| 摘要 |
A water level monitoring and alarm circuit for the bilges of boats has two sets of probes (14, 15), (15, 16) which are contacted when the water bilges reach critical levels (A, B). The current flow through the probes (14, 15) switches on a timer (IC1) to operate a bilge pump (12) for a preset period to lower the water level. A by-pass circuit (Q2) retriggers the timer to continue operation of the pump (12) if the water has not fallen below level A. If the water level rises to level B, current flow through probes (15, 16) trip a timer (IC2) to operate an audible piezo alarm (PA) and visual alarm (LED1). |
