On Sun, 12 Dec 2004 09:45:56 -0800, put finger to
keyboard and composed:


I posted a more detailed message in .design and haven't got a response
yet. But anyway, to keep this short and sweet. Is there any trick
that people use to test and diagnose DC tachometers? I have a 4
channel tach that is powered by 24VDC. Each channel has a VCC, Vout,
and gnd. It's supposed to be an open collector output, but when I
connect my external circuit all I get is a steady 24VDC on the Vout
with a lot of noise on top of it. Does this inherently mean
something? Are there any tricks I could attempt to find out what's
going on? Thanks.

I don't know what kind of external circuit you are using, but I would
first test the tacho with a resistor (10K?) between Vout and Vcc.


- Franc Zabkar
--
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