Direct -current input surge suppression circuit

The utility model discloses a direct -current input surge suppression circuit, including providing DC power supply's input and being used for connecting the output of back level circuit, connect in surge protection circuit between input and the output, still contains surge protection detection circuitry, through increasing surge protection detection circuitry to current surge protection circuit, follow the input sample voltage signal of the switch element in the surge protection circuit promptly and give surge protection detection circuitry, this voltage signal's height represents that two kinds of different states of relay are actuation or off -state promptly in the surge protection circuit, it outwards exports the CS height to correspond after surge protection detection circuitry carries out level conversion, low level signal, from then the level circuit just can be high according to CS's signal level, low change, whether judge for effective actuation relay in preventing the surge protection circuit, and ca