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Arfa Daily
 
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Default SMT Diode Identification


"Michael Kennedy" wrote in message
. ..
I was at the local surplus dealer and they had the zener diodes organized
by zener voltage. Would a 8v2 be a 8.2v zener?
Thats what I got and it seems to ohm very close to what the good zener
ohms.

The actual part number for the zener that I got is 1N5237b738.

Thanks for all the help Arfa


Yes, 8V2 is eight point two volts. It is the de facto way of writing it
these days - at least this side of the pond - and saves any confusion with
flies crapping on the page, or your glasses needing replacement. It is very
easy for a decimal point to disappear as a result of poor printing, or one
to appear because of that fly ...

It is also the standard way of writing resistor values - 4k7, 1M2 for 4.7k
or 1.2M ( see how easily that 4k7 could be read as 47k ). Capacitor values
appear like this too. 6u8 for 6.8uF, 2n7 for 2.7nF, 0u1 for .1uF, 3p3 for
3.3pF etc. On some schematics, you will find voltage checking points marked
in the same way.

The resistance of a zener diode, is no indication of its zener voltage,
however. There are some exceptions, but in general, any small low voltage
zener will read the same, ohms-wise, as any other, and indeed, any other
ordinary diode, because this is all that they actually are. All diodes
exhibit zener effect when reverse biased. It's just that with zeners, the
doping of the semiconductor material has been calculated to produce
predictable and accurate reverse breakdown voltages.

Arfa