silverstat regulator

silverstat regulator

[′sil·vər‚stat ′reg·yə‚lād·ər]
(electricity)
Multitapped resistor, the taps of which are connected to single-leaf silver contacts; variation of voltage causes a solenoid to open or close these contacts, shorting out more or less of the resistance in the exciter circuit as a means of regulating the output voltage to the desired value.