The transistor is a microwave oscillator. When you move the microwave bounces back to the oscillator and has a doppler shift. The transmitted and reflected signal mix together to create a new frequency just like the mixer in a standard broadcast radio receiver. The difference is the broadcast radio uses an internal oscillator that's 10.7 mhz higher than the radio station and mixes it with the radio station to get an If frequency of 10.7 mhz. Since the microwave emitter and the reflected signal are the ones being mixed, the IF frequency will be the frequency difference of the reflected signal, something in the low hz range (1 to 20 hz probably). The IF at this point is simply sent through a class c amplifier to get an amplified signal that's rectified. Look up "heterodyne radio" for more info.
Clive, you are brilliant, sir. Thank you for sharing your absolute wealth of knowledge with us. I feel incredibly fortunate to have found you (entirely by accident, I might add) so that I could enjoy your videos. Not only have you helped to make me a smarter person, but you've really ignited a fascination in me for engineering in general. You are, without a doubt, an absolute gem. Thank you =)
I love it, because if you buy via paypal on ebay all you need to do is take a photo of your power meter showing that their "5W" bulb is barely 2.5W and you can ask for a partial or full refund due to an inaccurate listing. I get most of my LED bulbs at a steep discount and just order for twice the wattage I actually need. Incidentally, when I ordered a 5W version of these radar sensor bulbs, it actually WAS the claimed 5W. Shocked the hell out of me. :)
For some insight into the 1 transistor microwave part, look for "microwaves in a mustard tin", there was an old PW article. I'm guessing that there may be two antenna tracks, the second laid out to collect a small coupling from the first to mix with reflected signal
Doppler microwave detectors were The Thing in security detection at one time, years before PIRs came along. But their ability to see through wood, glass and plastic, plus the way the signal could be reflected caused problems. One particular problem we had was a detector in a locked stockroom going off at around the same times every so often. Turned out to be the night security guard using the toilet on the floor above while on his rounds - the PVC soil pipe from it went though the stockroom. Easily dealt with by wrapping the pipe in aluminium foil.
+BoboTheEpic Took a bit of inspiration - not on my part - to figure it out. As for reflections, we had a problem with one in a workshop that would sometimes alarm early in the morning. Turned out the microwave was seeing vehicles using the shared access alongside the building, but only if they'd parked their van inside and at angle which reflected the 'beam' out the side of the building. Sometimes they did, sometimes they didn't.
Very true, rodents, water in PVC and just about any moving mass will do it. The algorithms help but the only way is the dual tech combo with RADAR/PIR for anti falsing. They both have their shortcomings but when combined it's almost 100% reliable.
+bigclivedotcom from the ultra simplicity of the detection circuit I doubt these are using the doppler effect at all. Much more likely they are simply seeing the effects of a moving body causing substantial variation in the standing waves set up in the area by the multiple reflections of the 12cm waves. In effect the unit is just measuring the small variations in the apparent impedance of its antenna as the outgoing rf signal mixes with received reflections. My main worry with these units is what effect the may have on the performance of wifi in the area - the presence of considerable rf carrier, even if not on a wifi channel can causing blocking effects in the receiver circuitry, causing substantial loss of rf sensitivity and/or high error rates in decoding.
Hi Clive. Wondering if you knew of the new Poundworld LED bulbs by ITP Imports? I've got an E14 5W (40W equivalent) from there. Had it on for about an hour and it was quite warm. Just split it apart and it looks better than the Poundland Electrek (I think that's the correct name) LED bulbs. The LED PCB has a small aluminium plate underneath it for the heat sinking, unlike the Poundland ones. Thought it might be of interest for you in case you want to do a video on them :)
actually- are you sure these are actually detecting doppler shift - are they actually detecting frequency changes, or do they just watch for sudden changes in the reflected POWER of whatever rough frequency the antenna receives, when a big water-filled human walks nearby? Seems like it would be a lot simpler to detect amplitude changes over time than to finely match an oscillator and that pcb track rectenna to look for little frequency changes that might be coming from background sources anyway?
Probably not doppler, and not even radar. [edit: Maybe just the "Rad" part of radar (detection but not ranging)] In the last video he said that one used the same chip as an IR sensor. [edit: sort of like a far-field metal detector but it sensing the RF reflections]
+Mike Guitar You may be right. If it's Doppler there'll be some kind of pulse counting after the amplifier. Without it it's going to be a simple field change. [Edit] The pulse counter can be a simple diode pump arrangement.
RF doppler detector technology has been around since WW2, where it was used in the "Variable Time" (VT) or proximity fuze for artillery shells. A simple RF oscillator and tone detector would detect the reflection of radio waves from enemy aircraft, and fire a detonator to explode the shell when within lethal range of the aircraft. All this was done using tiny vacuum tubes which were rugged enough to withstand the shock and acceleration of being fired from a gun barrel., and cheap enough to be used in this type of "disposable" single use application.
One of the "secret weapons" on the Allied side. Definitely made the ships in picket formation more effective against Kamikaze runs than they otherwise would have been.
This is quite amazing. doppler radar used to be the way to do a lot of the things that we now do with PIR - intruder detection, commercial automatic door openers and I thought PIR won the tech battle by very quickly getting cheaper and more mass producible than radar. Many years ago Maplin used to sell a pair of quite sizeable (20 cigarette packet size I think) doppler radar transducers TX&RX for IIRC £20ish each or a thing called a Gunn diode if you wanted to roll your own. I think the real killer app for these would be energy saving office & industrial lighting control systems, I used to work in an office with a lot of PIR nipples in the ceiling which would switch off the lights if they didn't detect movement for a few minutes... but the problem was PIR can't see through cubicle walls. If energy saving triggered you had to actually stand up and walk out of your cubicle to get the lights back on again.
Thanks Aaron, it's not a problem for me any more since I no longer work there but it was a ceiling nipple like one of those - seems their products are based on PIR or ultrasound (or both combined) ultrasound is another technology that I thought PIR had replaced tbh it used to suffer a lot of false triggers and jamming from unexpected ultrasound sources IIRC- I'm not sure how it would have coped with the sound absorbing panels my cubicle was made of... but afaik a lot of surface can have surprising acoustic properties at ultrasound frequency. seems to me PIR could be quite complimentary to ultrasound or Doppler radar since afaik PIR is most sensitive to tangential movement wrt the sensor and the others are most sensitive to radial movement.
Where do you find these? I've tried to look on Amazon and can't find them. Would like to get a few for the bathrooms. Right now I'm using mostly "TCP LA1027KND6" Bulbs.
Clive, you may not notice an effect in a box but it is very possible they could interfere with other equipment While cool, this LED looks about as EMC compliant as the last doppler one. I all but guarantee they don't meet emissions standards for anywhere using CISPR.
Could I measure speed with one of these? I'm from the US and there is a company that sells a device they call the Doppler for a very expensive price. I've never been able to get my hands on one but I believe that they are using a chip like this to mark the time that a bullet is detected passing the device until the bullet can no longer be detected by the device and has gone out of range since the sensitivity of these little boards can be changed. The only other thing that this expensive device does is keeps up with the number of rounds shot and their speed, give averages, store data and also give a bullet coefficient; to give the shooter the speed that their bullet is going, the amount of energy that the bullet would hit an object and different ranges. You put the data into the device; like the weight of your bullet, type of powder you are using and the length of your barrel and it gives the information based on the time it took the bullet to pass the device once it is fired. As I mentioned this Doppler system cost lots of money and has American shooters who can afford the device buying them so much that they are alway out of stock. There has to be a better cheaper way. I don't see why all of this couldn't be done wit ha Pi or even an Adriano and have even more capabilities. We still have companies charging hundreds of dollars to have a camera near a stationary target so that the shooter can see their hits on a stationary target and companies are marketing it like it's the best thing to hit the market for shooters. I have noticed that there are some channels where makers and quad flyers have started to visit and getting on the firearms channels and debunking the cost of these products and showing what they have been doing with cameras on quads for at least the past 10-15 years and the distances that they can send a moving video signal using a camera that fits in the palm of your hand and can move and focus while in the air. The one people who buy these devices now are the uninformed and those who want to be the first or show the money they have; like I said, a person could build one of these devices in a couple hours, now around $15 with moving cameras using a joystick. Some of the products are just plastic ammo cans with a hole cut in it where the camera poked out; which you pointed the camera at your static target, made sure that it all lined up on your tablet before moving back to shoot and these products sold/sellsfor 400-500 dollars still. The ammo can holds the camera, battery, relay board, and antenna that sends the video signal back to an ipad, tab, or phone that the shooter has from where they are shooting and you have WiFi where the shooter was at for the systems to work; some of the devices couldn't even send a clear video signal more than 200 meters or so and the majority of them had to be in direct line of site of the tablet. The devices were so antiquated that they couldn't move the camera in the box unless you manually walked to the box and physically moved the box to the position you wanted it in. For a few years, devices like this sold between $600-1000 US dollars and maybe cost $30 dollars to make out of Quad FPV parts. Shooters were buying these products and showing them off as new space age technology that would help with a person;'s shooting.
I find these fascinating too. Bought several different modules to play with. Currently moving house but will get them out when that is done. I wonder what magic can be done with wave guides, reflectors/shields and absorbent materials.
Hey clive, try taking the antenna track at the end of it and scrape just a little bit of the trace off at a time and see if it affects your range and sensitivity.
I suspect that my apartment is too small for this to be effective. My computer is directly under my bathroom, so it would probably turn on every time I get up for a cup of coffee.
RADAR is cheaper than a PIR chip, but has it's drawbacks of falsing. I wonder how this bulb functions with a ceiling fan, water thru PVC pipes. Expensive ones for alarms use algorithms for falsing and constant repetitive movements and of course combine PIR and RADAR for reliable anti falsing in alarms.
+bigclivedotcom Have you seen the led lamps that supposedly do PIR and sound detection? e.g. 'Sound Sensor Auto PIR Motion Detection LED Bulb' Do they actually detect either IR or sound, and if so, what circuitry do they use? Or is it really just a sound detection circuit with the buzz-word 'PIR' added to the description? Just curious how these work.
These would be awesome in a shed or garage down the garden, I use one in my hallway as the switch is several feet away from the door when coming in at night! Would be a great way of silencing those noisy bathroom pull switches in the middle of the night too!
Widely reported that this is 2.4GHz, antenna looks to be about right from the video and 2.4 GHz is an unlicensed ISM band for much of the world so it is likely 2.4GHz. This is well above radio range, also outside mobile (cell) phone bands (could be spurious emissions). Wi-Fi and Bluetooth operate in the 2.4 GHz ISM band. There is potential for these to interfere. WiFi and Bluetooth has some redundancy against interference and the transmitting power looks to be too small to desensitise the receiver so I doubt it would have a noticeable impact. that being said, if you live in a developed country or major developing country than chances are this LED (like much of the items on Big Clive from Ebay) this would not comply with emissions profiles due to harmonics, spirious emissions and the general poor performance of many of these LED drivers with lack of RF suppression
If this is running on 2.5ghz does that mean it could interfere with wifi and phones? Also isnt the proliferation of radio noise a problem? :p I mean, have a load of these around the house could cause all sorts of problems couldnt it?
If it operates on 2.4 Ghz it will likely interfere with wireless networks wont it? What power does it output on the antenna? Besides that it is amazing that this radar is implemented in a very simple way. I only heard of that technology as part of expensive security systems.
one of my side hobbies is radio, now i dont pretend to know how a uWave tranciever works, it must change between a send and receive state or the transmitter would over power the receiver being so close to each other. I have seen a very similar configuration in a wireless router where the copper tracks on a pcb form the antenna, and yes you are right, in transmission, the antenna length is crucial for the swr to be as close to 0 as possible (swr is the amount of energy fed back down the transmitting antenna to the transmitter during transmission, bit of a mouthful and a bit more complicated than that but..) for 2.4Ghz the length of a "perfect antenna" would be 6cm, but for compromise usually a 1/4 or 1/2 or 5/8 wavelength is used at the expense of power output. Im wondering if these bulbs use a more capacitive approach, much like changing the tone/volume on a theramin in relation to proximity of your hand to the antenna's on the instrument ???? Guess what im trying to say is, the tracks are part of the tuning circuit for the 2.4Ghz square/sine wave carrier. You or another grounded object (tree) getting within the field of the tracks will cause the tuning to shift and maybe this is what the chip is looking at, a noticable drift or shift from its normal referenced frequency ??
Aren't there ones that have adjustable range/power or whatever. (Or better yet which use waves that don't go through thick walls.) I ordered some PIR ones, but I got a bit screwed, because I didn't think that light fixtures don't transmit thermal infrared radiation. (Apparently neither glass, nor plastic.)
I picked one of these up after watching the video and put it on my back porch. seemed to work fine at first but... temps dropped down to 40f that night and you'd have to wave your hand right in front of it to get it to come on. then it'd warm up from running the LEDs and it'd work fine until it cooled off again. pish.
As you say, it's entirely possible that having multiples of these would cause them to trigger off each other or just on ambient EMI from other electronics in your house. e.g. turning on your TV or computer or whatever and suddenly all the lights in the house get triggered.
False triggering was one of the banes of Microwave security sensors "back in the day". They were better than Ultrasound, but the improvement in falsing vs. the cost was very poor. That was in the day of the IMPATT diode; I believe the introduction of the GUNN type microwave diode reduced costs, and led to a resurgence in "affordable microwave Doppler" security systems?
I bought some of these because of your last video. Turns out unfortunately that the will trigger each other. As amazing as they are black magic-wise, I'm having difficulty figuring out an application for them, they just see too much.
If you had one of these in a multi story house would it detect movement on different floors? I ask this as I live in a high set house with a garage/workshop/laundry on the ground floor. This sort of bulb would be great but not if it kept detecting movement in the living area.
Maybe it would work better as an alarm for people, or maybe wind if you need to put umbrella's down or some other early warning device other than a light.
I like the premise of these lamps, but as someone who is getting into amateur radio, I'm sure that those things spewing RF about that place would cause some trouble...
Hi! In what way you dim your foodlights at 2:10? (I remember you saying earlier that you have floodlights installed) I've wanted to get a 30W ceiling-aimed floodling to illuminate my room with soft, ~homogeneous diffuse light, but unfortunately they don't make dimmable ones...
i should add that to wash your room with a soft ambient glow, simply bounce the lights off the ceiling instead of having them aim directly down. Basically using them as an uplighter.
bigclivedotcom "I'm actually adjusting the camera exposure at that point." Ah, okay. Didn't think of that. Silly me... "simply bounce the lights off the ceiling" That's precisely what I want to do! :) Just have to figure out a way for dimming.
I got 4 doppler radar units in a box from AliExpress, each had 5 leads. I had to look inside to figure out how to wire it. I saw a solder bridge on it's radar loop antenna, before removing it I looked at another one and it had a solder bridge in the same exact place. OK, turn off the iron.
Is there way to "limit" its sensor range in way that its eg. sense movement only in specific spot(eg. just one side of lamp where are doors, not window) by shielding that antenna or whole lamp by some material? Of course I mean in way that it would be easy and cheap like small metal grid/net putted near, or it would need to be cooper(its used for RF shielding)? It would work or it would bounce that ""movement"" waves from other walls/object and still reach lamp?
Its probably a super heterodyne receiver circuit one transistor acting as an oscillator and a mixer. When the bounced signal mixes with the local signal there is no product and when it bounces off a moving target the difference in frequency from the oscillator then the mixer gives a product simpls.
The difference frequency is in the order of 200 Hz at an oscillator freq of 30 GHz and a target velocity of 1 m/s. I would guess it is pretty hard to detect that frequency shift with such a minimal circuit, so my bet would still be on disturbance of the amplitude of a standing wave: in-phase / out-of-phase. en.wikipedia.org/wiki/Proximity_fuze#Radio
Well that's definitely a new idea for lamps. Can't wait till people find out that it's emitting microwaves constantly into the room. I can hear them all bitchin about their headaches already ! Very Cool .....
It's an issue with the light sensor being lit by the light itself. The usual fix in other equipment is a diode that makes it think it's dark while the light is on.
Clive, Perhaps its switching between tx then rx to catch the reflected energy?, and chip counts the tx to receved time and triggers if below a certain value. Like an electronic tape measure perhaps?
zx8401ztv Pulsed Doppler seems feasible- the system isn't just looking at reflected energy (actually re-radiated, but that's a whole different discussion), as Clive says it looks for the frequency shift. That effect you get when a vehicle with a siren goes by, as it approaches the sound waves are essentially squeezed closer together (frequency goes up), and as it goes away the waves are stretched out (frequency drops). RADAR doppler works in the same way. You transmit a pulse (the pulse width determines the minimum range of the radar) of a set frequency and then wait (the wait time determines the maximum range of the radar). You get a 'return', the time taken (div/2) is the range, and the Doppler 'shift' (frequency change) gives speed (+ve (approaching), the same (same speed as TX) or -ve (moving away)).
Same way as an FM decoder works - the "information" is in the "beat frequency" and this is processed by the "PIR chip" in the same way as the output from a PIR sensor. The chip "sees" a minute input voltage change, and acts accordingly.
Phil S. Ahh i see what you mean, so its not listening for the original rf, its looking for the lower beat frequencys changing from an empty room reading :-D. Thats clever and amazing that they did it with such a minimal circuit. Thanks for your discription, i dont allways see things clearly.
zx8401ztv If the room is empty or full does not matter. Movement is the important thing. even if there's ten people in the room, it would stay dark if noone moves.
Exactly, I'd love to see what shows up on WiFi Analyzer (android app). If these devices use 2.4 GHz they could end up trashing your or your neighbors WiFi.
I beg to differ, the front end of most home WiFi routers and devices is easily swamped by other 2.4 Ghz devices. A common concern is the use of 2. 4 GHz wireless telephones in the proximity of WiFi devices.
Well additional investigation (Google searches) indicate that these devices operate at 10.525 Ghz which is just above the 2.4 GHz WiFi band (2.4 to 2.4835 GHz) allocation. So depending on the relative signal strength one could conclude that they would have minimal effect on typical 2.4 Ghz WiFi devices. However if these lamps emit a signal much greater than typical WiFi devices they could cause interference. It would be interesting to monitor WiFi data throughput in the presence of these lamps.
That doppler idea seems a bit daft to me considering that if the trees outside can cause it to switch on, it'll be a waste of electricity as the lights would always be on rather than switched on when someone enters a room... :\
Hi! Did anyone see these that were also adjustable. (lightness, time, sensitivity) It should be rather easy since the bulbs have openings on them to start with. But I'm not sure if any of the sellers do it.
The Doppler ones work inside light fittings, the infrared ones do not work inside many fittings that include glass etc. The infrared ones need a direct sight whereas the doppler ones will even detect movement through walls. One is not 'better' than the other, they have different uses IMHO.
hey there fans of dark magic: i found the datasheet for the EG4002 chip that clive found in this cool little lamp. it was in chinese and i had it translated, but i'm still trying to figure out how this could be used as a doppler sensor. Any thoughts? i haven't found the patent clive mentioned, but it might not be published yet if it's been filed less than 12-18 months ago depending on the patent office. Do you guys know what company might have filed this patent?
Is there any proof this uses the 2.4Ghz band? I wouldn't want to cause interference with wireless stuff. The radar modules I have seen on ebay use 433Mhz.
The frequency will be determined by the antenna length on the PCB and I'd guess the capacitors too. It's not going to be super accurate, but it's extremely low power.
Thanks, I guess it will be hard to get a reading without temporarily messing up the tuning. I might have to get one of these used DVB-T sticks from ebay and figure out how people abuse them as software defined radio to monitor nearly the whole RF spectrum.
+ACombineSoldier I would imagine they would need some tinkering for outside use or even to use multiple of them in proximity. Depending on the sensitivity, a tree branch swaying in the wind, a small animal, or even a heavy rain could trigger these. None of those things would trigger a IR detector light.
All of these (wind, animals, rain) can trigger an IR detector. It's just a matter of sensitivity. I have a light that regularily turned on because of a tree moving in the wind in the neighbour's garden. Had to block out part of the dome because turning the sensitivity down so it would not react would also have made it almost useless. I also have an IR detector that activates a water spray when a cat tries to poop in the lawn (funny thing ;) ). It works reliably even at 5m+.
I'm thinking of adding something like this to external coach lights because it's easier than adding a separate sensor to the circuit, my house is aluminium clad, if I have these on the outside they shouldn't detect me on the inside should they?
would be interesting if a simple wire screen could stop the light from triggering it on the wall inside. like a Faraday cage would! or would it multiply the triggering?
Don't have one of these lights to test but the RF output is going to be quite low and AAMI PC69 exists to protect ICD from RF radiation from DC (0Hz) to 3 GHz although this will be expanded in future versions. I would be more worried about Wi-Fi than this little transmitter. A good article on ICD, standards and immunity is from Dr Kay www.engineersaustralia.org.au/sites/default/files/shado/Learned%20Groups/Technical%20Societies/EMC/Newsletters/newsletter_54_repaired_fot2.pdf
Higher than one would expect based upon the circuit, 115VAC? Then again, this could be from how the PIR is shunting the LED to off rather than the detection side. Hard to tell without the circuit diagram of the measured LED.
SigEpBlue the ism band just means that the end user dosent need a license. There are tons of bluetooth, wifi, etc items on the fcc redistration site for ism items.
Sorry for off topic but anyone know where I can get decent warm white LED bulbs? A local shop has 2700k ones with gorgeous output but they are very costly. All I've ordered online have been way too cold even when sold as warm white.
None of them seem to have been bothered by the neighbouring wifi signals. They're only really detecting a slight modulation of the reflection of their own frequency.
Yeah the word "reflection" can be misleading. If I walk in front of a radio the signal can change and that can be used as a proximity sensor. But this doesn't mean there's a radar system inside my radio, lol.
It depends on your application. The PIR version is going to be more accurate in detecting people inside a room, but the radar type is going to be more sensitive to small movements.
What with Phones and mast's And of course Microwaves ovens and not forgetting Smart meters I don't think we need any more microwaves even if this is so low power, after all it could be the straw.........
How about this, you can either use your microwave oven for 3 seconds less each year, or receive 1 second less direct sunlight each year to make up for this extra microwave radiation. Because radiation is all equally harmful and works JUST like the fallout games, right?
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--Clive 2016
It's my drinking game. I take a swig whenever I think Clive says something naughty.
The transistor is a microwave oscillator. When you move the microwave bounces back to the oscillator and has a doppler shift. The transmitted and reflected signal mix together to create a new frequency just like the mixer in a standard broadcast radio receiver. The difference is the broadcast radio uses an internal oscillator that's 10.7 mhz higher than the radio station and mixes it with the radio station to get an If frequency of 10.7 mhz. Since the microwave emitter and the reflected signal are the ones being mixed, the IF frequency will be the frequency difference of the reflected signal, something in the low hz range (1 to 20 hz probably). The IF at this point is simply sent through a class c amplifier to get an amplified signal that's rectified.
Look up "heterodyne radio" for more info.
Clive, you are brilliant, sir. Thank you for sharing your absolute wealth of knowledge with us. I feel incredibly fortunate to have found you (entirely by accident, I might add) so that I could enjoy your videos. Not only have you helped to make me a smarter person, but you've really ignited a fascination in me for engineering in general.
You are, without a doubt, an absolute gem.
Thank you =)
I purchased one of these bulbs made by Elrigs and it worked for about one day then just stayed on regardless of light or motion. Love the vids Clive
i find these videos really interesting because I can always find something the backs up what I've been learning at college
Chinese three watts!! it has got a whole new meaning after i started watching your videos :D
i wonder if it works for chinese inches too :P
Jonas Ö
If Clive put a larger value resistor in series with the leds, why would that be like Chinese food?
They would both be...
dim sum. ....... ;>)
these jokes are dog tired.
I love it, because if you buy via paypal on ebay all you need to do is take a photo of your power meter showing that their "5W" bulb is barely 2.5W and you can ask for a partial or full refund due to an inaccurate listing. I get most of my LED bulbs at a steep discount and just order for twice the wattage I actually need.
Incidentally, when I ordered a 5W version of these radar sensor bulbs, it actually WAS the claimed 5W. Shocked the hell out of me. :)
Stop being so catty.
For some insight into the 1 transistor microwave part, look for "microwaves in a mustard tin", there was an old PW article.
I'm guessing that there may be two antenna tracks, the second laid out to collect a small coupling from the first to mix with reflected signal
Doppler microwave detectors were The Thing in security detection at one time, years before PIRs came along. But their ability to see through wood, glass and plastic, plus the way the signal could be reflected caused problems.
One particular problem we had was a detector in a locked stockroom going off at around the same times every so often. Turned out to be the night security guard using the toilet on the floor above while on his rounds - the PVC soil pipe from it went though the stockroom.
Easily dealt with by wrapping the pipe in aluminium foil.
+BoboTheEpic Took a bit of inspiration - not on my part - to figure it out.
As for reflections, we had a problem with one in a workshop that would sometimes alarm early in the morning. Turned out the microwave was seeing vehicles using the shared access alongside the building, but only if they'd parked their van inside and at angle which reflected the 'beam' out the side of the building. Sometimes they did, sometimes they didn't.
Very true, rodents, water in PVC and just about any moving mass will do it. The algorithms help but the only way is the dual tech combo with RADAR/PIR for anti falsing. They both have their shortcomings but when combined it's almost 100% reliable.
+bigclivedotcom from the ultra simplicity of the detection circuit I doubt these are using the doppler effect at all. Much more likely they are simply seeing the effects of a moving body causing substantial variation in the standing waves set up in the area by the multiple reflections of the 12cm waves. In effect the unit is just measuring the small variations in the apparent impedance of its antenna as the outgoing rf signal mixes with received reflections.
My main worry with these units is what effect the may have on the performance of wifi in the area - the presence of considerable rf carrier, even if not on a wifi channel can causing blocking effects in the receiver circuitry, causing substantial loss of rf sensitivity and/or high error rates in decoding.
Hi Clive. Wondering if you knew of the new Poundworld LED bulbs by ITP Imports? I've got an E14 5W (40W equivalent) from there. Had it on for about an hour and it was quite warm. Just split it apart and it looks better than the Poundland Electrek (I think that's the correct name) LED bulbs. The LED PCB has a small aluminium plate underneath it for the heat sinking, unlike the Poundland ones. Thought it might be of interest for you in case you want to do a video on them :)
actually- are you sure these are actually detecting doppler shift - are they actually detecting frequency changes, or do they just watch for sudden changes in the reflected POWER of whatever rough frequency the antenna receives, when a big water-filled human walks nearby? Seems like it would be a lot simpler to detect amplitude changes over time than to finely match an oscillator and that pcb track rectenna to look for little frequency changes that might be coming from background sources anyway?
Yeah, or change in standing wave performance, or de-tuning an oscillator circuit so it stops/starts to resonate.
It'll be Doppler.
Edit: Maybe not - see my later comment.
Probably not doppler, and not even radar. [edit: Maybe just the "Rad" part of radar (detection but not ranging)] In the last video he said that one used the same chip as an IR sensor. [edit: sort of like a far-field metal detector but it sensing the RF reflections]
+Mike Guitar You may be right. If it's Doppler there'll be some kind of pulse counting after the amplifier. Without it it's going to be a simple field change.
[Edit] The pulse counter can be a simple diode pump arrangement.
Doppler looks at frequency shifts, aka "red shift" and "blue shift". It's too fast to be considered "pulse counting".
RF doppler detector technology has been around since WW2, where it was used in the "Variable Time" (VT) or proximity fuze for artillery shells.
A simple RF oscillator and tone detector would detect the reflection of radio waves from enemy aircraft, and fire a detonator to explode the shell when within lethal range of the aircraft. All this was done using tiny vacuum tubes which were rugged enough to withstand the shock and acceleration of being fired from a gun barrel., and cheap enough to be used in this type of "disposable" single use application.
One of the "secret weapons" on the Allied side. Definitely made the ships in picket formation more effective against Kamikaze runs than they otherwise would have been.
A metal detector doesn't use radar or doppler radar, lol.
The whole concept sounds intriguing. Can you upload a scan of the circuit board/talk about the circuit in another video?
Here's a similar one I received. imgur.com/a/ygGZY
This is quite amazing. doppler radar used to be the way to do a lot of the things that we now do with PIR - intruder detection, commercial automatic door openers and I thought PIR won the tech battle by very quickly getting cheaper and more mass producible than radar. Many years ago Maplin used to sell a pair of quite sizeable (20 cigarette packet size I think) doppler radar transducers TX&RX for IIRC £20ish each or a thing called a Gunn diode if you wanted to roll your own.
I think the real killer app for these would be energy saving office & industrial lighting control systems, I used to work in an office with a lot of PIR nipples in the ceiling which would switch off the lights if they didn't detect movement for a few minutes... but the problem was PIR can't see through cubicle walls. If energy saving triggered you had to actually stand up and walk out of your cubicle to get the lights back on again.
joinedupjon try to search WattStopper, they have lots of products to solve this problem
Thanks Aaron, it's not a problem for me any more since I no longer work there but it was a ceiling nipple like one of those - seems their products are based on PIR or ultrasound (or both combined) ultrasound is another technology that I thought PIR had replaced tbh it used to suffer a lot of false triggers and jamming from unexpected ultrasound sources IIRC- I'm not sure how it would have coped with the sound absorbing panels my cubicle was made of... but afaik a lot of surface can have surprising acoustic properties at ultrasound frequency.
seems to me PIR could be quite complimentary to ultrasound or Doppler radar since afaik PIR is most sensitive to tangential movement wrt the sensor and the others are most sensitive to radial movement.
Where do you find these? I've tried to look on Amazon and can't find them. Would like to get a few for the bathrooms.
Right now I'm using mostly "TCP LA1027KND6" Bulbs.
Try eBay with a search for E27 radar LED
Clive, you may not notice an effect in a box but it is very possible they could interfere with other equipment
While cool, this LED looks about as EMC compliant as the last doppler one.
I all but guarantee they don't meet emissions standards for anywhere using CISPR.
This makes me want to pick up one of these radar modules I have seen on ebay. I had no idea they could be used for such trivial tasks.
Could I measure speed with one of these?
I'm from the US and there is a company that sells a device they call the Doppler for a very expensive price. I've never been able to get my hands on one but I believe that they are using a chip like this to mark the time that a bullet is detected passing the device until the bullet can no longer be detected by the device and has gone out of range since the sensitivity of these little boards can be changed. The only other thing that this expensive device does is keeps up with the number of rounds shot and their speed, give averages, store data and also give a bullet coefficient; to give the shooter the speed that their bullet is going, the amount of energy that the bullet would hit an object and different ranges. You put the data into the device; like the weight of your bullet, type of powder you are using and the length of your barrel and it gives the information based on the time it took the bullet to pass the device once it is fired.
As I mentioned this Doppler system cost lots of money and has American shooters who can afford the device buying them so much that they are alway out of stock. There has to be a better cheaper way. I don't see why all of this couldn't be done wit ha Pi or even an Adriano and have even more capabilities.
We still have companies charging hundreds of dollars to have a camera near a stationary target so that the shooter can see their hits on a stationary target and companies are marketing it like it's the best thing to hit the market for shooters. I have noticed that there are some channels where makers and quad flyers have started to visit and getting on the firearms channels and debunking the cost of these products and showing what they have been doing with cameras on quads for at least the past 10-15 years and the distances that they can send a moving video signal using a camera that fits in the palm of your hand and can move and focus while in the air.
The one people who buy these devices now are the uninformed and those who want to be the first or show the money they have; like I said, a person could build one of these devices in a couple hours, now around $15 with moving cameras using a joystick. Some of the products are just plastic ammo cans with a hole cut in it where the camera poked out; which you pointed the camera at your static target, made sure that it all lined up on your tablet before moving back to shoot and these products sold/sellsfor 400-500 dollars still. The ammo can holds the camera, battery, relay board, and antenna that sends the video signal back to an ipad, tab, or phone that the shooter has from where they are shooting and you have WiFi where the shooter was at for the systems to work; some of the devices couldn't even send a clear video signal more than 200 meters or so and the majority of them had to be in direct line of site of the tablet.
The devices were so antiquated that they couldn't move the camera in the box unless you manually walked to the box and physically moved the box to the position you wanted it in. For a few years, devices like this sold between $600-1000 US dollars and maybe cost $30 dollars to make out of Quad FPV parts. Shooters were buying these products and showing them off as new space age technology that would help with a person;'s shooting.
I find these fascinating too. Bought several different modules to play with. Currently moving house but will get them out when that is done. I wonder what magic can be done with wave guides, reflectors/shields and absorbent materials.
Clive, did you ever figure out how to tame the sensibility of these down? I just bought one and it detects me through brick walls, it's insane
Hey clive, try taking the antenna track at the end of it and scrape just a little bit of the trace off at a time and see if it affects your range and sensitivity.
I suspect that my apartment is too small for this to be effective. My computer is directly under my bathroom, so it would probably turn on every time I get up for a cup of coffee.
RADAR is cheaper than a PIR chip, but has it's drawbacks of falsing. I wonder how this bulb functions with a ceiling fan, water thru PVC pipes. Expensive ones for alarms use algorithms for falsing and constant repetitive movements and of course combine PIR and RADAR for reliable anti falsing in alarms.
+bigclivedotcom Have you seen the led lamps that supposedly do PIR and sound detection? e.g. 'Sound Sensor Auto PIR Motion Detection LED Bulb' Do they actually detect either IR or sound, and if so, what circuitry do they use? Or is it really just a sound detection circuit with the buzz-word 'PIR' added to the description? Just curious how these work.
These would be awesome in a shed or garage down the garden, I use one in my hallway as the switch is several feet away from the door when coming in at night!
Would be a great way of silencing those noisy bathroom pull switches in the middle of the night too!
I wonder how those do with radio interference...either causing it or being triggered by it...
Does it interfere with wifi, cell-phones, or listening to radio? I'm curious if there's band overlap?
Widely reported that this is 2.4GHz, antenna looks to be about right from the video and 2.4 GHz is an unlicensed ISM band for much of the world so it is likely 2.4GHz. This is well above radio range, also outside mobile (cell) phone bands (could be spurious emissions).
Wi-Fi and Bluetooth operate in the 2.4 GHz ISM band. There is potential for these to interfere. WiFi and Bluetooth has some redundancy against interference and the transmitting power looks to be too small to desensitise the receiver so I doubt it would have a noticeable impact. that being said, if you live in a developed country or major developing country than chances are this LED (like much of the items on Big Clive from Ebay) this would not comply with emissions profiles due to harmonics, spirious emissions and the general poor performance of many of these LED drivers with lack of RF suppression
If this is running on 2.5ghz does that mean it could interfere with wifi and phones? Also isnt the proliferation of radio noise a problem? :p I mean, have a load of these around the house could cause all sorts of problems couldnt it?
If it operates on 2.4 Ghz it will likely interfere with wireless networks wont it?
What power does it output on the antenna?
Besides that it is amazing that this radar is implemented in a very simple way.
I only heard of that technology as part of expensive security systems.
one of my side hobbies is radio, now i dont pretend to know how a uWave tranciever works, it must change between a send and receive state or the transmitter would over power the receiver being so close to each other. I have seen a very similar configuration in a wireless router where the copper tracks on a pcb form the antenna, and yes you are right, in transmission, the antenna length is crucial for the swr to be as close to 0 as possible (swr is the amount of energy fed back down the transmitting antenna to the transmitter during transmission, bit of a mouthful and a bit more complicated than that but..) for 2.4Ghz the length of a "perfect antenna" would be 6cm, but for compromise usually a 1/4 or 1/2 or 5/8 wavelength is used at the expense of power output. Im wondering if these bulbs use a more capacitive approach, much like changing the tone/volume on a theramin in relation to proximity of your hand to the antenna's on the instrument ???? Guess what im trying to say is, the tracks are part of the tuning circuit for the 2.4Ghz square/sine wave carrier. You or another grounded object (tree) getting within the field of the tracks will cause the tuning to shift and maybe this is what the chip is looking at, a noticable drift or shift from its normal referenced frequency ??
Aren't there ones that have adjustable range/power or whatever. (Or better yet which use waves that don't go through thick walls.)
I ordered some PIR ones, but I got a bit screwed, because I didn't think that light fixtures don't transmit thermal infrared radiation. (Apparently neither glass, nor plastic.)
I think this is what a spooked bigclive looks like
I picked one of these up after watching the video and put it on my back porch. seemed to work fine at first but... temps dropped down to 40f that night and you'd have to wave your hand right in front of it to get it to come on. then it'd warm up from running the LEDs and it'd work fine until it cooled off again. pish.
As you say, it's entirely possible that having multiples of these would cause them to trigger off each other or just on ambient EMI from other electronics in your house. e.g. turning on your TV or computer or whatever and suddenly all the lights in the house get triggered.
False triggering was one of the banes of Microwave security sensors "back in the day". They were better than Ultrasound, but the improvement in falsing vs. the cost was very poor. That was in the day of the IMPATT diode; I believe the introduction of the GUNN type microwave diode reduced costs, and led to a resurgence in "affordable microwave Doppler" security systems?
I bought some of these because of your last video. Turns out unfortunately that the will trigger each other. As amazing as they are black magic-wise, I'm having difficulty figuring out an application for them, they just see too much.
I would never buy these lights because i would be scared of them going off when nobody was in the room
Do you worry about the the light in your 'fridge still being on when the door is closed as well?
yes i am totally insane
Graham Langley I checked that. It is a myth. It will shut off.
If you had one of these in a multi story house would it detect movement on different floors? I ask this as I live in a high set house with a garage/workshop/laundry on the ground floor. This sort of bulb would be great but not if it kept detecting movement in the living area.
Maybe it would work better as an alarm for people, or maybe wind if you need to put umbrella's down or some other early warning device other than a light.
Can you bodge something to modulate the rf power so you can tune it for 'sensitivity'?
Wondering how prone these are to rfi from other household items. nonetheless very interesting. Thanks for the info. I'll have to try one.
I like the premise of these lamps, but as someone who is getting into amateur radio, I'm sure that those things spewing RF about that place would cause some trouble...
Hi!
In what way you dim your foodlights at 2:10? (I remember you saying earlier that you have floodlights installed)
I've wanted to get a 30W ceiling-aimed floodling to illuminate my room with soft, ~homogeneous diffuse light, but unfortunately they don't make dimmable ones...
I'm actually adjusting the camera exposure at that point. The floodlights are fixed intensity.
i should add that to wash your room with a soft ambient glow, simply bounce the lights off the ceiling instead of having them aim directly down. Basically using them as an uplighter.
bigclivedotcom
"I'm actually adjusting the camera exposure at that point."
Ah, okay. Didn't think of that. Silly me...
"simply bounce the lights off the ceiling"
That's precisely what I want to do! :) Just have to figure out a way for dimming.
I got 4 doppler radar units in a box from AliExpress, each had 5 leads. I had to look inside to figure out how to wire it. I saw a solder bridge on it's radar loop antenna, before removing it I looked at another one and it had a solder bridge in the same exact place. OK, turn off the iron.
Is there way to "limit" its sensor range in way that its eg. sense movement only in specific spot(eg. just one side of lamp where are doors, not window) by shielding that antenna or whole lamp by some material?
Of course I mean in way that it would be easy and cheap like small metal grid/net putted near, or it would need to be cooper(its used for RF shielding)?
It would work or it would bounce that ""movement"" waves from other walls/object and still reach lamp?
You can theoretically attenuate it by aiming the lamp, but the RF energy bounces off most surfaces.
Its probably a super heterodyne receiver circuit one transistor acting as an oscillator and a mixer. When the bounced signal mixes with the local signal there is no product and when it bounces off a moving target the difference in frequency from the oscillator then the mixer gives a product simpls.
The difference frequency is in the order of 200 Hz at an oscillator freq of 30 GHz and a target velocity of 1 m/s. I would guess it is pretty hard to detect that frequency shift with such a minimal circuit, so my bet would still be on disturbance of the amplitude of a standing wave: in-phase / out-of-phase.
en.wikipedia.org/wiki/Proximity_fuze#Radio
Well that's definitely a new idea for lamps. Can't wait till people find out that it's emitting microwaves constantly into the room. I can hear them all bitchin about their headaches already ! Very Cool .....
If it was the PIR chip, there's one pin that enable retriggering so that it will "extend" the On duration
It's an issue with the light sensor being lit by the light itself. The usual fix in other equipment is a diode that makes it think it's dark while the light is on.
Clive, Perhaps its switching between tx then rx to catch the reflected energy?,
and chip counts the tx to receved time and triggers if below a certain value.
Like an electronic tape measure perhaps?
No, way too complicated. Also it wouldn't work. Everything is reflecting radar not just humans.
zx8401ztv Pulsed Doppler seems feasible- the system isn't just looking at reflected energy (actually re-radiated, but that's a whole different discussion), as Clive says it looks for the frequency shift.
That effect you get when a vehicle with a siren goes by, as it approaches the sound waves are essentially squeezed closer together (frequency goes up), and as it goes away the waves are stretched out (frequency drops). RADAR doppler works in the same way.
You transmit a pulse (the pulse width determines the minimum range of the radar) of a set frequency and then wait (the wait time determines the maximum range of the radar).
You get a 'return', the time taken (div/2) is the range, and the Doppler 'shift' (frequency change) gives speed (+ve (approaching), the same (same speed as TX) or -ve (moving away)).
Same way as an FM decoder works - the "information" is in the "beat frequency" and this is processed by the "PIR chip" in the same way as the output from a PIR sensor. The chip "sees" a minute input voltage change, and acts accordingly.
Phil S.
Ahh i see what you mean, so its not listening for the original rf, its looking for the lower beat frequencys changing from an empty room reading :-D.
Thats clever and amazing that they did it with such a minimal circuit.
Thanks for your discription, i dont allways see things clearly.
zx8401ztv
If the room is empty or full does not matter. Movement is the important thing. even if there's ten people in the room, it would stay dark if noone moves.
Is is actually in the 2.4 GHz WiFi band? If so, wouldn't it mess up your home network?
Exactly, I'd love to see what shows up on WiFi Analyzer (android app). If these devices use 2.4 GHz they could end up trashing your or your neighbors WiFi.
It would be extremely unlikely to have any effect at all: wifi is quite sophisticated
I beg to differ, the front end of most home WiFi routers and devices is easily swamped by other 2.4 Ghz devices. A common concern is the use of 2. 4 GHz wireless telephones in the proximity of WiFi devices.
Or... the other way around... would your various WiFi signals activate the lamp... hmmmm.
Well additional investigation (Google searches) indicate that these devices operate at 10.525 Ghz which is just above the 2.4 GHz WiFi band (2.4 to 2.4835 GHz) allocation. So depending on the relative signal strength one could conclude that they would have minimal effect on typical 2.4 Ghz WiFi devices. However if these lamps emit a signal much greater than typical WiFi devices they could cause interference. It would be interesting to monitor WiFi data throughput in the presence of these lamps.
Look forward to you testing some of these together for 'jamming' :)
That doppler idea seems a bit daft to me considering that if the trees outside can cause it to switch on, it'll be a waste of electricity as the lights would always be on rather than switched on when someone enters a room... :\
Hi!
Did anyone see these that were also adjustable. (lightness, time, sensitivity)
It should be rather easy since the bulbs have openings on them to start with. But I'm not sure if any of the sellers do it.
hi clive, as you have been around the block, can you tell me a good place to buy 18650 batterys. would rs be a good place. thanks
Hard to say the best source, but for the most rugged the vape shops seem to be a good albeit pricey option.
A tare-down of a usb killer would be interesting. Perhaps a build.
It works by the Black Art of RF Electrickery!! :)
So it seems like if you lived in an apartment building your neighbours could probably trigger it?
Through wooden floors that would be an issue.
thanks clive
This is actually really cool. :)
Next vid, Clive builds a mad Faraday cage and wears a tin foil hat to make sure it was the trees :O These are really cute designs, I like them a lot.
My solution to test one of these was to place it within a sweets tin (Quality Street FTW!)
RobWVideo today I learned, other people have heard of Quality Street and it wasn't just a wierd present I got for my birthday once
it's xmas soon but all I've seen so far is plastic, tubs bad form
Try copper screening the room it is in, A Faraday cage. Or I suppose you could find a cheaper solution...
This needs to be investigated, extreamly crude radar?. Thanks for for the video Clive :)
They sell the radar detectors as bare PCBs on eBay really cheaply. Although it doesn't cost that much more to get the full lamp.
What is the price difference? What is so much better about Doppler vs. Infrared? I'm creeped out so far...
The Doppler ones work inside light fittings, the infrared ones do not work inside many fittings that include glass etc. The infrared ones need a direct sight whereas the doppler ones will even detect movement through walls. One is not 'better' than the other, they have different uses IMHO.
Andrew Denley The NSA is happy that Home Depot and Lowes want to stock them.
This is cool but can it be hacked?
Yea, but I need one that ignores cats...
Wait so with on these you could pick up if there is a light or something using the same radio station
hey there fans of dark magic: i found the datasheet for the EG4002 chip that clive found in this cool little lamp. it was in chinese and i had it translated, but i'm still trying to figure out how this could be used as a doppler sensor. Any thoughts? i haven't found the patent clive mentioned, but it might not be published yet if it's been filed less than 12-18 months ago depending on the patent office. Do you guys know what company might have filed this patent?
As someone who's an extreme novice with electronics, is this the same kind of thing that motion sensing alarm systems use?
Some use it, but usually as a backup to a PIR detector to avoid false triggering due to thermal reflections.
Thanks for the reply, Clive! Love your channel even if I don't understand 90% of it.
Is there any proof this uses the 2.4Ghz band? I wouldn't want to cause interference with wireless stuff. The radar modules I have seen on ebay use 433Mhz.
The frequency will be determined by the antenna length on the PCB and I'd guess the capacitors too. It's not going to be super accurate, but it's extremely low power.
Thanks, I guess it will be hard to get a reading without temporarily messing up the tuning. I might have to get one of these used DVB-T sticks from ebay and figure out how people abuse them as software defined radio to monitor nearly the whole RF spectrum.
is the future of motion detector lighting?
+ACombineSoldier
I would imagine they would need some tinkering for outside use or even to use multiple of them in proximity. Depending on the sensitivity, a tree branch swaying in the wind, a small animal, or even a heavy rain could trigger these. None of those things would trigger a IR detector light.
All of these (wind, animals, rain) can trigger an IR detector. It's just a matter of sensitivity. I have a light that regularily turned on because of a tree moving in the wind in the neighbour's garden. Had to block out part of the dome because turning the sensitivity down so it would not react would also have made it almost useless. I also have an IR detector that activates a water spray when a cat tries to poop in the lawn (funny thing ;) ). It works reliably even at 5m+.
Hmm, can you fit a ESP8266 within the lamp ?
I'm thinking of adding something like this to external coach lights because it's easier than adding a separate sensor to the circuit, my house is aluminium clad, if I have these on the outside they shouldn't detect me on the inside should they?
I'd suggest trying one first.
would be interesting if a simple wire screen could stop the light from triggering it on the wall inside. like a Faraday cage would! or would it multiply the triggering?
I part wrapped one in foil to reduce its sensitivity
Kool idea. And it did reduce it. Now knowing radio i still would be interested if it could be directional.
I've put one up in my landing, but it picks me up through my hollow bedroom door, whats the best way to lower sensitivity?
It's not that easy. Apart from moving it further away or lining your door with foil.
bigclivedotcom I wonder how the microwave motion detector module's on eBay do it?
So this bulb works best in a bomb shelter? Where would you use this? Wind moving branches outside ? WTF?
Any idea on how to mod them ?? Thinking of range(gain??) ect ??
Please do share your findings
I just thought you could make a Morse code radio with two of these
make them in pink and sell them in pairs, there ya go , a million dollar idea
*****
ok i give you half of what i make!
I don't get it...
Chris s
i dunno, cant explain it unless you are over 18!
How much microwave power does it radiate
It seems to be ultra low power.
10mintwo mmm Chinese microwaves
+bigclivedotcom I guess it would be harmful for Pacemaker/ICD wearers (my mother). I'm not considering getting one anyways, just my thoughts.
I'm pretty certain the X-band ones I worked on were nominally 10mW.
Don't have one of these lights to test but the RF output is going to be quite low and AAMI PC69 exists to protect ICD from RF radiation from DC (0Hz) to 3 GHz although this will be expanded in future versions.
I would be more worried about Wi-Fi than this little transmitter.
A good article on ICD, standards and immunity is from Dr Kay www.engineersaustralia.org.au/sites/default/files/shado/Learned%20Groups/Technical%20Societies/EMC/Newsletters/newsletter_54_repaired_fot2.pdf
Djigahertz xD don't mock our Swiss friend :)
any ideas of the current consumed by that radar ?
I have a few of these and, after placing one within a metal sweets tin to stop it triggering whenever I moved, it tested at about 4mA on standby.
x240 so that's nearly a watt - not saving as much energy as I'd hope
Higher than one would expect based upon the circuit, 115VAC?
Then again, this could be from how the PIR is shunting the LED to off rather than the detection side. Hard to tell without the circuit diagram of the measured LED.
Won't this type of technology have trouble with WLAN? It's the same frequency range...
Special magic !
CN3W = GB0.3W right?
Because these transmit a rf signal shouldnt they be fcc certified if they are used in the usa?
They operate at 2.4 GHz, which is an ISM band, the same as microwave ovens.
SigEpBlue the ism band just means that the end user dosent need a license. There are tons of bluetooth, wifi, etc items on the fcc redistration site for ism items.
Chinese three watts: Oh, about 2.7, 2.4, whatever.
could you modify it to switch off when you approach it?
Theoretically you could add another transistor that was biased on and got turned off by the existing one.
Idea for a new unit of power: Chinese watt. Equal to about 1.5 standard watts.
Sorry for off topic but anyone know where I can get decent warm white LED bulbs? A local shop has 2700k ones with gorgeous output but they are very costly. All I've ordered online have been way too cold even when sold as warm white.
It depends where you are in the world. In the UK ASDA has retro LED filament style lamps that have a very warm golden light.
+bigclivedotcom in Denmark (though not Danish). Many things tend to be cheaper to order from abroad.
Only Lurking Are they some reputable brand? long warranty? Maybe the costly ones are worth the price..
What's the current draw when in standby mode?
It wasn't measurable on my energy monitor. Probably just a few milliwatts.
just brought some to go in the toilet so i can leave the light switch on
I want one, what do I search for?
Keywords like radar lamp e27 LED
Thank YOU kind Sir
How well do these work in noisy WiFi environments?
None of them seem to have been bothered by the neighbouring wifi signals. They're only really detecting a slight modulation of the reflection of their own frequency.
Yeah the word "reflection" can be misleading. If I walk in front of a radio the signal can change and that can be used as a proximity sensor. But this doesn't mean there's a radar system inside my radio, lol.
> "their own frequency"
So, it's amplitude modulation right, not "doppler". I think it's AM not FM.
-i mean, it's not hyper, its just water right through!
I would love to hack this up to detect intruders through the outside walls, but I'm afraid it will screw with my wifi :(
I'm thinking about getting one so I know if someone's at my front door
Arent those radar lamps unhealthy?
It's ultra low power. Probably less than a typical bluetooth headset.
bigclivedotcom Thank you :3 I Understand, but which one of those lamps would you rather recommend? :3
It depends on your application. The PIR version is going to be more accurate in detecting people inside a room, but the radar type is going to be more sensitive to small movements.
Think I might put one of the pir ones I'm my toilet haha
What with Phones and mast's And of course Microwaves ovens and not forgetting Smart meters I don't think we need any more microwaves even if this is so low power, after all it could be the straw.........
Nope. Doesn't work like that.
How about this, you can either use your microwave oven for 3 seconds less each year, or receive 1 second less direct sunlight each year to make up for this extra microwave radiation.
Because radiation is all equally harmful and works JUST like the fallout games, right?
No Brad! XD
Pendulum clock in the room…