| 摘要 |
PURPOSE:To improve the reliability of a whole motor driver by providing a malfunction detector for detecting disconnection of an operation unit and a signal line in the motor driver. CONSTITUTION:The resistors R3-R5 of an operation unit are so connected in series as to repeat the contacts P0-P3 of a switch SW. A control voltage Vc is supplied from one end of the series connection to a differential amplifier DEF through a signal line W. Here, when the line W is disconnected, the voltage Vc is raised to a power source voltage Vc, a transistor Q1 is turned OFF, and a transistor Q2 is turned ON. Thus, a power source potential Ve is applied to the normal and reverse rotation terminals N, R of a motor driving circuit IC, and the circuit IC stops operating. |
