How to reduce LED lamp DC powersupply voltage to power TV backlight LED's

[robsims]

Hi, i have a TV with a damaged powersupply board. The powersupply board doesn't output power to  the backlight LED's. I have a powersupply from a LED lamp that outputs 161 volts DC. I want to use this powersupply to power the LED backlights of the TV. The TV has 45 backlight LED's,  so the  voltage of one LED will be 161 : 45 = 3.6 Volts DC.  I want to lower the powersupply's 161 volts DC output so that every LED gets 3 Volts DC.  My quesion is what method can i use to lower the output voltage of the powersupply?

[mariush]

That's not how it works ...

Leds have a maximum current and a forward voltage that varies with temperature of the leds and the current.
For example a cold led may have a forward voltage of 3.2v , and a hot led may have a forward voltage of 3.1v ...

The led driver of your monitor is configured for some maximum current, for example 80mA ... it starts to output some voltage (for example if all leds are in series, let's say 45 leds x 2.8v =  125v) and then as it monitors to current, it raises or lowers the voltage to keep the amount of current through the leds at 80mA.

Your lamp driver may have the current set to 100mA or more, or may be much lower current... point is you could damage the leds by giving them too much current.

A better option would be to use a universal led driver board from eBay or some place, that supports the output voltage range and current range you need.

You may also want to double check, those 45 leds of your TV may split in 2 or 3 separate chains  (ex 3 x 15 leds), because reducing voltage from 110v / 230v AC down to around 45v is more efficient than potentially boosting it to 150v+