Isolation mechanism for facsimile copier - has make-before-break circuit on printed circuit board operated by metallic strip and plunger attached to lid

摘要

The printed circuit card (3) is held on a chassis (18), and is connected to the telephone line (4) by a plug (5). The wires of the latter are soldered to the tracks (6,7) on the PCB. The tracks have a break in the input (8,9;10,11) with a contact plane. The PCB is connected to the circuit functions of the facsimile (2). The lid (16) of the facsimile has a plunger mechanism attached at one end, and comprising a rod (14) with springs (15) and having a metallic strip contact (12,13). The contact maintains the telephone circuit with a 48 volt supply when the lid is down, and releases the contact when the lid is up. ADVANTAGE - Reduced mfg. costs whilst maintaining isolation of components when hood is open.