POWER SUPPLY

摘要

A power supply unit has an overdischarge detection circuit for detecting overdischarge of a power source, an overcurrent detection circuit for detecting overcurrent, and a stopping circuit for stopping overdischarge or overcurrent in accordance with an overdischarge detection signal or an overcurrent detection signal. The power supply unit is further provided with a delay circuit to prevent the overdischarge detection circuit and the overcurrent detection circuit from being activated erroneously by external noises. This delay circuit provides a variable delay time so that the delay time will be longer when overdischarge is detected than when overcurrent is detected. This makes it possible to stop overdischarge and overcurrent without fail. <IMAGE>