I request another topic: Dual Use Meter. This is the case where a single meter is used to display amps and volts. Typically, there is a switch between uses. This usage is typical in rectifiers used for cathodic protection and in airplane pilot's panel. Your articles on ammeters and voltmeters helped me to design my own circuit to replace a meter which failed.

wonderness

 

Is this dual use meter different from a multimeter that can measure volts, current, and resistance?

 

Yes, similar to multimeter. Multimeter has volts, amps, ohms, and others. In each type, it usually has ranges.

The fixed dual use meter has two types and one range in each type.

The excellent writeup in "All About Circuits" nicely describes multi-range volts and multi-range amps. It also gives good insight to use a voltmeter as an ammeter as well as an ammeter as a ammeter.

My desire is to read the discussion concerning the working together of this one analog meter with its mechanical and electrical characteristics, to correctly display volts and amps. For the dual use meter, a toggle switch enables one feature then the other. For a multi-meter, a rotary switch as well as movement of the test lead from one connection to another (volts/ohms then amps).

Thank you,
wonderness