"meirman" wrote in message
...
I almost can't believe it, but after 35 years, I still get confused
about positive and negative. Sorry to bother you, but I just can't
remember.

I'm replacing a bridge rectifier with 4 separate diodes, and I know
where the negative should be. If I put one diode on one AC wire, and
another diode in the opposite direction on the other AC wire, and if I
set the VOM on 200V DC, and I put the common/negative/black lead from
the voltmeter on the unconnected end of one diode, and the
positive/red lead on the other diode, and the needle moves to the
right (I get a positive reading) does that mean the diode with the
black wire on it is putting out negative?

That's what I think, but I'm not sure.


If I went by the silver/grey band on one end of the diode, would that
end be the positive or negative end?

These are all laid out parallel to each other and taped together, with
narrow white paper tape on one end, and red paper tape on the other.
This means that the end with the red tape puts out positive voltages,
right?

Thanks.

Meirman

If emailing, please let me know whether
or not you are posting the same letter.
Change domain to erols.com, if necessary.



Connect two diodes together at the striped end, that'll be your positive
output, connect the other two together at the non-striped end, that'll be
your negative output, now connect the two free pairs together in the middle
and apply AC across those.