Substitute power supply and battery charger for battery operated apparatus

A circuit element for use in battery operated apparatus, comprising,

• a. a conductive disc of a size enabling insertion within the battery compartment of said apparatus and having a formed terminal for coupling with a preselected terminal of the apparatus batteries,
• b. a circuit connector means for connecting said disc to a preselected terminal of an external direct current source, and
• c. an insulation pad of substantially the same size as said disc and selectively adhered to one surface of said disc for interrupting the coupling between said disc and said apparatus battery and to the other surface of said disc for interrupting the circuit between said disc and said apparatus.

A battery charging arrangement for battery operated apparatus, having normal operating batteries mounted in a compartment within the apparatus, comprising in combination,

• a. a pair of contact devices, sized for insertion within said compartment in tandem with the operating batteries, and fitted to contact different terminals of said batteries when inserted in said compartment,
• b. means for connecting said contact devices to opposite terminals of an external direct current source, and
• c. an insulation disc, of the same size as each contact device, selectively positioned on one of said devices for interrupting the energy supply circuit to said apparatus, whereby energy from said source is supplied to charge the operating batteries.