| 摘要 |
PURPOSE:To obtain a power supply controller of a pump motor which does not repeat drive and stop even if the water level varies due to the backflow of water in the pipes, by stopping power supply to the pump motor regardless of the water level after the water level in the water tank has lowered to the level at which the pump can not suck the water. CONSTITUTION:Since current is conducted to an electromagnetic coil of an electromagnetic relay X2 when a float switch 36d is closed, a b-contact X21 is opened to open the power supply circuit of an electromagnetic relay X1. But the electromagnetic relay X1 holds a current-conducting state against the self electromagnetic coil by closing an a-contact X12 parallelly connected with the b-contact X21, when the current is previously conducted. Therefore, even if the electromagnetic relay X2 opens the b-contact X21 interposed in the power supply circuit of the electromagnetic relay X1, the current condition of the relay X1 is not changed and hence, the b-contact X11 of the relay X1 interposed in the current feed line of the pump motor 35b is kept open. Accordingly, current is not conducted to the pump motor 35b and hence, the motor cannot be driven or stopped repeatedly. |
