Introduction: Using LEDs From an LCD TV.
Tools needed:
Side cutters or metal shears. Either are fine, You can even break the boards by hand if you don't mind the rough look.
Sandpaper. I used a disk sander on my lathe, but it removes material very fast.
flux
solder
soldering iron
Wire
Let's use that waste.
Step 1: Cutting/breaking the Strips
It seems the strips are easy enough to break, but cutting them leaves them a bit nicer and easier to handle. Don't make them less than 2" though, the board acts as a heatsink for the LED.
I like 3 inches with the LED in the center since I plan on installing mine in old Halogen lamps. The 3 inches should let me make use of the original reflector and help center the LED.
It's important to note that the LEDs have a glass diffuser stuck to them that cannot be easily removed, and the diffuser makes the light spread out rapidly.
Step 2: Remove Mask (White Paint Stuff) From LED Board
This step is important. You can't use these without removing this material. It comes off easily by hand sanding so might be better to use that.
The disk sander proved to be quick, But also tended to remove the mask, and the board too!
Be careful. This stuff can't be good to breathe in.
Step 3: Prep and Solder.
Rosin flux and solder are required.
Use your favorites because it didn't seem top matter.
After making sure I had enough copper exposed, I painted flux on each "pad"
Flux painted on all strips I had prepared, I soldered a short bit of wire in place.
Step 4: Test and Continue
Each LED seems to have been designed for 9 volts DC. though the seem to handle 12 V DC okay, they get awfully warm.
I wired them up in rows of 6 (Not pictured) and might use them to illuminate my portable Electronics Station : https://www.instructables.com/id/Portable-Electron...
I needed some light for the station and chose to work with these. I think with a "wall wart" 9 V power supply, I can run up to 6 and have quite a bit of light. The remainder will go into the Halogen lamps I spoke about earlier and also use 9 V power warts. Overall I am pleased I was able to get these to work at all, I had tried for quite some time to get them to light up before finally breaking one apart with the goal of testing individual lights.
If anyone knows a way I can make the lights more reliable, Please let me know. I thought about the addition of resistors, but I'm not sure it's necessary. Please, Go vote on my Electronics station!
8 Comments
6 years ago
I have used these recovered lamps in movie poster back lights, and workshop lights:
https://www.instructables.com/id/Free-Luminaire-Fr...
I didn't know or think they could be separated from the matrix board, but I'll have to try that as I have many on hand. I generally use less than 24 volts D.C. to power the full strips, so experimentation on the individual cells is in order, nice Instructable, thanks for sharing.
Reply 6 years ago
Annnnd... I just looked at the 24v transformer (Wall wart) I used.. AC. Ugh, I'm such a moron! Ah well, I have 3 strips left, I think I'll do the same thing you did.
Reply 5 years ago
I do notice anything much beyond 20 volts increases current demand quite rapidly, the sets I have dismantled used a 24 volt switcher power supply output too. ☺
Reply 5 years ago
I was unable to test my power supply. it was damaged along with the LCD. Apparently, the set came from a troubled home.
Reply 5 years ago
Sometimes the voltages are etched onto the p.c. board where the connectors are at, most times not. Trace upstream a bit and look for electrolytic capacitors in the supply lines to the strips, my rule of thumb is if it says 50 volts, it operates at around 24 since doubling the working voltage is a typical good circuit design for caps. ☺
Reply 5 years ago
Hmm, All the electrolytics are voltage side down and have some sort of white glue on them. Silicone I guess. Is there some way to test them for voltage?
Reply 5 years ago
Okay, I'll check for that. I'm currently trying to make an old Server power supply into a benchtop power supply, so I can practice finding them on that! Thanks!
Reply 6 years ago
Perhaps it was just this board but it wouldn't light up with 24 volts. And I didn't want to go higher. I pulled it from a Vizio LED TV