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If the MCU unit is not used, connect CON2 to CON3 of the electromechanical switching unit. This unit works off a 5V, regulated DC power supply. Enclose both PCBs of the sensor module and the switching unit in a box.
This circuit is ideal for applications sensing closure of an assortment of different lids and/or caps. Next example could be to sense whether the gas-filling lid and the gas cap of an automobile are in place or not. Demand for such systems is increasing because gas-filling lids and gas caps can remain open due to carelessness of the vehicle operator or of a service attendant. Any potential arc or spark in and around the gas could ignite the fuel.
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