On Tue, 24 Nov 2009 14:46:01 -0600, John Fields
wrote:

On Fri, 20 Nov 2009 14:26:29 -0600, John Fields
wrote:

On Fri, 20 Nov 2009 10:07:58 -0500, "Bill Garber"
wrote:


"John Fields" wrote in
message ...
On Fri, 20 Nov 2009 13:53:46 +0000, Ian Jackson
wrote:

In message ,
John Fields writes
On Thu, 19 Nov 2009 20:21:53 +0100, "Arie de Muynck"
wrote:

"John Fields"
Arie de Muynck...

John Fields ...
Ian Jackson ...
Is that really a 5 microamp meter, or actually
just a meter with a 5 microamp FSD scale?
It's real. :-)

And a real beauty it is.

What is the internal resistance,
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Can't find the spec but, measured here, about 6000 ohms.
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AKA how much uWatt does it need?
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Since P = I²R = 5e-6A * 6e3R = 3e-2W = 30mW for full-scale deflection.

Uh?

P = I²R = (5e-6A)^2 * 6e3R = 150 nW full-scale.
How about energy efficient...

Aarghhh!!!

Right, thanks. :-)

JF

You can probably make the needle move simply by staring hard at it!

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Not quite, but if I hook up a test lead with steel alligator clips to
one terminal and one with copper clips to the other, I can wet my
fingers and squeeze the unconnected terminals and get about 2µA into the
meter.

JF

Dare we ask to see this? ;-)))))

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Sure!

I've been wanting to make a little video anyway, and this seems like a
perfect opportunity, so I'll post it here in a day or so...

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Well, I made the video, but it turned out to be 200MB so I can't post it
here through Giganews. :-(

Looks like I'll have to learn how to do it on YouTube...

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That was easy! :-)

http://www.youtube.com/watch?v=ixlqM4Gx4IM

JF