GB521828A - Improvements in and relating to voltage-regulating apparatus - Google Patents

Abstract

521,828. Automatic control systems. MAYO, C. G., and WALKER, H. S. Nov. 29, 1938, No. 34799. [Class 38 (iv)] Voltage.-The voltage of a point 17 supplying a variable load (not shown) from a source 9 is maintained constant by a saturable inductance the degree of saturation of which is dependent upon the difference between the voltage at 17 and that of a constant reference voltage derived from a source 19 loaded lightly with a constant load. Voltage stabilizing slow-discharge tubes 27 ... 30 shunt a potential divider 24 ... 26 and an adjustable portion of this constituting the reference voltage is connected in series with a diode 35 and the saturating winding of an inductance 37 across the load circuit voltage. Current variations in this circuit are proportioned to the difference between the two voltages. and determine, the current in the inductance. The potential across a fixed resistance 39 in series with the inductance controls the impedance of an amplifying tube 45 the current through which saturates a further inductance 47 controlling the potential across a resistance 55 which determines the potential applied to the grid of the series connected valve 13 to correct the load circuit voltage. Ganged switches S<SP>1</SP> . . . S<SP>4</SP> enable simultaneous adjustment of load circuit and reference voltages. Grid bias ,for the amplifier 45 is provided by a choke 48 and resistances 50, 51; its screen grid potential is stabilized by a slow discharge tube 52. The potential changes in resistances 39 and 55 are transferred by rectifying arrangements to the grids. of their respective valves 45, 13. The reference potential may be a dry battery.