Ah, the magnificent incandescent diode:

 

Amazing, huh? Pass enough current through something and it'll melt, glow red and/or catch fire! Who woulda thunkit???

 

Aw, you wanna have some fun? Do a little inductive heating! I'm not saying anything more.

 

Many years ago now, when power supplies used neons as voltage references, I was working on an oscilloscope which had no trace. I looked at the power supply board and the first thing I noticed was that the neon was glowing so I thought at least something is working. Then I realised that this 'scope didn't have a neon and the 'neon' was in fact a wirewound resistor glowing a bright cherry red

 

Many years ago now, when power supplies used neons as voltage references, I was working on an oscilloscope which had no trace. I looked at the power supply board and the first thing I noticed was that the neon was glowing so I thought at least something is working. Then I realised that this 'scope didn't have a neon and the 'neon' was in fact a wirewound resistor glowing a bright cherry red

That was the trouble light.

 

Live wire HAS to be the prodigy of our beloved @loosewire

 

Just wait til lightning hits and all the LED devices in your appliances and computers will glow.

 

Many years ago now, when power supplies used neons as voltage references, I was working on an oscilloscope which had no trace. I looked at the power supply board and the first thing I noticed was that the neon was glowing so I thought at least something is working. Then I realized that this 'scope didn't have a neon and the 'neon' was in fact a wirewound resistor glowing a bright cherry red

I once did a design where I used a red LED to drop a power supply voltage down from 5 volts to 3.3 volts. I hand-built a prototype, with the LED on the bottom of the board, and gave it to the software guy.

I should have told him what I did. The first time he powered it up he saw a red glow and quickly turned it off. After some inspection, he got the nerve to turn it back on. I am not sure he ever really forgave me for this.