Cloggy Saint wrote: ↑Thu May 28, 2020 4:52 pm
Do you have a link for where you got the LED? The one I have is too big. And doesn't work.
LEDs have a forward junction voltage, which needs to be reached for the diode to light up. Unfortunately, white LEDs have a junction voltage in excess of about three volts, so they won't light on the two cells (1.2 volt each = 2.4 volts), that you can get inside an E30 torch case. Most other colour LEDs have a lower junction voltage, so will light on 2.4 volts.
There's a little voltage multiplier/ringing circuit that can be used with LEDs to increase the voltage seen by the LED, with a peculiar name that escapes me, and given the apparent performance of that LED bulb in the link, I suspect that it has this ringing circuit built into the case, so is much more than just a LED.