GB585464A - Improvements in or relating to electric power supply systems - Google Patents

Abstract

585,464. Electric currents converting. MACKAY, D. M., and WRIGHT, C. S. Nov. 26,1943, No. 19749. [Class 38 (ii)] An electric power supply unit for feeding a load during one of an even number of successive half-cycles of an A.C. supply, includes one or more time delay networks having time delays of an integral number of half-cycles, connected to the A.C. supply so that energy for feeding the load during the one half-cycle is evenly distributed throughout all of the successive half-cycles. In the embodiment shown in Fig. 1, one half S1 of the secondary winding of a supply transformer P is directly connected to rectifier R1 and load condenser K, while the other half S2 is connected to a second rectifier R2 having the same load K through a network N having a time delay of one halfcycle. Thus, both rectifiers conduct simultaneously during one half-cycle to charge condenser K to a voltage equal to that across one half-winding S1 or S2, the energy being drawn from windings S1 and S2 during successive half-cycles. In a modification, Fig. 2 (not shown), the two rectifier circuits are connected in opposite senses across the whole of the transformer secondary, and separate load condensers having a common terminal are provided. The output voltage, occurring during alternate half-cycles, is at twice the supply voltage. In Fig. 3, a single rectifier R and load K are connected across points ZX of a three-terminal network N having a delay of one half-cycle. Since the voltage across YZ is 180 degrees out of phase with the voltage across XY, the voltage across XZ is twice that across the secondary S of the supply transformer, and gives a rectified output of this value during alternate half-cycles although the energy is drawn from the supply during successive halfcycles. By combining three such networks, a voltage of four times the supply voltage and occurring during every fourth half-cycle may be obtained (Fig. 5, not shown). The rectifiers may be replaced by spark gaps.