Is there a "classic" diode? One that is designed to do only what diodes are
famous for - only allow current to flow in one direction? I'm guessing that
it's the 1N4001 - because that's the diode I see used the most. But I could
also be completely off. What do you think? Thanks!
Michael
The "desert island" question for diodes. Hmmn....
1N400X -- Obvious choice for a first power rectifier diode. Good for 1 amp,
PRV dependent on X (get 1N4007 if you only want to stock one, because its PRV
is 1000V, and you can always substitute a 1N4007 for any of the others.
Inexpensive due to popularity.
1N914B/1N4148 -- These diodes sub for each other, as well as 1N914 and 1N914A.
One of the problems with the 1N400X is that it has a large diifuse die area and
high junction capacitance, and as a result isn't very good at high speed
rectification (anything over about 1KHz). When voltage across the diode
switches, the junction capacitance has to charge up before it blocks current,
and this charge passes through the diode. The 1N4148 is made with a smaller,
much better defined P-N junction, and so has less junction capacitance, and
works well at higher speed. It doesn't have as high a voltage or current
rating (75V @ 150 mA), but is very useful to have. This diode is also called a
"switching diode" or "computer diode". Again, inexpensive due to large volume.
The above would be the first two I'd get a hundred of just to have around in
the parts bin. After that, it kind of depends on where you want to go. The
above diodes are standard silicon. You have germanium and schottky diodes too,
as well as a wide range of currents/speeds/leakage current requirements.
That's why there are so many different kinds.
Good luck.
Chris