D75 is a standard Grade 2 surface contact. 6 wire clamping screw down terminals are provided on the PCB – two for the switch, two for tamper and two unlinked spares. The tamper on this contact is provided by a sprung microswitch, which will detect removal of the lid. This contact is Normally Open (N/O) - The circuit through the contact is complete until the magnet is moved close by. With the magnet in close proximity, the circuit through the contact is broken.
