Dual-protection circuit for mine intrinsically safe power supply

The invention discloses a dual-protection circuit for a mine intrinsically safe power supply. The dual-protection circuit for the mine intrinsically safe power supply comprises a first-level protection circuit and a second-level protection circuit. The input end of the first-level protection circuit is connected to the output ends of sampling circuits and the output end of the first-level protection circuit is connected to a first switch. The positive electrode of an input power supply and the positive electrode of the intrinsically safe output are connected through the first switch. The input end of the second-level protection circuit is connected to the output ends of the sampling circuits and the output end of the second-level protection circuit is connected to a second switch. The negative electrode of the intrinsically safe output and the negative electrode of the input power supply are connected through the second switch. The sampling circuits comprise a current sampling circuit and a voltage sampling circuit. The dual-protection circuit for the mine intrinsically safe power supply can cut off output in the case of overcurrent or overvoltage and is simple in structure, low in cost and capable of reaching the turn-off speed up to 1 us and automatically returning to work after the fault is removed.