GB1152295A - Improvements in or relating to Switched-Voltage Regulated DC Voltage Supply Arrangements - Google Patents

Abstract

1,152,295. Automatic voltage control. MARCONI CO. Ltd. Jan.30, 1968 [Feb.9, 1967], No.4744/68. Heading G3R. A D.C. voltage regulator comprises a transformer 5 having its primary winding 4 connnected by way of an electronic switch 6, e.g. a transistor, and a primary current sensor 14 to a D.C. supply source 1; a capacitor 9 which is connected across the output terminals 10, 11 of the regulator and which is also connected over a rectifier 8 and a secondary current sensor 15 to the secondary winding 7 of the transformer 5; a sensor 16 responsive to the D.C. output voltage; and on OR gate 13 or equivalent circuitry having its output connected to control the switch 6 and having respective inputs derived from the sensors 14, 15 and 16. In operation, when a voltage first appears across the input terminals 2, 3 the transistor 6 is rendered conductive and current builds up in the primary winding 4 until a predetermined current level is reached, at which value the sensor 14 produces a signal to switch off the transistor; the voltage across secondary winding 7 then rises rapidly and capcitor 9 is charged by the resulting current flow, the secondary current sensor 15 producing a signal to hold transistor 6 "off" all the time secondary current is flowing; when transfer of energy between windings 4 and 7 is complete, transistor 6 will then again conduct, and the cycle will be repeated until the voltage across capacitor 9 reaches a predetermined value, at which point the sensor 16 will produce a signal to render transistor 6 non-conductive. The regulator has an inherent short-circuit protection characteristic, and is able to accept input voltages that are appreciably larger or smaller than the regulated output voltage. The sensors 14, 15, 16 may include transistors Fig.2 (not shown) and the sensor 15 may be constituted by a tertiary winding on the transformer 5 Fig. 3 (not shown)