Advance Transformer Company

Albert E Feinberg

Robert W Wisbey

Kenneth Woo

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.

Rapid start fluorescent lamp circuits with disconnect sockets

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.

Socket for fluorescent lamps

Microwave oven with a self-regulating circuit operated from a low voltage a.c. source based upon a substantially constant current transformer and condenser series combination and having a return path for current on alternate half cycles. For defrosting food the magnetron is operated at partial power which is achieved by decreasing the voltage applied to the magnetron. This is done either by increasing the capacitive reactance in series with the secondary of the transformer or by decreasing the secondary voltage. Switching problems are solved by providing the arrangement of the invention at the grounded end of the transformer secondary. The self-regulating circuit is required to be of the type which has one end of the secondary winding grounded.

Magnetron energizing circuit

A magnetron energizing circuit preferably uses two transformers of the high leakage reactance type having isolated secondaries with an end terminal of each secondary connected to a common point which is at ground potential. The secondaries are connected to series condensers in two loops which provide leading current flowing in the secondaries at all times while both are connected in the circuit to produce saturation in the respective cores of the secondaries whereby to achieve substantially constant current and good regulation for variations in the primary voltage. A single magnetron is served by the circuit and variations in the loading of the magnetron are also compensated for by virtue of the substantially constant current circuit. The secondaries are connected in opposite phase with respect to the respective capacitors which they serve to charge to obtain a full wave doubler operation when the transformers are both in circuit but with low peak current. The combined secondaries and condensers are connected through a rectifier or rectifiers to a magnetron used for heating purposes, the magnetron participating in the overall operation of the circuit and being of the continuous wave pulsed type so as to achieve heating in cooking ovens or the like. Disconnecting one of the transformers from the circuit converts the circuit into a low power, but efficient half wave voltage doubler circuit. Isolating rectifiers prevent circulating currents. A modified form uses a single transformer having two isolated secondaries.

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Chicago, IL, United States of America

Albert E Feinberg