Device is hauled oneself willingly into fully to low pressure

The utility model provides a device is hauled oneself willingly into fully to low pressure, including the voltage acquisition circuit who connects gradually, control circuit and switch circuit, switch circuit includes a control switch, the 2nd control switch and the 3rd control switch, voltage acquisition circuit gathers the voltage of outside first power inlet wire and outside second source inlet wire, and the data transmission that will gather to control circuit, when having normal just another the power inlet wire decompression of a certain power inlet wire voltage in first power inlet wire in outside and outside second source inlet wire, the closure control switch in the normal power inlet wire of voltage that establishes ties, break off the control switch who establishes ties in the power inlet wire of decompression, and three closed control switch, the function is hauled oneself willingly into in the realization, when the first power inlet wire in outside and outside second source inlet wire voltage all when normally predetermineeing the within range, a closed control switch and the 2nd control switch, and break off the 3rd control switch, automatic recovery normal operating mode's function realizes not having a power failure.