1N4002 Diode Substitution?
- Thread starter joelorigo
- Start date
Nostradoomus
Well-known member
Is it a polarity protection diode? 1n5817 if it is
joelorigo
Well-known member
I'm not knowledgeable enough to answer that question. The project is a clone for the Boss FA-1 FET Amplifier from Aion
Yes it's the protection diode - it "protects" the rest of the circuit if you plug it in with reverse +/-9VDC
1N5817 is fine
Just FYI: the 1N5817 lets more current through than a 1N4002 which is why it's popular as a surge protection diode. The 1N4002 is pretty much the same in a pedal circuit as using a 1N4001. Or 1N4003, 1N4004, 1N4005... I believe it's just the voltage ratings which are different.
In tube amps 1N4007s are often used in quads as rectifiers. They look a lot like a 1N4001 but have much thicker wire.
In tube amps 1N4007s are often used in quads as rectifiers. They look a lot like a 1N4001 but have much thicker wire.
joelorigo
Well-known member
OK. And in this case, "polarity protection" is about accidentally plugging in a center positive adapter, correct? So if I never do that, the difference in the diode doesn't matter?
On the other hand, if I do accidentally plug it in with a center positive, even though the 1N5817 lets more current through, the circuit will still be protected?
Chuck D. Bones
Circuit Wizard
That kind of shunt diode protection does nothing to limit the fault current. If you connected a 9V batter backwards, you'd smoke some traces on the board. Most pedal power supplies limit the current to a safe level. Any diode rated for 1A or higher will suffice. That includes the 1N4xxx series, 1N5806, 1N5817, etc. Small signal diodes like 1N914, 1N4148, BATxx, could fail before the power supply goes into current limit. I prefer the series protection that PedalPCB employs.