| 摘要 |
PROBLEM TO BE SOLVED: To sufficiently prevent the occurrence of hunting operation without using an electronic control circuit, etc.SOLUTION: A drain pump device includes a pump (2) for discharging drain water stored in a drain tank (12), a first switch (3) to be turned on when the water level of the drain water exceeds a lower limit water level and to be turned off when it is not higher than the lower limit water level, a second switch (4) to be turned on when the water level of the drain water exceeds an upper limit water level and to be turned off when it is not higher than the upper limit water level, and a relay (6) state-changeable between an on-state to energize the pump and an off-state to stop the energization. The relay becomes the on-state in the state that the first switch and the second switch are both on, keeps up the on-state in the state that the second switch is only turned off after that, and becomes the off-state in the state that the first switch is also turned off further after that.SELECTED DRAWING: Figure 1 |
