| 摘要 |
PURPOSE:To automatically supply the fixed amount of water in a bathtub by a method wherein a flow sensor, which issues pulse signals in proportion to feed water flow rate when a solenoid valve in a feed water piping is open, is provided and the solenoid valve is closed by means of the flow sensor, when the integrated value of the outputted pulse signals is reached to a set value. CONSTITUTION:When a starting switch SS is turned on for use, a solenoid valve SV1 is open in order to feed water into the bathtub. At this time, pulses, the number of which is proportional to the flow rate of the water passing through the water piping, are issued from the flow sensor 4 and said pulse signals are sent through a wave-form shaping circuit 7 to an integrating circuit 8. The integrating circuit 8 has a capacitor C1, which continues to be charged during the time the pulse signals continue. When the terminal voltage of the capacitor C1 exceeds a reference voltage, the output of a comparator U2 is inverted from the high level to the low level. Consequently, a transistor Q3 is turned OFF, resulting in putting a relay 1K in inoperative and the solenoid valve SV1 is closed by means of the turning-OFF of a contact 1K1 in order to stop the water-feeding into the bathtub. |
