GB928210A - Transistor-controlled power supply - Google Patents

Abstract

928,210. Automatic voltage control. NEDERLANDSE ORGANISATIE VOOR TOEGEPAST - NATUURWETENSCHAPPELIJK ONDERZOEK TEN BEHOEVE VAN NIJVERHEID, HANDEL EN VERKEER. Feb. 8, 1961, No. 4693/61. Class 38 (4). In a voltage regulator of the series or shunt transistor type a D.C. load is fed over a rectifier from an A.C. supply source and the transistor is protected against overload by a variable impedance connected in the input to the rectifier. As shown, a variable impedance 11 has a threelegged core with a winding W 1 on the inner leg, in series with the input to a rectifier 12, and series-connected windings W 2 and W<SP>1</SP> 2 on the outer legs in parallel with a load 9 the voltage V across which is maintained constant by means of a series transistor 8. Under normal operating conditions a large direct current flows through the windings W 2 , W<SP>1</SP> 2 and the impedance 11 has a low value. If a short circuit should occur no current flows through these windings and the impedance is at a maximum whereby current from the supply source is limited and excessive dissipation of power in the transistor 8 is avoided. A shunt transistor regulator is described with reference to Fig. 2 (not shown), where the variable impedance is controlled by the current through the load, the impedance increasing as the load current decreases. Specification 831,511 is referred to.