At 09:39 PM 5/6/2009, Scott Daniel  - Turbovans wrote:
>a new Bosch, and using a digital volt meter......
>the voltage was going from about .2 to .8 volts very, very fast.
>Like several swings in voltage change  or range, per second.
>I had never bothered to check a new one much.....and boy, did this
>one change voltages fast.

Hi Scott -- unfortunately, with a digital meter of the usual type
it's very tough to see what's really going on, only that something
is.  This is because most digital meters use a technique called
"dual-slope integration" to develop the reading.  They typically
generate a new reading about 2-3 times a second, and use a
significant fraction of that time to sample the input signal; so when
the input is changing the results appear somewhat random.  The ideal
way to measure is with a scope, but an LED bar-graph display driven
by an LM3914 chip, like Ken's little gadget, is a very good
alternative for this particular signal.

Cheers,

  --
David Beierl - Providence RI USA -- http://pws.prserv.net/synergy/Vanagon/
'89 Po' White Star "Scamp"