Homemade LED lamps, with salvaged parts! - Page 1
Forum section: electronics / projects

author: Vincent
author_rank: Regular Contributor
timestamp: July 03, 2014, 10:08:44 pm
content: I have this long-term project I started a while ago, which involves building my own LED lamps at little to no cost! I'm still on my 1st lamp, but ultimately I plan to build more, of all forms and shapes, and a wide range of wattages!I detailed this projecton my website, but I have new pictures of the lamp I'm building at the moment.What made me want to do this project is a video of a particular LED lamp on YouTube, which used an X2 class capacitor to limit the current instead of a power resistor. I loved the idea, and it's only a matter of recalculating components' values for more or less LEDs, along with adding a few extra components for improved reliability and safety, 'cause I'm paranoid like that, don't judge me! xDAnyway, before building the actual lamp I first went with a quick prototype on breadboard to make sure all my calculations were correct. Good thing I did, because I got some of them wrong xD. Turned out the value for the capacitor ballast was twice greater than needed, that is, 2uF. A 1uF cap drives the LEDs just fine at 16mA!On this pic everything is salvaged from recycling, and I mean EVERYTHING. The wires, the parts, the breadboard, the meters, even the big variac at upper right! I didn't really need to measure the voltage at the bridge rectifier's output, but I had a 0-300V DC voltmeter on hand, and I was curious to know LOL. On the other hand the interesting phenomenon I discovered with this voltmeter is how the circuits reacts when the supply voltage is brought gradually to 120V. The voltage rises steadily, then past a certain point the current starts rising much quicker than voltage before reaching its final value.After this I was ready to build the lamp itself. I first assembled the LED arrays. I wanted them to illuminate uniformly, unlike many LED lamps I've seen, especially early ones using 5mm LEDs, these were horrible in terms of light distribution!I chose FR2 board material for the structure since I had a piece laying around. It has no copper on it, just a bare phenolic board.The sides, now ready for the installation of the LEDs. Not the best cutting/drilling job I did to be honest xDLEDs installed. As you can guess I salvaged them from something else, a wine bottle cooler to be exact. I used jumpers from an old circuit board to connect them together. There's also a smaller square-shaped 4 LED array that'll go on top of the lamp.Then, the ballast. Because it'll go in the base of an old CFL, I need a round board, or at least something roughly shaped like it.A real prototyping board would probably be better suited than this copper-less board, but again that's what I have available LOL. I made sure the parts had long enough leads so they provide proper support.The ballast assembled. The two holes at the front will support the wires from the base. Otherwise the layout is kinda improvised, and likely not the best. The next one will be better! xDNow I need to figure out how to assemble the parts, especially the LED array. Since it's something that'll be used permanently, I don't want it to fall apart LOL.

author: German_EE
author_rank: Super Contributor
timestamp: July 04, 2014, 12:53:25 pm
content: Nothing wrong with using salvaged parts. I have ten LED bulbs in my workshop and their power supply came out of an old DVD recorder. Sure, most of the outputs are unused, but all I had to do was change one resistor and I had a clean cool-running lighting supply.

author: SeanB
author_rank: Super Contributor
timestamp: July 04, 2014, 05:32:18 pm
content: Nice work Fox.

author: lapm
author_rank: Frequent Contributor
timestamp: July 04, 2014, 06:15:41 pm
content: Salvaged parts was how i got started on electronics when i was kid... Televisions still used throw hole components mainly, etc... Easy to get parts... Somone tossed old tv, i salvaged pcb's from them...As others have sayd, nothing wrong with it as long as they are still in working condition..

author: rob77
author_rank: Super Contributor
timestamp: July 04, 2014, 06:48:50 pm
content: +1nothing wrong with reusing parts if it's safe ! if reusing parts for mains, then pay attention to insulation and safety in general . but definitely use NEW wires for mains (old wires might have cracks in their insulation) + use heat-shrink tubing to minimize the risk of touching the live parts.

author: Derick Freese
author_rank: Contributor
timestamp: July 05, 2014, 04:26:02 am
content: I have kept boxes upon boxes of boards to salvage parts from. You never know when something will have just the right part. Free is best, right?

author: mariush
author_rank: Super Contributor
timestamp: July 05, 2014, 05:30:56 am
content: A few weeks ago I went through the mall and spotted a couple of spotlights in the recycling bin of a store and pulled them out... nice spotlights, phillips mastercolour :http://www.ecat.lighting.philips.com/l/lamps/compact-high-intensity-discharge/mastercolour-cdm/mastercolour-cdm-r111/21287/cat/Shame they only have 5-6000h of bulb life, seem quite complex for a spotlight.But anyway, it's a good thing for me, because i pulled out the bad lightbulb and I'm left with just the nice reflective surface, and the diameter of the hole in the center is just the right size for a nice 10-20w led die. Will make a good flashlight/spotlight for my desk.

author: Vincent
author_rank: Regular Contributor
timestamp: July 05, 2014, 04:50:12 pm
content: Oh, that would make a nice LED lamp reflector!Quote from: Derick Freese on July 05, 2014, 04:26:02 amFree is always best! So far I only had to buy some CD4017s for a project, I could find everything else on old circuit boards, even 555s! I even have two 556s and a 558 if I ever need them

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: July 05, 2014, 04:56:40 pm
content: Quote from: Vincent on July 05, 2014, 04:50:12 pmI used to find lots of stuff in people's trash, and I used to live near the municipal dump. I'd get lots of parts there until they put up a much higher fence and barbed wire.You're in Canada, where do you find your stuff in "recycling"?

author: SeanB
author_rank: Super Contributor
timestamp: July 06, 2014, 09:18:29 am
content: Vince dumpster dives a lot. Look up his lighting page.

author: Psi
author_rank: Super Contributor
timestamp: July 06, 2014, 09:31:56 am
content: Here's my latest homemade LED room lighting.100W warm white LED+PSU from aliexpress for US$23.99 free shipping!Plus a old 15V fan which i added a resistor to so it runs from 5V (less noisy).(yes, it does need the fan, even with that 300W mosfet amp heatsink lol. LED sits at 83degC without the fan and its only rated to 80 absolute max. With the fan it sits nicely at 60CI had planned to open up the PSU and put a pot on the current limit so i could change the brightness.(9000 lumens is pretty high for a room that would normally have a 1500lumen 20W CFL)However the PSU turned out to be IP67 and potted. So 9000lumens it is"My room becomes daylight, destroyer of your retina"I still need to attach a diffuser panel to the standoffs and hide the electronics.At the moment it creates iris spots of death to anyone who's stupid enough to look directly at it.It also casts crazy sharp shadows, which is a bit weird.One word of warning if you attempt this yourself. I shudder to think of the quality in that china PSU when the entire thing with 100W LED is $24. And since it's potted you cant check itI did check if the output is mains isolated though, it is isolated.