To provide a power supply protective device wherein excess voltage is not transmitted to a loading side for a moment, even if the excess voltage exceeding rating is applied, and does not exert influence on the loading side at all, regarding a power supply protective device having excess voltage protective function.
The power supply protective device is provided with a rectification smoothing circuit 1 which is arranged in parallel with a power supply line, a voltage detection circuit 2 for detecting voltage of input voltage which is rectified and smoothed by the rectification smoothing circuit 1, and a relay 5 and an inrush power supply protective circuit 4 which are arranged in series to the power supply line. Detection result of the voltage detection circuit 2 is transmitted to the relay 5 and the inrush power supply protective circuit 4 through a delay circuit 3.
Tomoyasu Sakaguchi
Hiroki Naito