Abstract: A two-lead starter circuit for a gaseous discharge lamp is composed of only four components, namely a capacitor, a bilateral voltage-sensitive switch, a pulse transformer and a resistor. These components are connected in a series-parallel circuit arrangement which is both more economical and more reliable than prior-art two-lead starter circuits.

Abstract: A hybrid ballast apparatus for starting and operating a plurality of series-connected discharge lamps and which provides protection against electric shock. The ballast apparatus includes first and second bidirectional thyristors connected in parallel with first and second ones of said lamps, respectively, and a trigger control circuit for simultaneously triggering the thyristors into conduction. Each lamp has two filaments and means are provided for connecting an L-C ballast device, the lamp filaments and the first and second thyristors in a series circuit across the AC supply voltage terminals. If one end of a lamp is removed from its socket, the series circuit is opened so that the maximum voltage at any lamp electrodes is limited to the AC supply voltage.

Abstract: A ballast circuit for starting and operating a preheat type circular fluorescent lamp, which replaces a multiple wattage incandescent lamp in a three-way incandescent lamp socket, so that the fluorescent lamp can be ignited to function at three different operating wattages. A lamination stacked core structure mounts first and second coils. A passive circuit element, such as positive temperature coefficient resistor also known as a thermistor, is connected in the circuit, which includes a three-way incandescent lamp screw base, for current switching functions to achieve the desired ignition and operating currents for the fluorescent lamp at its different operating wattages.

Abstract: A two-lamp rapid start fluorescent lamp circuit in which the lamps are ignited in sequence and then operated in series. The circuit being energized from a low voltage a.c. source through the use of a substantially conventional ballast which utilizes a transformer having a primary winding and a secondary winding connected in autotransformer relationship. The circuit includes a disconnect socket and a conventional two contact socket for mounting each lamp. The disconnect sockets in one circuit are arranged in one example to open the connections between the filament windings and a filament of each lamp. In another circuit one disconnect socket is arranged to open a connection to a filament winding and the other disconnect socket is arranged to open one of the connections to the line.

Abstract: Sockets for fluorescent lamps of the type which have a pair of parallel bayonet pins in each end thereof, the lamp adapted to be moved at right angle to the axis of the lamp in order cause the pins at opposite ends to enter grooves or channels formed in the socket. Rotation of the lamp rotates the four pins to detent positions where electrical conductive engagement is made with electrical contacts provided in the socket by means of which circuits may be completed between the lamp filament ends and other electrical components. The sockets of the invention have channels formed therein which lead the lamps to rotate about 135.degree. before electrical conductive engagement can be made. Additionally the lamps must be rotated in a particular direction in order to effect the seating thereof and when so seated the lamps are substantially captured in dead end grooves providing a high measure of reliability and safety.

Abstract: 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.

Abstract: An auxiliary capacitor is added to a first capacitor formed from two metallized films wound into a cylindrical roll. Once the two metallized films have been wound a sufficient number of layers to form a capacitor having the desired capacitance, the auxiliary capacitor is added by one of two methods. In the first method, one of the metallized films is cut and a plain film is inserted between the roll and the uncut metallized film. After the plain film has been inserted and wound a portion of a turn, a metal foil is inserted between the plain film and the dielectric side of the uncut metallized film. The two films and foil then are wound together a sufficient number of layers to form the desired capacitance of the auxiliary capacitor.An electrical contact foil may be added between the plain film and the metal foil or the metal foil may be left slightly exposed for electrical contact to be made to it.In the second method both metallized films are first terminated. The core then may be sealed and heat treated.