Power reducer for fluorescent lamps

In combination, a rapid start fluorescent lighting fixture having at least one fluorescent lamp tube with starter filaments at opposite ends thereof, and an electric circuit therefor comprising

• a rapid start ballast comprising:
• an autotransformer having a primary winding, a secondary winding connected to opposite ends of said lighting tube for maintaining an illuminating flow therethrough once started, and a plurality of step-down filament windings,
• a first capacitor in circuit between the high voltage output side of said autotransformer and said step down transformer secondary windings,
• a resistor connected in parallel with said capacitor,
• power saving means comprising an isolation transformer having a primary connected to the secondary of said step down transformer and a secondary connected to one of said fluorescent lamp filaments,
• a second capacitor connected between the primary and secondary of said isolation transformer,
• a resistor connected in parallel with said second capacitor,
• an inductor connected in series with said primary winding of said autotransformer, and
• a thermally actuated overload switch connected in series with said inductor and operable to open in response to an excessive flow of current resulting from failure of said ballast capacitor or any thermal overload conditions.

A method of reducing power consumption in a rapid start lighting fixture having a rapid start ballast and a conventional rapid start fluorescent lamp tube, where said ballast includes an autotransformer having a primary winding, a secondary winding and a plurality of step-down filament windings, and a capacitor in circuit with the high voltage output side of the autotransformer,

• said method comprising
• providing an isolation transformer,
• connecting the primary of said isolation transformer to one of said step-down filament windings and connecting the secondary of said isolation transformer to one of the fluorescent lamp filaments,
• providing a capacitor and connecting same between the primary and secondary of said isolation transformer,
• providing a resistor connecting same in parallel with said last named capacitor,
• providing an inductor and connecting same in series circuit with said autotransformer,
• providing a thermally actuated overload switch and connecting the same in series with said inductor operable to open in response to an excessive flow of current resulting from failure of said ballast capacitor or any thermal overload conditions, and
• said ballast and associated circuit, and said isolation transformer, the capacitor and resistor connected thereto, and said inductor cooperating to produce a relatively square wave output to said fluorescent lamp tube.