Polarity protect diode


Paid Member
2007-09-15 8:14 am
It depends how much current can flow... but I guess this is a low powered device... so I would suggest a 1N4002/4/7

I'm assuming the diode is across the supply and relies on a fuse or resistor etc blowing or it may be non destructive in operation and be wired in series with the supply.

Mark Johnson

Paid Member
2011-05-27 3:27 pm
Silicon Valley
I recommend the 1N5817. It's a 20 volt, 1 amp, Schottky rectifier. If it's used "across the supply" as Mooly says, it'll protect as well or better than a silicon diode like 1N400x. If it's used "in series with the supply" it will definitely work better than a silicon diode; 1N5817's forward voltage drop is lower, so it'll keep the effects pedal circuits working another 2-3 hours longer when the battery is nearly drained.

Avnet Express sells them for CAD 0.0382, in quantity one: (link). They have 4,400 of them in stock & on the shelf, today.