| 摘要 |
PURPOSE:To function a breaker of a DC circuit back to a function as a breaker after operating it as a short time step-down chopper by operating the breaker as the chopper and stopping the chopping operation when it approaches the voltage of other inverter during ordinary operation, thereby continuously energizing it. CONSTITUTION:This system has a frequency divider 201 for dividing the frequency of a high frequency pulse signal A to chopper operating fequency, a flip-flop 202 set by the output signal B of the frequency divider 201, presettable counters 203, 204 having BCD code input/output, and a comparator 205 for comparing an discriminating the two BCD code signals. The flip-flop 2102 is set by the output signal C of the comparator 205 to produce an ON signal D at the chopper operation time. Simultaneously, a monostable multivibrator 206 is triggered to form an OFF signal E at the chopper operation time. On the other hand, the output signal c of the comparator 205 is fed to the pulse counter input of the counter 203 to count it up, and the output BDC code is counted up. |
