Patent ID: 8723562

Claim:
A drive unit for a reverse-conducting switching element which is a driven switching element, the reverse-conducting switching element being connected to an inductor and being configured by a voltage-controlled switching element and a free-wheel diode which are mounted on a single chip, the free-wheel diode being connected in anti-parallel to the voltage-controlled switching element, the drive unit comprising: a drive control means for turning on and off the driven switching element by performing a process to transfer electric charges to a conductive control terminal of the driven switching element on the basis of a turn-on command or a turn-off command; an active gate control means for changing a transfer rate of the electric charges in a period from when the transfer of the electric charges to the conductive control terminal is started until when it is completed; a judging means for judging whether or not forward current flows in the free-wheel diode; an inhibiting means for inhibiting the electric charges from being charged to the conduction control terminal which corresponds to the free-wheel diode in which the forward current is judged to flow, while the judging means judges that the forward current flows in the free-wheel diode; and a disabling means for disabling the active gate control means for changing the transfer rate of the electric charges, while the inhibiting means inhibits the electric charges from being charged to the conduction control terminal.