North American Philips Corporation

Advance Transformer Company

Joseph A Crawford

A rapid start fluorescent system which has its starting capacitance connected to a tap on the secondary of the ballast transformer which tap is located at a predetermined number of turns of the secondary.

Peak voltage reducer circuit for fluorescent lamps

A fluorescent lamp system including a relay whose coil is connected across the secondary of the transformer of the system and whose contacts interrupt the connection of the electrodes of the lamp system to their associated heater windings after lamp turn on.

Fluorescent lamp electrode disconnect method and arrangement for

Apparatus for sequentially igniting and serially operating a pair of electric discharge lamps from a source of AC supply voltage. The apparatus includes a transformer with a primary winding and first and second secondary windings mounted on a magnetic core having a slot under the second secondary winding. The first secondary winding has a high leakage reactance and the windings are serially connected with the secondary windings wound in opposition to one another. First and second capacitors are connected in series with the first and second lamps, respectively, to prevent the flow of DC current therethrough. By a novel choice of the ratios of the capacitance values of the second capacitor to the first capacitor and of the slot dimensions, superior operating characteristics for the apparatus are achieved.

Two capacitor apparatus for sequential starting and operation of

A ballast for a sequence start series operating circuit that includes two rapid start gaseous discharge lamps. The circuit includes a transformer with a primary winding and a loosely coupled secondary winding, a series first capacitor for providing a leading current when both lamps have been ignited and are operating and a second capacitor shunting the second-to-ignite lamp to by-pass that lamp during ignition of the first-to-ignite lamp and thereafter to develop a voltage across the second capacitor sufficient to ignite the second-to-ignite lamp when current flows in the by-pass branch. The lamps are of a variety which produces an undesirable current peak in the second-to-ignite lamp on each half cycle because the shunting second capacitor dumps its charge accumulated during each half cycle into the lamp. The secondary winding is made up of a main part and an auxiliary part, the auxiliary part being connected in series with the second capacitor in the by-pass branch so that an inductive reactance is added to the capacitance in that branch for suppressing the current peak in the second-to-ignite lamp on each half cycle. The auxiliary part of the secondary winding does not participate in the ignition of the first-to-ignite lamp but it does participate voltage-wise in the operation of both lamps in series.

Growing community of inventors

Chicago, IL, United States of America

Joseph A Crawford