GB642673A - Improvements in or relating to voltage regulators - Google Patents

Abstract

642,673. Automatic voltage control systems. WESTERN ELECTRIC CO., Inc. July 25, 1947, No. 20132. Convention date, July 14, 1944. [Class 38 (iv)] In voltage regulators of the type comprising, in series with the load, a valve controlled by an amplifying valve, the amplifier control voltage is the resultant of a voltage proportional to the load voltage opposed by a voltage proportional to the load current and opposed by a stabilized reference voltage; further, the anode/cathode voltage of the amplifier valve'or the stabilized reference voltage may be made greater than the load voltage. The output voltage of rectifier 10 is stabilized by a series valve' 12 controlled by a pentode 11 connected, in series with a load 19, across the output. The screen grid of valve 11 is supplied at a reduced voltage by the output of a second stabilized rectifier 26. The control grid is subject to the voltage across resistance 25 (proportional to load voltage, opposed by a small voltage across resistance 17 (proportional to load current) and also opposed by a portion, tapped off potentiometer 23, of a reference voltage derived from rectifier 76 and stabilized by a discharge tube 21. A gas-filled tube 90 connected between anode and cathode of valve 11 prevents the load voltage rising to an excessive value. The output voltage of rectifier 26 is stabilized by a series valve 28 controlled by a valve 27 having its anode load connected to one side of the output and the cathode connected via potentiometer 39 and resistance 37 to the negative side of the auxiliary supply derived from rectifier 76. thereby increasing the anode/cathode voltage. The screen grid is supplied from the relatively positive side of the auxiliary supply. The control grid is subject to the voltage across resistance 36 having variations corresponding to load voltage changes, opposed by the voltage across resistance 33 (proportional to load current) and also opposed by a reference voltage derived from the auxiliary supply, applied across potentiometer 39 and resistance 40, and stabilized by a discharge tube 38. The output voltage of rectifier 51 is similarly controlled by a series valve 53 and amplifying valve 52 except that the cathode voltage of valve 52 is fixed whilst the control grid voltage is adjustable.