Subject: Zener Diode ID
From: "Ronak Shah"
[email protected]
Date: 11/30/2004 8:57 AM Central Standard Time
Message-id: <
[email protected]>
This might be the weirdes questen here....
Well I picked up a miex lot of components and it has about 5-6 Zener
Diodes... (thats what i think they are) Well the problem is they are sooo
tiny and hence I cant read the values.. is there a way I can find out the
values? I mean ID the diode....
Now that I think of it... are they even Zener diodes? I know 1N914 comes in
glass case too...
Is there a way I can find out what this is and what values it holds....
Hi, Shah. No weird questions here. If they're in a glass case, they're
probably either signal diodes or zeners. If they're zeners you can usually
tell the wattage by the size (400mW zeners are smaller than 1W zeners). The
tiny ones are usually the 400mW ones.
One thing you might try is cobbling up a 30V power supply, and putting the
back-biased diodes (Device Under Test, or DUT) in series with an appropriate
resistor. If they're standard diodes, all the voltage will be across the
diode. If they're zeners, there will be a zener voltage across the diode, and
the rest will be impressed across the resistor. Note that this will not be a
good solution for higher voltage zeners (they will look like standard diodes)
or schottky diodes (which can break down at 20V, depending). But, if the
choice is between standard silicon signal diode or low voltage (less than 24V)
zeners, this will give you a pretty good start.
Remember to start with a higher resistance value to avoid smoking the zener,
and after getting an initial indication of zener/avalanche, choose a more
reasonable resistance to test at something like half rated wattage. (power =
volts * current).
___
.--|___|---X----.
| R |
| |
| |
--- DUT -
-30VDC ^
| |
| |
'----------X----'
created by Andy´s ASCII-Circuit v1.24.140803 Beta
www.tech-chat.de
Good luck
Chris