| 摘要 |
PROBLEM TO BE SOLVED: To prevent malfunction of a motor in water immersion by a simple configuration, and to enable a motor to be driven by switch operation in the water immersion.SOLUTION: A motor drive device 100 comprises a first relay 2a, a second relay 2b, a DOWN switch 4, an UP switch 5, transistors Q1 to Q3, a CPU 11, and a water immersion detection circuit 17. During water immersion, a water immersion detection signal is outputted from the water immersion detection circuit 17 and the transistors Q1, Q2 are turned on, and the relays 2a, 2b are both operated. Thus, contact points Y1, Y2 are switched to the side of a power source B and both ends of a motor 13 are brought to an equipotential, and accordingly the motor 13 does not rotate. When the DOWN switch 4 is operated in this state, the transistor Q3 is turned on and the transistor Q2 is forcibly turned off and accordingly the second relay 2b comes into non-operation. As a result, since the contact point Y2 returns to the side of a ground G, a current flows from the power source B to the motor 13, the motor is rotated in the reverse direction, and a window is opened. |
