Patent ID: 8902550

Claim:
A direct-current switch, comprising: an electronic open/close switch inserted in a direct-current path along which a direct current flows in order to make the direct-current path an open circuit or a closed circuit; a parallel mechanical open/close switch connected in parallel to the electronic open/close switch; a serial mechanical open/close switch connected in series to the electronic open/close switch; a switch control circuit that controls the opening or closing time difference mutually among the parallel mechanical open/close switch, the electronic open/close switch, and the serial mechanical open/close switch; and a regenerative diode connected in parallel to the serial mechanical open/close switch so as to be reverse-biased, wherein when making the direct-current path a closed circuit, the switch control circuit: makes the serial mechanical open/close switch a closed circuit, makes the electronic open/close switch a closed circuit after a predetermined time longer than a time needed for chattering of the serial mechanical open/close switch to abate, maintains the serial mechanical open/close switch closed during all a time in which the electronic open/close switch is closed, makes the parallel mechanical open/close switch a closed circuit after the electronic open/close switch has been made a closed circuit, and maintains the electronic open/close switch closed during all a time in which the parallel mechanical open/close switch is closed, and when making the direct-current path an open circuit, the switch control circuit: makes the parallel mechanical open/close switch an open circuit, makes the electronic open/close switch an open circuit within a time longer than a time needed for chattering of the parallel mechanical open/close switch to abate, and within a time shorter than a time taken for the temperature of the electronic open/close switch to rise to a predetermined temperature, and makes the serial mechanical open/close switch an open circuit after the electronic open/close switch has been made an open circuit.