| 摘要 |
<p>Provided is a power supply device which enables a reduction in the energy loss caused by the forward voltage of a flywheel diode. In a load circuit in which a motor (M1) is driven by PWM controlling an electronic switch (T1) provided between a direct-current power supply (VB) and the motor (M1), a MOSFET (T2) is provided in parallel with the motor (M1). A parasitic diode (Dp) which the MOSFET (T2) comprises is provided in such a manner that the direction opposite to the direction of a load current (ID) is the forward direction thereof. By turning on the MOSFET (T2) in part of a period during which the electronic switch (T1) is off, a return current flowing through the motor (M1) is passed through the MOSFET (T2). Consequently, the energy loss can be markedly reduced as compared when the flywheel diode is used.</p> |
