This Christmas, after you have distributed, the hundreds of thousands of, LEDs you have accumulated, in and about your house, driveway, assorted shrubbery and down your road, please video for us all to admire. Thinking about it, you might ask the ISS crew to photograph the show from space, might just be a little bright, even driving all the LEDs at 3 milliamperes. Cheers.
My days of research to restore my favorite x'mas lantern pointed me here. bigc... you're a God send. The controller on one of my old x'mas lantern died two years ago and thank god, at that time I refused to pay US$48 for the same controller on eBay. Now I know how to switch to LED's and definitely will DIY a capacitive PSU. My hats off to you bigc! Subscribed for the 1st time.
LOL! Asbestos Christmas trees! That capacitor dropper trick worked quite well -- I was impressed with that. Saw someone do that once on a vintage radio -- used the capacitor to not only reduce the "A/C hum" but also to reduce the current going in, as the original radio had a "resistor power-cord" that was a serious fire-hazard. The capacitor corrected both problems while producing next to no heat.
It's interesting to see that the flicker issue is (relatively) easily resolved. I can't stand being around LED Christmas lights in the dark; they make it look like the world needs a better graphics card!
Remember getting a shock off these cheap strings even while just handling the wire barefoot on the grass .. sent them back and got a refund. Think I'll stick to low voltage for cheap strings that'll be outside in the weather ..
I wouldn't ever dream of handling any electrical product while barefoot on grass. It's such a good ground reference that there would be a high risk of potentially fatal current flow through your body.
+bigclivedotcom I wasn't really aware of the mains referenced power supplies at the time .. I knew they were dodgy given the nasty power plug and phone-wire thin cables. Here in the tropics we tend to be a little more relaxed on outdoor clothing, and especially in the middle of summer for xmas, as little clothing as publicly acceptable is all that's really tolerable while hanging lights :P
I bought a few sets of these a couple of years ago from Amazon.com. I barely even dared to plug them in, much less use them. I ended up stripping the LEDs from them, and then a few weeks later Amazon issued me a full refund, unasked for, because the product was so unsafe. :) I use a DIY capacitive dropper for my Christmas lights, but it is fused, has a properly rated cord, a properly rated enclosure, and the Christmas light strings I attach it to are the heavy-duty American style ones. It's not a perfect set-up due to the high voltages present in the strings, but it's a heck of a lot safer than it was when purchased.
The reviewer of a similar set sold on Banggood.com complained that "...smoke started to come out of it. The plastic protecting the light bulbs melted..." .Banggood response : We are so sorry to tell you that the plastic can't stand the fire. So you should keep the plastic away from the fire". .I think they missed the point somewhat!I bought a 100-light set of these with assorted colour LEDs. The LEDs were extremely bright but I didn't trust the wire insulation.
A popular "computer & beyond" site sells the US versions of these -- same white box & transparent wiring, but w/ a US plug & connector. And they show a picture of these on a Xmas tree.
Maybe I’m over confident, but I just bought three sets of 1000 lights in exactly this design. The plan is to power them from an inverter. Having watched this video, I think I’m going to patch into the 350v DC rail inside the inverter and Power the lights from that to ditch the flicker. Might have to reduce the voltage a bit to take the strain off those resistors (or maybe remove the leds with resistors from the chain and use one big power resistor as a master limiter). Thanks for the video Clive! Very helpful.
+Alex Wood If you use the higher continuous voltage you may damage the lights by burning out the resistors. The unit will also not animate as it needs the AC for timing.
bigclivedotcom cheers for the advice. I think I'll cut out the leds with resistors and ditch the controller completely. I'll just use some large power resistors to limit the current down each strip and make sure they're beefy enough to take the power dissipation. I might even low side switch them with some high voltage mosfets and an arduino to reproduce my own patterns (I'm an electronic and embedded software engineer). Love the videos!
I think the Chinese manufacturers are listening to you Clive! The sets I got have lots of series resistors not just three, and they're running them well below their rated power dissipation. They have also replaced the pushbutton on the controller with a rotary switch, so they "remember" your previous mode. I still chopped out the controller and I'm running them from high voltage DC, derived from a 12v to mains inverter. Gives a lovely flicker free light.
And here I thought I would catch you in the amount of LEDs but you keep on making it harder, I only got 100 in today thinking it would put me closer. Joking aside I love LEDs you can do so many things with them on there own but throw in a couple components and bam you can do thousands more. Love the vids.
Clive - I love all your videos, I find them fascinating, but I must admit I don't understand as much as I should about electronics, and something I particularly struggle with is understand why certain components are used where they are. For example, how to know which resistors to use and when to use them (dont worry, i don't work with electronics myself, but I am the paper-shuffler for a small business that deals with them sometimes). I was wondering if you would consider doing a series of basic tutorials explaining the basics of electronics like this? It would be a great help to someone like me who would love to understand more about what's going on in your videos.
The old style bulbs are connected the very same way, usually 10 lamps, 24V each all in series... And we are using the very same set for last 30 years, as it was one of the first thing my parrents ever bought together...
Good job Clive. Lights are running much cooler and are now much safer. I can't believe they sell them like that on eBay! EBay should put " Lights May start smoking & Poppin 3 days later. Buy at your own risk!" Lol
I'd love to see a Christmas Lights buyers guide from you Clive. What to avoid in a set, some of the tell tale give-aways that might indicate problems and what to look out for in a good set of Christmas lights :)
Thanks for the video Clive, as always everything is explained so well, I enjoyed the part where you changed the drivers at the end, I wondered if you'd use a nice big capacitor to smooth out the rectified wave.
+linuxdaemon1372 I swapped the existing electrolytic for a 4.7uF 400V one. Mainly for the voltage rating. But it doesn't take much capacitance to remove flicker at the relatively low current involved.
although they are unsafe, its amazingly efficient. I wonder how much safer it would be if ran from an isolating transformer. I know people could still get a shock but at least the live power won't be wanting to get to earth
I think the larger sets are very dangerous. Just bought a set of 1000. The fabrication was poor. Some of the resistors were not connected well and when plugged in, they started popping the tops of the diodes.
About the flicker ... I remember seeing a video comparing different light bulbs with a optical element connected to an osciloscope. All of them normal, luminiscent, led were flickering (50-100Hz unseen for the naked eye), except for only one led bulb, obviously with a good power supply.
I'm working on a "unflicker" supply circuit for 8 to 10 strings of 90 lights. (I went for the plain boring warm white.) Anyway, each string is 2 parallel circuits (threads?) of 45 LEDs, which each seem to peak at 25mA @170v (US mains). To drive 16-20 of these threads, I think I've landed on a rather large dropper capacitor of 100uF and filter of 1000uF. The dropper is actually a motor run-start capacitor, and its value is huge because I still want about 160V on my DC output. That will drive steady 10-12 mA per thread -- which is still plenty bright, especially considering it's on full time, not just at 20% of the unrectified wave. Maybe I'll be done with it by Christmas! Ha!
+arfyness I wouldn't recommend using such a high series capacitor. The inrush current could potentially damage the LEDs. It might be worth getting some of the little capacitive droppers off ebay and using one per set or two. That might actually be cheaper, and it would definitely avoid the hazard of such a high valuer capacitor charged to a fairly high voltage.
+bigclivedotcom I do appreciate the suggestion. And how I've tried! I've even simulated all this in LTspice, finding that the only way to get enough current through even one strand of LEDs with small dropper value is to reduce the end-to-end voltage across the load... cut the strings in half. I've thought of chopping them up, but they're quite well made outdoor ones. I'm still considering it bit I want this supply to work for any LED string. The only inrush I see in the LTspice shows between AC and the filter cap. I found KBPC5010 50-amp rectifiers quite cheap so that's no biggie. Farther down, the circuit, the load current takes quite several AC cycles just to get going. 45 LEDs at nominal 3.4v adds up fast. If I were on 220vac I could do with 1uF or something like that because the load voltage is significantly less than supply. But this is sissy 110vac, peaks at 170, and the strings need 155-160v to light decently. the are the ones that just plug direct into the wall, no little adapter thing. What it comes down to is that AC capacitor is there to limit inrush current, with only little effect on operating current/voltage. I'll link to schematics and waveform graphs I've cobbled together, when I get home.
Hmm I just bought something similar from my local hardware store. A 1,504 string (I liked it because I can say I have more that 1,500 led's) was 75% off on the 27th of December. So for $40USD I could hardly say no, right? Now I need a capacitive dropper.
I am also shocked of the almost bare wires from the mains plug into the controller... I switched to battery powered ones. Should arrive this or next week.
I happened to see this on my suggested videos and actually, I just purchased a set of these....the 32 foot version with 100 blue LEDs. They are actually advertised as "safe design". I wonder if somebody modified the circuit over the last few years since you did this video. Mine do not heat up at all (although I don't have a FLIR tool), I cannot feel any heat through the plastic/vinyl. Also, I noticed that the set that I have only has a resistor inline with the first 10 LEDs on the strand. None of the following LEDs have an inline resistor.....I wonder if anyone else has a set of lights like this?
My uncle wanted me to check a set of Christmas lights once, and I found it was some cheap Chinese set he found online. There was no strain relief, one of the main wires had pulled loose from the board. They weren't thick-enough wires, either. I refused to fix them and told him to throw them out. He's always looking for a deal, but I don't think burning his house down or getting shocked should be the result.
I know thats an old video, but just for future reference: The peak of the sin wave from mains supply shouldn't be 240, 240V is RMS iirc. So your peak should be around 1.414 of your RMS (around 340V).
+That Guy oh yes ofc that's the correct term, don't know why I wrote sin ;) But I also noticed that clieve has mentioned peak sine correctly in various other vids, so I assume that's a derp here.
+That Guy I guess it's just easier since we work with DC a lot and AC RMS = equivalent DC voltage, just my best guess. maybe there is some other (maybe historical) reason for doing so
Rubber/asbestos (Christmas) trees? - No way. They just sling 'em up outside and it gets quite exciting when it rains. We had a game - guess which set will still be working the next day and which tree would have the biggest skid mark....
Yes, it is rather surprising some of the unsafe stuff that gets made, but lights that burst into fire would be more like Fanny Flambeaux's style than Barbie, wouldn't it? xD
Thanks for posting this! I've recently purchased the 500s through proxima and was wondering about the flicker! Next step is to decode enough information from the internet to purchase and solder in the right dropper I suppose! Would you be able to suggest a place to pick one up?
I've bought 16 pieces of these for my xmas project. The PCB on mine is a little different tho. It's half the size of this one and only has 2 different valued smd resistors , a little smd capacitor (i think) and a black epoxy looking blob on the PCB.
Interesting, i picked up some of these types of LED's,they look the same anyway but are powered by 2xaa batteries a string of 48 of them from the dollar store. Last season I hacked in a usb cabe to it giving it 4.5v. I wasnt concerned if they'd burn out and they did, but not like how this video describes and only a couple did while the others worked fine still, no melting fortunately and they were being over volted, it was so bright it was amazing actually, I thought about adding a proper power supply of some kind to not give them so much but im an electronics noob and its good to hear theyre not very heat tolerant so i'll be more careful. I also picked up some of those bead (blob) LEDs here from the dollar store, ones that look like they're attached to bare wire, a string of 60 powered by 3xaaa batteries I thught would be good for a usb powered mod and id imagine are more heat tolerant? They seem to perform better then the types of LEDs shown here anyhow, they're just stay brighter for longer it seems on the batteries. Anyway glad i found this channel and video, the info here is very valuable and could save lives, thank you.
Wow good thing I watched your video, I just recieved the white 10m 100 leds so basically their dangerous & not waterproof, Maybe I 'll just find a dry spot to turn them on only when Im hanging out in the patio fpr max 30mins, does that sound safe enough?
Seinor Grande Clive :) have you stripped down the newish walmart LED Christmas sets and checked them out? Inquiring LED enthusiasts would like to know. I bought a few and they seem fairly safe but you're the pro. God bless brother.
+John Arizona I'm in the UK, so our version of Walmart (ASDA) tends to stock different stuff. But the high profile outlets have to be careful to use safer stuff to protect themselves from litigation if it goes wrong.
As an Aussie i do not know what "Poundland " is . Is this what you call England as every thing is or was sold in pounds or is it a shop called Poundland that "nothing " is over a pound, like a dollar store ? Please excuse my ignorance ..PS found these vids last night i find them awesome. Keep up the great Vids . Been looking around the house now for any thing made in China >.< ...
If buying cheap Chinese LED lights its probably safest to stick to the battery powered variety, the ones that use 3 x AA battery box are bright and should easily last all Christmas on a set of alkaline batteries.
Enjoyed you video, very educational for newb fools like me. My version of these keep cutting out after about 12 hours, like there on a thermal fuse or something. Is this possible? I want to put them on a timer anyway, so would like to cure the automatic cutoff - any ideas?
Many modern sets with two channel chase effects have an 8 hour on 16 hour off function. Try turning your lights on at a known time like 4pm and see if they light at the same time the next day.
can you make these safe at all? if so can you do a video as I have a few sets of these for christmas, if I had of watched this before I wouldn't of got them!!
I notice you use a plug in power energy monitor to see voltage and power usage and possibly cost, could you recommend an inexpensive one, maybe do a feature on one ?.
Just picked up a rusted warm white icicle set with a few non functional leds from a council cleanup or where people throw crap on the medium strip. Works and is a good brand I own several already would it be dangerous? ( I assume so )
I hung a set f these LED Light out side my house believe it or no they are the only ones that are still working 2 Years later now. I still do not like how Cheesy they are though. Like very cheesy I Cannot believe 120V runs through those TEENY little wires!
I don't know why they bother making those electrode boilers when you can just chuck one of these in there. Probably safer, discounting the decomposing plastic.
Hey! Please help me.. i have the same China made fairy lights but it’s switch is not like yours, it’s like Nokia phone charger’s type pin. Please help me how to plug it in switch board, I’m clueless. Waiting for your kind response
I've never had a datasheet for any led I have used but I have always ran them at about 20-50 mA. what is the highest I should actually be running them at if the Chinese are running them at 10mA?
I just did an installation of those for a wedding...they were remarkably unsafe. We sent most back and got a refund for them not being waterproof as advertised.
+Steven King Full wave rectified for most, but not smoothed. The high combined LED forward voltage means they don't light until they are well into the sinewave.
+ehjones Yeah, I've been stuck at my mum's house looking after her for most of the week. There's not much technology here. I'll be back at my workshop from tomorrow hopefully.
Clive can you change volts into amps or is there a way to create amps, my lab power supply runs only 1 amp at 120v adjustable voltage. I always get the answer that its incredibly hard and thats all, we run 240v mains. Can you do a episode about it please.
I'm afraid it would involve a complete redesign and build of a new supply. It would be better to keep that unusual but useful supply and add a new lower voltage, higher current one.
+gigabytex64 Sorry, but if you have to ask a question like this, I feel that you shouldn't be playing with a power supply that goes to 120V. In principle what you want leads to building a new power supply, as Clive said. That's why you always get that answer.
The question was only general, AC voltage can be used as long as its safely so does the fact that I was one of 3 technicians working at voltages in excess 100000v at a hydro electric plant for 4 years and safety at all stages. And I take it that your advocating that experimenting and learning at home should be illegal.
I have the unusual top voltage for a pulsed sed of lights totaling 100 bulbs thats all, i can build another supply fosay 50v vairable voltage dc and setup so I can set the amps as well. Thanks Clive
what does a rectifier do? couldn't find anything but "diode bridge" which isn't this, right? edit: does it make the polarity of the output "not" change when using AC? what does this imply for the circuit, if this weren't there?
You know it's a special item when they can boil water... :P As for a shocking experience, yeah, don't want that, gave myself one last night, tripped the electrics too, which wasn't fun... :P
+twocvbloke Excellent. Did you just short some contacts out or did you pass enough current through your body to trip the RCD? If the latter, what path did it take and what did it feel like?
bigclivedotcom It was the latter, and it felt like 50Hz AC running through me, not sure what the path was as it was about a quarter of a second and the shock kind of, well, shocked me, went into WTFBBQ mode and went to turn the RCD back on as my UPS units were beeping at me... :P
"Christmas LED Mesh Net, of Death", Part Deux .... The eBay item # 351335116640 shows more detail, about how they accomplished the 'mesh' effect, see 4th pic from the left. The resistor appears to be 820 ohm @ 1/4 watt. I can see 5 output wires, so 1 common and 4 strings of 30 each (120 LEDs). 110 volt @ 1 watt power output, for 120 LEDs and ??? 680 ohm resistors, the math eludes me. They are sold as indoor/outdoor lighting, with the caveat, "The net lighting should be kept away from dampness, rain or mist". With 110 VAC (US) they are only half as deadly as the 220 VAC (UK) ones, or are the UK ones twice as deadly? Mostly dead or partially alive, is not all dead, with all dead, there's only one thing you can do, go through the pockets for change.
ArduinoPlays Well, my point exactly. I'd be very surprised if they didn't share at least half of their audience. Along with Mikeselectricstuff and SignalPath
+Aurelius R I ramble through various electronic channels online and occasionally post in the eevblog forum. But the undisputed king of teardowns is Mike of mikeselectricstuff. He gets some super-weird stuff and goes deep into it. The reason I splashed out on a Flir thermal camera was because Mike took his to bits and dug deep in the hardware and software.
+bigclivedotcom i'm also wondering at this point if instead of converting them to run with the capacitive dropper driver, i could perhaps convert them to run with the mountains of 24V/36V transformers i have from the mounds of old-school fairy lights that have long since run thru their spare lamps...
+Stevie C You could, but it might be a bit of work. Typically on a 24V AC transformer you'd need to add a rectifier and then cut the strings into sections of 7 LEDs with a suitable resistor in series with each section.
It's worth checking the string for signs of burning around the little resistors soldered to the first LEDs in the strings. If there are no kids or pets around it should be OK.
+ashley zuniga If they don't just work when plugged in then they are faulty or wrong voltage for your part of the world. It could be as simple as a wire off the PCB.
+chubby funny 5 The common cheap Chinese light strings are not safe for use in the vicinity of kids or pets. They're also not suitable for outdoor use despite saying they are. If you are using them indoors with no kids or pets around they are OK, but otherwise get proper low voltage ones.
chubby funny 5 I think the small sets are probably safer than the really large sets. I have had good luck with 200 or less. I just bought a 1000 led set. Very dangerous if someone messes up during production!
Rubber xmas tree LOL :-D So the old unlimited 20 x 12v bulbs with weedy green wire connected to 240v was safe?, i didnt get electricuted, i dont think so LOL :-) Peoples stupidity creates danger.
Hi Big Clive, Great channel, I watch you all the time :) I wanted to ask you: I have a GY6.35 lamp that's rated for 50w 12V halogen bulbs. I bought an LED bulb for it on eBay (www.ebay.com/itm/271846372528), but it only lasted for a month before it emitted smoke upon turning it on one morning. Now they do say that with transformer-based lamps, these LEDs will buzz, which is true, and I'm also assuming that it's what lead to its untimely demise. Opening up the bottom of the lamp, all I see is one large transformer, and no 4-diode rectification + large electrolytic smoothing cap like I see in AC to DC wall warts. (Are they just doing half-wave rectification with a single diode tucked away within the transformer insulation?) What can I do to improve this lamp? Namely, I want to provide a nice clean DC signal like you show in this video even if it will come at the cost of not being able to use 50W bulbs in the future. Thanks
+khachaturian If it's an ordinary heavy transformer in the base then it will run the lamp on AC. You could either replace the transformer with a regulated DC power supply, or leave the transformer in place for weight and use an external plug-in DC power supply to run the light. Don't go for the ultra high power LED lamps. They often fail thermally.
+bigclivedotcom I see. So it's just a 120V AC to 12v AC transformer. Can I just add a four diode rectifier and say a 25V 1000uF smoothing cap like in wall warts? I'd like to keep the transformer, as it removes the equation of quality. Transformers just work, but swiching needs good quality parts.
+bigclivedotcom Of course! D'oh. I remember this now because I did use a transformer for an internet router, and with no load, it was more than 12V. (but I was told that the router had a buck converter IC which woul bring it down to 12). I have an idea to build such a circuit and use the lamp's double pole double throw switch to my advantage (Hi and low setting on the lamp). One throw for halogen lamps and one for LEDs. Great channel Clive and please do rock on.
i have way cooler lights they are RGB i have 2 sets of 25 and 2 of 50 they are awsom they are 40 euro a set for the 25 bulb and 60 euro for the 50 bulb
+bigclivedotcom www.ebay.com/sch/i.html?_nkw=concave+led+1000pcs 15 to 25$ but somehow no shipping information is provided, probably after contacting the seller. some ebay listings are blocked in my country because the seller is not a "power seller". to find them i have to use proxy.
Pay for what you get scenario. Not sure why you do these breakdowns when all your doing is droning on and on and on ? Provide details how these should be made safely. Go put a kettle element in your bath will ya
