Circuitry for testing generator output

Claim 1

Means measuring the short circuit output current of a generator with an excitation voltage proportional to the rated output voltage of the generator, comprising a circuitry including an ammeter in circuit with a generator, an induced element of said generator being in series with the internal impedance of said generator and with said ammeter, short circuiting said generator, said circuitry including an appropriate voltage source, said voltage source providing an excitation voltage applied to the field of said generator, means causing said excitation voltage to be a predetermined proportion of the rated voltage of said generator, whereby the output current of said generator passes over said ammeter as a linear function proportional to said field excitation voltage, said ammeter being calibrated to convert the reading of said current passing thereover into a direct reading of the full output current of said generator under load, said circuitry including an absolute value comparator referenced to a common voltage source, and a switch selectable attenuator in connection with said comparator monitoring the output voltage of said generator.