Abstract: A protection circuit for a battery charger for safely charging a battery from a remote electrical power supply is disclosed. The protection circuit includes a power control means responsive to input from the remote power supply; an overload sensing means responsive to the power control means and to the negative polarity of the battery; a main switching means responsive to the overload sensing means and to the power control means wherein the main switching means controllably limits current output in the presence of a slight overload condition, and deactuates the battery charger in the presence of a large overload condition.

Abstract: A high frequency battery charger operable from a 120 volt AC line power source which is rectified and converted by a blocking oscillator into 20-200 Khz rectified output for battery charging. A sensor for determining full battery charge serves as a power cut off to the battery with provision, if desired, for continued trickle charge of the battery.

Abstract: A high frequency power supply with inductive coupling and a SCR starter to light two fluorescent lamps is described. It supplies high frequency square waves to the fluorescent lamp for improved light output, efficiency and stability of operation. The rectified line voltage from a full wave rectifier is fed via a SCR starter to two transistors that form an inverter circuit. The inverter circuit is coupled to a ferrite core autotransformer. The secondary windings of the autotransformer are used to heat the filaments of the electrodes of the fluorescent lamp, and to form a reactive coupling along with inductors for stabilizing the arc discharge of the fluorescent lamp.