| 摘要 |
904,226. Systems depending on two or more sources. STANDARD TELEPHONES & CABLES Ltd. Jan. 16, 1959 [Jan. 21, 1958], No. 1633/59. Class 38 (4). A switching arrangement for substituting without interruption a battery 3 for the D.C. output of an A.C. rectifier unit 1 supplying a load 2 comprises a transistor 5 which is unblocked by means of a central unit 6 when the rectifier output fails. The unit 6 measures the voltage difference between the rectifier output and the battery and unblocks the transistor, which arrangement also allows the battery to supply peak loads. After it has unblocked the transistor may be bridged by a relay contact (not shown). A circuit may be provided to prevent the transistor unblocking when the battery is in a discharged condition. A second rectifier unit 4 is provided to charge the battery. |
