Drive device for single-phase series commutator motor

A drive device for a single-phase series commutator motor including a field winding and an armature, the drive device comprising:

• a pair of drive switches, each of which is provided at either end of the field winding in the motor, the pair of drive switches being adapted to be able to switch between a drive position, which is a position that connects the field winding and the armature of the motor serially to an external power source to drive the motor, and a brake position, which is a position that brakes the motor by connecting the field winding to the armature in a direction opposite to that at the time the motor is being driven;
• a first diode, a switching element, and a current detection unit that are arranged, in this order from one end of the armature, on a braking current path that is formed of the armature and the field winding when the pair of drive switches is in the brake position, the first diode being adapted to allow a braking current to flow through the braking current path in one direction, the switching element being adapted to electrically conduct/interrupt the braking current path, and the current detection unit being adapted to detect the braking current flowing through the braking current path;
• a capacitor for charge accumulation disposed between a first partial path between the first diode and the switching element on the braking current path and an other end of the armature;
• a second diode adapted to keep allowing the braking current to flow through the field winding when the switching element is in an off-state by directly connecting a second partial path between the switching element and the current detection unit on the braking current path and the other end of the armature;
• and
• a current control unit adapted to switch the switching element between on and off states so that the braking current detected by the current detection unit becomes a predetermined amount when the pair of drive switches is in the brake position.