Amplifiers (and voltmeters)

[Dick Linn]

Take a look at the bottom of the page for "Analog Milliamp Meter Used as Voltmeter". It shows a milliamp meter being used as a voltmeter. This is what Don was talking about.

http://ourworld.compuserve.com/homep...m#1mameter.gif

Also see:

http://www.engineersedge.com/instrum...l_movement.htm

http://www.electronicstheory.com/html/e101-20.htm

And this is just pretty neat: http://chem.ch.huji.ac.il/history/arsonval.html

If you are in New York City, there should be a number of electronic/electrical junk places around. I used to see stuff like this in some of the surplus shops on Canal Street between Chinatown and Little Italy.

Another Sperry, $8.99 with shipping: http://www.meritline.com/aw-sperry-s...ultimeter.html


You might find that the cheapest way to get analog meter movements is to buy an entire voltmeter and gut it. For example, here's a Sperry meter for $3.95. plus shipping. If you buy multiple units, there's no extra shipping. Maybe you can buy one at Home Depot first to see if it is viable. It might be difficult or impossible to get the bezel off (intact) to put on your own scale.

http://cgi.ebay.com/Sperry-Analog-Mu...3286.m14.l1318

Here's another link to them: http://stores.channeladvisor.com/Dig...itemid=2386743