GB1089902A - Improvements relating to electrical pulse generating arrangements - Google Patents

Abstract

1,089,902. Pulse generating circuits. ASSOCIATED ELECTRICAL INDUSTRIES Ltd. Aug. 31, 1964 [June 12, 1963; Aug. 1, 1963], Nos. 23429/63 and 30597/63. Headings H3P and H3T. In a pulse generator of the kind in which a pulse forming network PFN is charged via the primary winding LP of a transformer and then discharged via a load R1 so as to generate a pulse, the pulse amplitude is stabilized by connecting a capacitor C across the transformer at an instant during charging when the PFN is charged to a predetermined voltage. The discharge circuit of the capacitor includes the secondary winding LS and a rectifier D2 arranged so that the voltage induced in the secondary winding determines the datum to which the capacior is discharged through rectifier D2. As described, the PFN is charged from a supply D via winding LP and diode D1 and subsequently discharged through a load R1 (such as a linear accelerator) when the thyratron V2 or a semi-conductor controlled rectifier is triggered. During each charging cycle when the PFN is charged to a predetermined voltage, the voltage at the junction of R2, R3 becomes sufficient to operate a trigger circuit G which operates a thyratron V1 or semi-conductor controlled rectifier so that capacitor C is connected across winding LP so as to divert energy from the charging circuit and prevent further charging of the PFN. Capacitor C is discharged via rectifier D2 during the next cycle, the charge remaining C being determined by the voltage induced in the secondary winding LS. The surplus energy is returned to the supply D. The potential divider R2, R3, R4 may alternatively be connected to the cathode of rectifier D1. In Fig. 5, a pair of capacitors C4, CS are used to couple the primary and secondary windings LP, LS so that the transformer behaves as an auto-transformer with low leakage inductance. Thyratron V1 may be replaced by a vacuum tube.