| 摘要 |
PURPOSE:To control abnormal rise of an output voltage due to an abnormal control loop to a minimum by providing an output voltage detector for allowing the supply of a driving voltage of a gate electrode from a second rectifying and smoothing circuit to an FET only if the output voltage of a first rectifying and smoothing circuit falls within a predetermined voltage range. CONSTITUTION:An output voltage detector 21 is turned OFF at time tt, the gate of an FET 11 is started, a charging current is fed to a smoothing capacitor 7, and a voltage drop occurs across a load 13. The level of the voltage drop is proportional to the difference of the output voltage of other redundancy power source 14 if other conditions are the same. When the output voltage of a power supply is abnormally raised to an overvoltage detection point at time t4, a system is switched to a stop mode. The highest arrival point of the output voltage is varied at responding time td from a detection point t5 to the stop of the system, and the highest voltage is raised as the time is delayed longer. |
