of these for years, it hasn't failed me yet but the power connector on mine is like a crap midi connector.
i have been watching a lot of your videos lately, and they are great, i feel like i have learned very much (especially about LEDs) from you tearing down electrical items and showing us how they work, in fact i like that poundland items and cheap chinese things are the stuff you get, because often they seem simple enough that it would be possible for me to make my own version or use a particular trick they use in something i want to build.
anyway, keep up the good work :)
***** The Poundland stuff is just perfect for hacking and modifying. You wouldn't believe how many bits of their products end up incorporated into the props and sets of TV and film productions. And if you mess something up it only costs a pound to replace, so you can have another go.
I used to work with an industrial one of these, bagging up 40-lb sacks of fertilizer. Needless to say, it gets very dramatic (and smelly) when the heating element breaks. It arced and burned right through the Teflon.
150W for the element and 150W in the transformer. Typically a 56VAC open circuit transformer, run horribly overloaded. I fix them all the time, but this one is the nastiest I have seen, the ones I buy are the metal cased versions, a little more but survive production use. Tape I buy in 2 sizes by the roll. Timer I always mod by adding a VDR across the relay contacts and adding a 220k resistor across the 2 wires to the pot so the max time is 4 seconds. Saves the element burning when time is turned too far. That timer board is the bad version, the ones I use have a SCR ( I use a C106D as a replacement) as the relay drive, and they are a lot more consistent in operation. Relays are luckily a part I can get for $1, and I use a lot of them. The cap across your relay coil is to prevent chattering of the relay as it pulls in, which will kill it very fast.
I wonder how many of those red stanley screwdrivers have been sold in the last 70 years! I'm sure my Granddad had one!
Seeing this delay design circuit basically one also can put a 555 module laying around tuned with a good solid state relay and add a batteries or supercaps or a power supply and that's it! Thank you for saving me the money and time buying and reverse engineering this!
The heat strip is probably a ribbon of nickel-chromium metal. Ni-chrome is in common usage as a heating element and also as a heated 'cheese cutter' for plastic foams.
The impulse sealer I had used a self-adhesive white 'cloth' covering the element. When I had to replace it, the dealership had a newer Teflon self-adhesive strip as well as the original clothy type. (technology moves on.)
One reason these have become so cheap is because the 'technology' in them is primitive. Just a nichrome strip under Teflon with a timer module.
The one I had, (my brother has it now,) used more industrial components.
(See the RS Components line of sealers.)
There are models with cast iron chassis; it seems like paying slightly more than plastic ones is worth it if you're planning to use it a lot -- such as in kit manufacturing or component wholesale job.
Great video, went from such an easy product of sealing plastic bags to a mind bender trying to figure out all the math for a simple circuit. I was trying to follow along with the math I know of automotive DC circuits, but got stumped on how long the capacitors take to charge and then what voltage it would be to pass the last zener.
I bought one of these recently. There's been a few updates to the design: slightly less dodgy switch arrangement, screws at both ends of the element, slightly changed timer circuit (some values changed), potentiometer soldered directly to pcb. I modified mine by increasing the resistance of the timing resistor because at the maximum setting it wasn't quite as long as I wanted for some of the thickest foil bags I tried.
David Robertson Seems like a competing or older product, especially with the screw instead of a hook at the back.
I love these, I got a 12" one and it was fabulously dangerous when I bought it! Since fixed!
I think that element might be more likely nickel chromium heating element wire. It's a lot more stable than steel, even stainless. You can't tell I've taken a few things to bits myself can you?
We use the same ideal to change rolls in packing cases where I work. We take the almost end of the roll to the almost beginning of the next roll.
I love my impulse heat sealer. Great for bagging parts each in their own section of a single packet. Put first lot of parts in, seal, second lot of parts, seal, etc.
It is worth pulling the bottom plate off the unit when you buy to make sure the wiring is tidy and ensure the cut-out PCB and spade connectors are secured properly.
I got mine on eBay and it didn't work on arrival due to one of the spade connectors popping off. 2 minutes work and it was sorted.
DavidAVD1 I got a load of the metallised anti-static bags to pack some new kits in. It will actually be much nicer than a stapler for that.
I have one myself which sat new in the box for ten years or more, also made in China, but much better made than this one. For one thing, the housing is a proper magnesium alloy casting. Also, the transformer is quite substantial, even when you consider that my unit is a 300w version. When I bought it from the person who ordered it through the mail ($5 from her yard sale), it did have a bit of shipping damage in the form of a small chip in the housing and a broken fuse holder. The only problem I found with the unit was that it didn't come with a grounding cord; I quickly rectified that, using one of the pillars cast into the housing as a grounding point.
at 9:51.. stylish perforated air holes ' probably to let the smoke out from the transformer'.. 😁😁😁😁😁 You crack me up Clive!
I have one of these. In a tan metal enclosure (or was it pale blue...) instead of your blue enclosure. I've used it to seal up a few things for eBay sales. You can get shrink bags, seal it with this thing, then use a heat gun or hair dryer to shrink the bags.
I'm in North America, so 120VAC power. (No idea what the circuitry in mine looks like.)
goes to show that cheaply made stuff doesnt have to be crappy and dangerous
also seeing how simple it is idk why they use to be so expensive itd be interesting to see inside one of the old expensive ones to see if there was anything fundamentally different about them
These used to be popular for sealing in medical applications, everything in that sector gets a giant markup because it does. We had to replace these with fancier units as the business was swallowed up by larger companies, and validation requirements got more formal.
Oh look, it's a LEFAD.... Light emitting flyback avalanche diode.
This is top notch engineering :-)
Oh and that cap across the relay coil looks to me like it is for stopping the relay from becoming an astable buzzer.
Those poly bagging machines that do frozen veggies have the same kind components. The jaw that seals the bag has 2 nichrome strips and a wire that cuts the bag. Refrigerated water goes through the jaw so it seals instantly. The nichrome strip on top seals the next bag to be filled, the one on the bottom seals the filled bag at the same time. After the bags are sealed the wire between them cuts the bag then the jaws open the bag falls off the teflon cloth strips. The wires went to solid state relays then a I/O board.
You can use them for heat sealing plastic cosmetics tubes as well. Did that one have a proper plug on it or the crappy 3 pin with no fuse in it like the one I took off mine?
LOL @ fused plugs on chinese equipment.
Very useful video thankyou, as I was planning on buying one of these on ebay for sealing the foiled anti-staic bags :)
Hi. Great informative video. Can I ask, can the element on a machine like this be replaced with a larger/wider one so it can make a wider seal in the plastic? Many thanks
I'm afraid not. That would require a matching transformer for the much higher load.
Ty for your video, I've been meaning to get one of these but didn't know their cheap name :D I got one on order for an earth shattering $25 (about the same size as yours), don't have a use for it right this moment heh heh heh, but will come in handy for when I get around to playing with my Ammonium Persulphate (the tree hugger version of ferric chloride that we're all forced to use these days here in her majesties cotton wool convict colony) and dividing it up into smaller portions to better manage it's extremely hygroscopic nature.
Unlike Ferric Chloride it's clear, which is kinda handy, but apparently can let off fumes (never noticed them) only problem is, it's far far far more temperature sensitive than Ferric Chloride, it's dead as a post at 20C, kinda sorta works at 30C but is much better at 40-50C........
The transformer probably has magnetic shunts to limit the o/p current, similar to an arc welder or microwave transformer.
Couldnt quite see the trans in the vid, but it looks like all the e's and i's are inline, this will have been done to increase stray fields, another trick to limit saturation done in the above mentioned trans's.
The capacitor across the relay may be a delay before the relay releases to prevent re operation until the main cap discharges so the next operation gets the full time period
+Sparky Projects Either that, or it resists the sudden voltage spike when the relay turns on. The diode will prevent the back-EMF, but when the coil is energized it could cause a spike, and/or dip in the supply rail, which the cap might help mitigate?
A disappointing lack of sealing means it might not be so safe for kitchen use, but then for the price point I'm not terribly surprised. I suppose one could silicone the base up, since presumably the vent holes aren't really doing much?
BenjaminGoose But it has big open mechanical holes on top. Sealing the bottom will just fill it with spilled liquid, making it much worse.
For ESD bags, a nice thing to do is make a small dent on the side under the seal so they tear down easily and predictably.
So is this the product to use when you suddenly want to seal something?
That Guy I guess
I was thinking about something like a bag of chips
Love your accent!!!
Dude. this video is great for my purposes. Thanks!
if you increase the heat, and while sealing , just pull the bag away it will c ut and seal at the same time.
The wire is nichrome and the strip is silicone Laddie Dave Sealer Supply www.sealersupply.com
nichrome is too expensive for this :)
Another enjoyable video .
Do you know if that tubing would be safe for food use - not liquids, just things like cakes or salad etc
You get food grade versions. More sterile manufacturing.
Does the unit seem reliable?
Does the timer circuit seem reliable too?
Thanks
Lou
Hey Clive. Long time viewer, first time commenter. Firstly, I love your videos; they're so real-life and informative (especially find the decriptions of the circuit diagrams useful, yet baffling at my particularly amateur stage) that I decided to go out and get my own soldering kit, multimeter and basic electronics kit and enjoying it so far, so thank you for that.
A question I do have about this video is about the two resistors in parallel. Why would it be beneficial so put 2 10k resistors in parallel and get less resistance when they could have just used a 5k? Is it because if one fails it protects the circuit? Anyway, hope you're well and the weather's treating you better in the Isle of Man than it is in Wiltshire!
+Stephen Turley Two resistors in parallel will handle twice as much current, so maybe they were exceeding the power rating of a single small resistor.
+Stephen Turley the resistor are usually rated for how much heat they can dissipate 1/4 watt 1/2 watt etc. the 2 10ks in parallel wouldn't get as hot as a single 5k with the same rating and resistors also get bigger the more heat they can dissipate so it may not have fit or it could be cheaper to use two 1/2w 10kohm then one 1w 5kohm resistor
i have electronics sourcing experience in a manufacturing plant. using 2 pcs of lower wattage is less expensive, why because low watt resistors are more common and therefore less expensive and more easily sourced. that is the major reason for choosing 2 pcs instead of 1 large wattage. electrically 2 pcs carries higher current.
2 resistors dissipate more
Thank you. Simple but interesting to know.
ah...this ones familiar. Had to use them to seal bags at the food bank when our class did volunteer work there. So many pearl onions...the smell...it somehow permeated the rubber gloves we had to wear.... I hate onions so much
Thank you for your video, I'm on plans to put together a sealant material I have at home, resistance buy it. The voltage is applied to the ends of the heating resistance? 14V ac?
Can I use it to stop my wife impulse buying?
+Gribbo9999 --> Can I use it to stop *_myself_* from impulse buying? LOL ;)
Hi Big Clive, thanks so much for the video, it was so helpful in understanding a heat sealer. I'm trying to remove the timing function on my impulse heat sealer so that I can heat a seal for as long as I press down on the sealer, but I'm not very well versed in circuits (only took one electrical engineering class in college). What would you do to get rid of the timing feature completely? Thanks in advance, and keep doing your videos!
+Diyi Zhu You could theoretically put an insulated wire link into the socket that goes onto the PCB so that it bypassed the control completely. Just be aware that the unit might not like being run for very long cycles.
Greetings, I have a non electronic question. Is the plastic case molded with glass fibers?
Clive how is it impulse? Stored energy and dumped in a fraction of a second
Used to maintain an industrial version for sealing pork joints in Belcher's Prestwick
it's much the same as how a vacpack seals with the tape and all that tape can give some trouble believe me
Clive, have you, could you, try this on some bubble wrap? I'm curious about how well it would work,. I've seen some bubble wrap bags that I think have been sealed this way and want to replicate. Thank you
I'm not at my workshop at the moment, but I'll keep that in mind for when I get back.
no worries. can be used for bubble bags. i have tried.
It sticks to the element if you set it too high and it's pain to get off, so don't try it.
By the way, the chunkier, cast metal units can be used to seal and cut the bag at the same time, if you're fast enough.
My impulse sealer 300w failed- Please help me with Idea : the light is dead . Is it because the transformers ? How can I check this ? I bought it recently from ebay -it works 30 times. thanks
Thanks Clive. This will come in handy. :)
the element is probably nicrome or kanthal
if it gets stuck to magnets it's Kanthal. Cheaper too.
So what exactly should I swap out to increase the power to 350W- 400W? I replaced the original element with a 5mm element and it isn't getting hot enough to properly seal.
Check the connections and make sure it's the correct element.
@@bigclivedotcom the original element was only 2mm so the resistance of this one is higher. Can I swap out resistors for a lower value higher wattage?
@@phreaktor I'd recommend getting the correct size element. A different one could damage the circuitry.
The electrolytic across the coil gives a higher firing current which does the same thing essentially as a starter cap on an electric motor.
Hi there who supplies the Teflon strip in South Africa
Do you hqave any infomation on the relay? 7A is quite a-lot of current to stick over that slightly piss'ant relay....
+TornTech Why on earth do you think 7A is flowing through the relay?
+Aurelius R I can't remember now. Pretty sure Clive said somthing about high current during his calculations.
+Aurelius R I re-watched the video... I was mistaken. It actually sounds like the 1 ohm heating elements causes around 17 amps to flow through the relay(calculated at 08:00) .. At around 13:20 Clive reverse engineered the circuit and said that after the delay, power is applied to the relay to disconnect the power to the element. it sounds like the element is connected through the NC pin of the relay and once time is reached the relay latches, disconnecting the supply to the element.. I'm happy to stand corrected, although I'm not sure of any other way the relay can disconnect the supply, or what other purpose it would serve...
All in all, my original comment remains, although slightly corrected, 17Amps through a little relay like that is quite impressive!
Remember that the current through the relay will be controlled by the transistor. If you had 17 Amps flowing through that transistor, even for a very small period of time, it'd definitely blow the ass end out of it.
+Aurelius R the transistor is there to drive the coil of the relay not the heating element.
Thank you sir
I am sure you know by now but it's most likely a Nickel Chromium, Nichrome, (NiCr) wire. Good video. Thank You...
I use mine to seal jack daniels into bags to smuggle on cruises.
Hi i presume the standard heating wire is 2mm wide, can i use a 5mm wide wire instead? will the transformer handle the increased width of the heating wire
That would overload an already pushed transformer.
@@bigclivedotcom talking about the transformer, I'm finding it's impossible to get the specs of one .. is it 220V to 18V AC? How many amps? (300VA ones would be much solid)
can you just swap out the 2mm sealing element with a wider one?
A wider one will have a lower resistance and may damage the transformer.
That little transformer must really be overloaded. I would strap a thermal cutoff switch on the transformer so it doesn't burn out.
+rocketman221projects
Its popular to use microvawe transformer rated for 800W and use it as welder where it runs at 3kW but only for one second, and transformer get only warm...
+Arek R. Yes, and if you run it too long, the primary will catch on fire. A thermal switch would shut it off before that happens.
Timer and display will be controlled by IC so I will add thermal monitoring, for primary and secondary.
5:45 that's probably just an insulator to protect the case from the heat and the electricity
I have something similar to this. I like to reseal food stuffs so it doesn't go stale. . xD
Good video
Hi Clive could I ask your opion on I want to convert a mircowave turntable from 240 volts dc to 14volts ac to replace a noter on a christmass decoration the moter failed and cant find one on the net also what parts would I nedd and a scamitic to follow love your videos always intresting and well put together thanks Ray
+Ray Campbell The microwave motor is wound entirely for the higher voltage. You'll need to source a proper low voltage motor. Keep in mind that the synchronous motors are designed for AC and will nit rotate at all on DC, so make sure you've used the correct power supply. Other than that you may be able to find the correct motor on ebay, as they are often a very standard form. But sometimes it's cheaper just to buy a while product with one inside it already.
+bigclivedotcom If he was particularly keen and he was indeed going to run it on AC, he could rewind it though, eh? Voltage proportional to number of turns squared??
I've done tedious and unjustifiable things like that before, but not specifically one of those microwave turntable motors.
Typing "geared motor" into aliexpress is where it's at.
thanks sir,very useful video
clive where do you sell your kits from buddy i want to practice on some pcb,s do you have a website ?
The bigclivedotcom sticker that is always in view in almost every video might be a clue ;)
Thanks and Good effort
Hello where do I get the 10 mm width sealing wire?
You can get replacement sealing components on eBay.
Hi, Clive! What are the parameters of the transformer?
buy one :) you can't find specs for these cheap things anywhere. Alibaba is proud they're made out of copper LOL
Can you please link me to the sleeving? I cant seem to find any when I search for it
+IllNotBeLegit Search ebay for layflat tubing.
Never let the smoke out!
Soooo basically they are driving the crap out of the transformer ? 17 amps from that little xformer must get hot if left on too long and very dangerous.
The duty cycle is low. I'm not sure it would fare too well in a production environment.
@@bigclivedotcom : Clive do you have any idea has to what this xformer actually is rated at ?
@@packratswhatif.3990 I'm not sure. I'm used to continuously rated transformers.
Great video!
(You mentioned the open circuit voltage you measured was 24V. Was this the transformer step-down AC voltage? or voltage AC or DC across the sealing wire?)..
Hence my question here -Can you please confirm :
1) what is the step-down voltage of the transformer?
2) what is the voltage applied across the sealing wire?
Thank you!
@@SS-pi2yi Should be 18VDC going to 24VDC half wave rectified ending up on the nickel chrome wire serving as the heating element.
Can anyone give a link to a board etching system, that was mentioned by Clive? (cyno gs/sino gs ?) Cant hear its name properly, I googl'd every similar letter combination with no luck. Can anyone help?
It seems to be seno gs : www.rapidonline.com/mega-electronics-600-017-seno-sn3300-etch-in-bag-34-0385
Richard Law Thank you very much! At last, my mind can rest now )
I'm certain the stainless steel strip used as the heating element has a very large positive temperature coefficient. The transformer starts out putting an overload current into the heater, but the heating element gets warm/hot and its resistance increases to something less stressful for the wimpy transformer. Have you checked the load voltage across the heating element yet?
это цена?
9:57 LOL :D
Yours is not a name I would have expected on an electronics teardown channel.
IKR
what is it he's referring to when he says "the mains"?
+Matt Valcarcel The main power / electricity coming in. In the UK, 220 volts, 50 cycle AC.
he's referring to the 240v ac straight from the plug I can't explain it very good aha
The electricity you get from the wall socket. Is called mains electricity over in this part of the world.
In this episode, Clive learns how to seal drug bags.
China + Heating elements + What looks like tile = Asbestos..
Dear clive sir,
First of all thanx for such a nice vedio.
I am too young to comment. I am polytechnic final yearstudent.
I saw you vedio ,what a nice video full of information. Sir i have opted this as my final years project.
I seek your guidance and require help from time to time. I hope you shall nit mind in repling and guiding.
In your reversr engineerd circuit a no of patameters of components are required and their available market number are required
Diode no .
Transitor no.
Value of relay or number
Electolyticsl capacitir nonormally open micro switch number
Zener diode no etc.
Kindily provide their marketing no.
It shall go in long way.
Please do help.
With regards
Hey Clive. Do you buy anything that doesn't have a china export sticker. Or is it like the rest of us where everything is made in China nowadays.
i my hot dogs with this one at a time and leave enough to cut if i only want one works great
Is it conform to EU-regulations?
Technically it's close if anything can actually conform to the ever changing EU regulations. I'm sure there'll be some relevant regulation written by some complete plum in an office somewhere who has no actual real life technical experience.
I = V / R
that is totally asbestos, RIP Clive.
It wouldn't be the first time I've been exposed to asbestos. The worst type isn;t the bonded version, but the loose fluffy type. Particularly blue asbestos which looks like laundry dryer fluff.
I was half joking (although it wouldn't surprise me if it was indeed). I've had the opportunity to look at asbestos-affected lung tissue in a microscope, rather interesting stuff. Here asbestos is still not uncommonly used (although due to the warm climate perhaps not as dangerously as in cold places?)
Lucas de Almeida everything on the internet is exponentially more deadly then in real life Clive. Didn't you know that
It's (in the bag sealer) most likely fibre (glass) bonded with concrete. Don't flex it too far, it will probably start falling apart. Even the Chinese wouldn't be so stupid as to be using asbestos. Would they? Really?
I know (knew) an electrician who got mesothelioma. He'd only ever worked in one place where there was definitely loose asbestos fibre - on a ship where all the pipes had just been lagged with asbestos during a refit. He was a radio tech, and was doing an antenna installation at the time. :-(
Thankfully all the ships old enough to have steam pipes or hot water pipes lagged with asbestos are now scrap, but it's something to keep in mind if you get asked to do a job on an old clunker...
Clive your engineering is quite flaky.