Question about "Voltage Sag" / "Dying Battery Simulator" & LED's

[mr.adambeck]

I'm putting a voltage sag, from The beavisaudio.com site (awesome site!) and I'm wonering: If I put the sag AFTER the LED, would the LED stay fully lit when the pedal is being sagged?  Otherwise, the sag causes the LED to dim.



Also, anyone know what size Resistor goes before an ultrabright LED?  It's blue, if that helps. 

[WLS]

...
Also, anyone know what size Resistor goes before an ultrabright LED?  It's blue, if that helps. 

You can breadboard your led kind of like your picture. Use the pot to get the brightness you desire. Then measure the resistance of the pot with a DMM and that will tell you what resistor to use. 

Bill