Abstract: An automatic switching apparatus is disclosed for a system employing a battery and a charging device. A load is automatically disconnected in response to the decrease in voltage caused by an inactivation of the charging device so that the battery will not be undesirably discharges if the load is not turned off. An override switch is provided to allow the load to draw power even when the charging device is not operating.

Abstract: A DC voltage source of amplitude below the DC voltage requirement of a load to be energized drives a pair of complementary transistors which are alternately turned on and off to apply supply voltage alternately to each of two capacitors connected in series. The sum voltage of the two capacitors is applied, in one embodiment, directly to a voltage regulator and filtered and, in another embodiment, is added to the DC source voltage prior to being regulated and filtered. The converter output is capacitively coupled to the DC supply voltage, thus furnishing a common AC connection.