You almost never hear of a DC Watt Meter – one just does some mental math with Volts and Amps at the back of one’s head. An AC Watt Meter, on the other hand, can by pretty useful on any workbench.

Abstract: There are two general classes of large capacity watt-hour meters, alternating-current and direct-current. The meters used for alternating current are almost invariably of the induction type, ...