Standby power source for an ac alarm system

Claim 1

Apparatus for supplying AC power to an AC load comprising AC input means for receiving AC power from AC power mains, a battery, a battery charger having an input connected to said AC input means and an output, a battery having terminals, an inverter means for converting DC power to AC power and having an input for receiving DC power and an output for transmitting AC power, said inverter means including a solid state oscillator means which is energized to generate AC power upon the receipt of DC power, a first controlled switching means normally connecting saiD AC input means to the AC load, and when switched opening such connection a second controlled switching means normally connected the output of said battery charger to the terminals of said battery and when switched opening such connection, a third controlled switching means which is normally open and when switched connecting the terminals of said battery to the input of said inverter means for energizing said solid state oscillator means, fourth controlled switching means which is normally open and when switched connecting the output of said inverter means to the AC load, and control means connected to said AC input means and operative in the absence of AC power on the AC power mains for switching each of said switching means.