GB732749A - Pulse generator for electric fences - Google Patents

Abstract

732,749. Supplying electric fences. CHRISTENSEN, F., [trading as REOFON]. July 13, 1953 [July 31, 1952; March 31, 1953], No. 19409/53. Class 38 (4). [Also in Group XL (c), An A.C. operated pulse generator for energizing a fence comprises a transformer through the primary winding of which the A.C. current is periodically caused to flow to generate a high voltage pulse across the secondary winding to which the fence is connected, the time of commencement and ending of the current flow being dependent upon the instantaneous value of the A.C. voltage. Fig. 1 shows an A.C. operated pulse generator in which the thyratron 5 conducts when the instantaneous value of the A.C. voltage supplied at terminals 3, 4 reaches a pre-determined value and capacitor 11 is charged by the voltage produced across the rectifier bridge 10 so that when the instantaneous A.C. voltage of the supply falls below a given value thyratron 5 is extinguished. During the period when tube 5 conducts a high voltage pulse is produced across the transformer secondary winding 2 which is connected with the fence to be energised. Capacitor 11 slowly discharges through resistor 12 so that when the instantaneous value of the A.C. voltage again reaches a pre-determined value tube 5 fires and the cycle is repeated. If necessary a small A.C. voltage may be introduced at 13 to cause tube 5 to strike. The transformer is constructed to have only a small difference between its idling and short circuit currents and fuse 14 interrupts the current in winding 1 if owing to a defect the current continues substantially beyond one half cycle. In a modification, shown in Fig. 2, the pulse generator comprises an A.C: operated blocking oscillator using a thyratron 5 so that the rectifier bridge of Fig. 1 is dispensed with.