| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a motor drive device which can surely protect a switching element, even if a non-insulated power supply with a simple structure is used as a power source to supply DC power to the switching element. <P>SOLUTION: A motor drive device 22 which generates a current signal by switching on and off switching elements 5a and 5b corresponding to a pulse width modulation signal and outputs the current signal to a drive objective motor 23 comprises: a non-insulated power supply 33 which has a rectification diode 3a and an output capacitor 3c, converts AC power to DC power, and supplies the DC power to the switching elements 5a and 5b; an electromagnetic relay including a make contact 2a which intermittently connects the supply route of the AC power to the non-insulated power supply; and discharge means 34 and 2b which discharge the electric charge of the output capacitor 3c when the make contact is switched to an open state to break the supply route. <P>COPYRIGHT: (C)2003,JPO |
