| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce a circuit size and costs as compared with a prior art, and to prevent generation of overvoltage. <P>SOLUTION: A motor drive includes a Zener diode for gate overvoltage protection, and a second resistor. In the Zener diode for overvoltage protection, a cathode is connected to the other end of a first resistor with its one end connected to the connection end between a power supply and a motor, an anode is connected to a gate terminal, and a Zener voltage is larger than a supply voltage of the power supply and is smaller than a withstand voltage of a transistor. In the second resistor, one end is connected to a voltage application section, the other end is connected to the anode of the Zener diode for gate overvoltage protection, and a resistance value for applying a voltage not less than a prescribed value to the gate terminal by a voltage generated owing to an inverse current inflow is set, when an inverse voltage becomes larger than the Zener voltage and the inverse current flows in the Zener diode for gate overvoltage protection. <P>COPYRIGHT: (C)2011,JPO&INPIT |
