Windscreen washer with fluid level warning - using level float and contact strips to operate warning when circuit broken

摘要

The fluid reservoir of the windscreen washer system has a float (21) moving along a vertical guide. Electric contact strips (20) on the guide are bridged by the float until a minimum level is reached. The circuit is broken and a warning circuit (22) operates the warning device (18). The device provides warning before the fluid is totally used and is especially useful for large fluid systems where headlamp washers are also fitted. A simple alternative uses a thermal switch, normally under the fluid level, heated by a coil in close proximity. As the coil and switch come out of the fluid the switch is heated and opens the circuit.