| 摘要 |
<p>1,127,909. Stand-by supply arrangements; converting. TRW. Inc. 30 Dec., 1965, No. 55255/65. Headings H2F and H2H. A stand-by supply system comprises an A.C. source 12 which normally feeds a load 11 and charges a battery 20 through a circuit including a transformer 23, silicon controlled rectifiers 25, 26, diodes 33, 34 and an inductor 31. When the voltage of source 12 falls below a predetermined value, a relay 14 actuates its contacts 13, 15-18 to operate members 20, 23, 25, 26, 31 as an inverter and so supply the load 11 through a filter 21. The charger drive circuit 24 and inverter drive circuit 41 are conventional and are isolated by diodes 37-40, respective pairs of which each form an OR gate. When charging battery 20 the voltage across transformer taps 27, 36 or 28, 35 is applied to members 25, 34 or 26, 33, and rectifiers 25, 26 pass current pulses whose duration and magnitude are determined by the difference in phase between the firing pulses from circuit 24 and the A.C. across the winding 30. During inverter operation diodes 33, 34 protect the rectifiers 25, 26 from high reverse voltages, these rectifiers being turned off by a commutating capacitor 52 whose charging rate is reduced by the inductor 31.</p> |
