Programmable Digital Two-Channel Function Generator for Testing Power Meters

A digital two-channel generator has been constructed for testing wattmeters with distorted waveforms and various power factors. The two staircase functions from the generator are fed into the wattmeter via impedance converters with low-pass filter characteristics. The performance was studied with respect to the consequences of ideal and real staircase functions, the use of filters, and impedance converter properties. Four different wattmeters, normally used for the determination of ac magnetic losses, were tested for their suitability for this purpose.