Use stripped TV as light/backlit sign. Ballast?

[JDC]

Re: Use stripped TV as light/backlit sign. Ballast?

For anyone wondering, I ended up using a 30W 20-36X1W 300mA 60-120V power supply from here:

https://www.ebay.com/itm/High-Power-...8G3bkEQe1zCeuQ

a 36W arrived and it worked. This is good because it's not a good idea to run something like this at its full potential.

For this TV, there was only two wires to hook it up to, but suppose there are 10 wires (5 for pos, 5 for neg)? Would I need 5 of these devices or a 150W power supply?

[budm]

Re: Use stripped TV as light/backlit sign. Ballast?

For anyone wondering, I ended up using a 30W 20-36X1W 300mA 60-120V power supply from here:

https://www.ebay.com/itm/High-Power-...8G3bkEQe1zCeuQ

a 36W arrived and it worked. This is good because it's not a good idea to run something like this at its full potential.

For this TV, there was only two wires to hook it up to, but suppose there are 10 wires (5 for pos, 5 for neg)? Would I need 5 of these devices or a 150W power supply?

It depends on how the LED strings are connected, most of them are connected in series to form one large string, but some one them will have individual controller for each string so you need to look at how the LED strings are connected. If the each LED current is rated at 300 mA and you know the Vf of the LED then you can calculate how power power each and so you will know what the power supply requirement will be needed.
BTW, do you use any current limiter fro driving the LEDs? You should.

[JDC]

Re: Use stripped TV as light/backlit sign. Ballast?

Let's use a real life example. I have an RCA 50LB45RQ. 8 wires altogether (4 pos, 4 neg). If each strip takes 30W to light up, would I need 4 of the same power supply or could I use a 120w+ one?

http://www.shopjimmy.com/toshiba-v50...s-8-strips.htm

[budm]

Re: Use stripped TV as light/backlit sign. Ballast?

Each strip has 11 LED so that will be 11W per strip since typical backlights LED is about 1W, you go by what the current requirement and the Voltage requirement to get the LED to work, so I doubt that each strip takes 30W of power.
LED is the current device, it need to be high enough Voltage to bias on the LED for the current to start flowing.
You will need at least current limiter resistor for each string if you are going to connect the strips in PARALLEL, or just one resistor if connected in series.
So the power requirement for the 8 strips with 11 LEDs per strip will be 88W so you will need 100W if you plan to drive them at full 1W but I would not do that, I would drive them at 1/2 to 3/4 W instead to prolong the life of the LED. What ever power requirement is you will add 20% on top of that for the power supply power.

[JDC]

Re: Use stripped TV as light/backlit sign. Ballast?

Awesome, that's the answer I was looking for. Thanks, bud!

[sordids999]

Re: Use stripped TV as light/backlit sign. Ballast?

Maybe a silly question but what do you guys do with the led diffuser and sheets once you strip a tv with a cracked screen ?
It's a shame to bin them or maybe there's some use for them on other projects ?

[budm]

Re: Use stripped TV as light/backlit sign. Ballast?

I use the 60 inch sheet for cat litter boxes wall liner.