A Vacuum-Tube Voltage Regulator for Large Power Units

A new voltage regulator is described, suitable for large power units of standard construction. This regulator uses vacuum tubes as the controlling element, in place of vibrating contacts that have hitherto been employed. The voltage variation is less than 0.1 per cent when the load is gradually changed from no load to a little above full load. When this regulator is applied to d-c unit, some a-c source is necessary to supply the B-eliminator which is an essential part of it. The voltage of this a-c source, however, need be only fairly constant; it may safely vary by ± 3 volts (in the case of a 110-v source) without causing more than ± 0.1 per cent variation in the d-c line under regutlationt. When an a-c unit is to be regulated, on the other hand, the same unit may supply the B-eliminator.