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Looking for a low voltage LED (mouse LED replacement) Answered

I ran into a problem when changing the LED of a mouse. It seems to output only 1V, and that, of course is not enough to drive the 3V LEDs which I currently have in stock. The problem is, I can't find any LEDs of my preferred color (yellow, green or white) that would be OK with 1V. Closest thing I can find is diffused 1.5V 3mm yellow LEDs, but I doubt that'll do the trick, as the original is 5mm.
Any ideas where I could find a LED that'd match my requirements?



3 years ago

There really is not a lot you can do in terms of getting a low voltage LED of a short wavelength. IR LEDs generally have a 1.2V drop for them, red LEDs are higher, at about 1.8-2V, and as you work your way up to orange and amber LEDs, the voltage drop is again higher, 2-2.4V typical, and then the GaN/InGaN LEDs (the ones that are like neon green and bright blue/UV) can require 3V-4V respectively.

A joule thief may be a simple solution if what you say about the voltage is really true. However, I have my doubts that the output to the LED is 1V Max. It might be 1V average or RMS, but I bet it is driven from a boost converter of some thing because 1V is only enough for IR Leds.

The Led is probably being driven by a pulsed signal (Pulse Width Modulation)

Even though you may read it a 1.5v chances are it's actually 3.2V(Ish) turned on and off a few thousand times a second, Illuminating the Led to full brightens for just a moment then Turing it off again.

Your mouse could be using this pulsed signal to take a series of pictures Really quickly, and using that info to track movement.

**Have you tried simply hooking up a standard Led to it? be sure to test it with a 220 - 100 Ohm resistor just in case the mouse won't handle it. Also if you wanted to change the color... why not just add some extra Led's? seem simpler :)

Good Luck !

LED voltage is a function of their colour, there's not a lot you can do about it. You can try finding the current limiting resistor on the circuit board and changing that. Do you know if the sensor will work with an LED of another colour ?