Instructables

Can I run an LED at a high voltage?

I want to create a discharge indicator for a capacitor bank. I planned to do this with a simple switch-resistor-LED setup.

My LED has a forward voltage rating (as well as max reverse), and it has a max current rating. My capacitor bank is 330V, so once I calculated the resistance I needed for the 20mA I plan to use, I created a board of resistors that will give the required current and dissipate >10W.  My 20mA is 10mA less than my LED's max current rating. Its forward voltage is 2.8V.

Even though I have proper current levels and power dissipation, will the 330V burn out the LED? I didn't think it would, but I wanted to look around and make sure. I couldn't find any definite answers.

Thanks!

No it won't burn out the led. The resistor will be doing a lot of work though.....
+1

Perhaps consider a high dc panel voltmeter to be sure what the bank's voltage is at.
Definitely. The high volts and high resistance makes this thing essentially a pretty good constant current source !! So the LED won't vary in brightness much at all.....