GB1043409A - Improvements relating to controlled rectifier circuit arrangements - Google Patents

Abstract

1,043,409. Semi-conductor rectifier circuits. WESTINGHOUSE BRAKE & SIGNAL CO. Ltd. May 28, 1964 [June 10, 1963], No. 22990/63. Heading H3T. A capacitor-inductor circuit is coupled to the output circuit and to the gate circuit of a semi-conductor controlled rectifier to supply a reverse bias to the gate electrode when a rising voltage occurs on the supply line so as to prevent false firing of the rectifier. In Fig. 1 supply voltage surges are transmitted to the gate in reverse polarity through a capacitor C1 and a transformer, the secondary of which may be in parallel with the gate circuit as shown or in series with it (Fig. 2, not shown). When rectifiers are connected in series the transformer may have a single primary winding separate secondaries for the different-rectifiers (Fig. 4, not shown). In an alternative circuit (Fig. 3, not shown) the capacitor is connected across the rectifier and an inductor is connected in the common part of the gate and output circuits.