Abstract: A power current regulator, in particular for airport lighting, includes transformers in series with intermediate taps on their secondary windings staged a various different numerical weights. In each case, one of said taps is selected by a latch memory (MV) preceded by an up/down counter (CD). These circuits are actuated by a control circuit as a function of the current detected by a current transformer (TIC) connected in series with the load.

Abstract: A power supply for a metal halide discharge lamp includes a circuit for applying a high voltage starting pulse to the arc tube of the lamp to initiate the discharge, a glow transition current to provide power transitioning the arc tube from its glow to its run mode, and a run power supply circuit to provide continuous controlled d-c current to the arc tube.

Abstract: A power supply is provided for an arc discharge lamp (38) which includes a relatively low voltage high current power supply section and a high voltage starter circuit (10). The low voltage section includes a transformer (15), rectifier (24), variable resistor (26) and a bank of capacitors (28), while the starter circuit (10) comprises a plurality of diodes (D1 to D12) and capacitors (C1 to C12) connected as a Cockcroft-Walton multiplier. The starting circuit is effectively bypassed when the lamp arc is established and serves to automatically provide a high starting voltage to re-strike the lamp arc if the arc is extinguished by a power interruption.

Abstract: A lighting system for a suspended ceiling comprises a central high-frequency power source feeding a plurality of power conditioning units permanently wired-in and mounted in various locations on the permanent ceiling above the suspended ceiling. Each such power conditioning unit provides a power-limited Class-3 high-frequency voltage at an output receptacle and is operable to power a special fluorescent lighting fixture by way of a light-weight flexible two-wire detachable connect cord. Special fluorescent lighting fixtures are mounted in the suspended ceiling, with each such lighting fixture being powered from a power conditioning unit mounted somewhere nearby on the permanent ceiling above.

Abstract: A current-balancing transformer is provided to supply plural parallel-connected electrical loads, especially loads such as gas discharge lamps which exhibit negative impedance and/or non-linear impedance over at least a part of their normal operating range. The current-balancing transformer forces current sharing among the loads so that each of the parallel-connected loads is supplied operating current.

Abstract: Two fluorescent lamps are lightened by a single inverter circuit which provides switched power current to a single leakage transformer. The leakage transformer has a single primary winding coupled with said inverter circuit and a pair of secondary windings each coupled with a related fluorescent lamp. The core of said leakage transformer has a closed magnetic core with a pair of short legs each of which bridges across said closed magnetic path with a non-magnetic material so that said pair of short legs provides three windows and bypass leakage magnetic paths. The first window is defined by said pair of short legs, and each of the second and the third legs is defined by one of said short legs and said closed magnetic path. The primary winding is mounted in said first window, and each of said pair of secondary windings is mounted in said second or third window.

Abstract: A voltage controller for use with a fluorescent-lighting system, the controller including a three-phase transformer having three auto-transformer windings each for developing two reduced voltages, three contactors for selectively coupling the full voltage and the reduced voltages to the lighting system, the contactors being switched in closed-transition fashion to avoid power interruptions, and another contactor for opening the winding-neutral connections during voltage switching to avoid shorting the transformer.

Abstract: A low-voltage system is disclosed for supplying operating power to high-voltage neon light tubes located within housings in the forms of letters and other shapes commonly used for illuminated advertising on the outside of buildings. Within the building, a first step-down transformer is connected to the conventional household power supply of 110 volt 60 Hz current. The step-down transformer produces a low-voltage signal in the range of 16 to 24 volts at the 60 Hz operating frequency. The low-voltage wires are passed through the exterior wall of the building on which the advertising sign housing is mounted and require no special precautions or high-voltage insulation due to the extremely low voltage involved. Within each high-voltage lamp housing, a solid state low-voltage to high-voltage conversion circuit is mounted. The input to this circuit comprises the 16 to 24 volt 60 Hz low-voltage current.

Abstract: An electronic ballast employs an electronic inverter which drives a main power transformer across the output of which terminations are connected for a plurality of fluorescent lamps. A high impedance capacitor is connected in parallel across at least one and less than all of the fluorescent lamps. An auxiliary transformer is interposed between the output of the main power transformer and the cathode elements of the fluorescent lamps. Upon start-up, the high impedance capacitor initially creates a bypass around lamps with which it is connected in parallel to thereby apply the entire high voltage output of the power transformer to start the remaining lamps. Once these lamps are started the voltage drop thereacross is reduced to allow the high voltage output to bypass the high impedance capacitor and start the lamps connected in parallel therewith. The auxiliary transformer provides good magnetic coupling and low voltage to the cathode elements of the fluorescent lamps.

Abstract: An electronic ballast circuit for powering a plurality of fluorescent lamps or the like from an unsmoothed DC voltage source includes a sine wave converter operatively connected to receive said DC voltage, for generating a high frequency alternating voltage of sufficient amplitude to power said lamps. The converter comprises a tank circuit and two push-pull transistors connected thereto and a current source capacitively coupled to said tank circuit for providing base drive alternately to each transistor. A lamp filament heater current cancellation circuit reduces power drain once the lamps have turned on.

Abstract: An improved electrical circuit for selectively controlling the power to a gaseous discharge lamp. One use for such circuit and lamp is in an ink-curing process for objects printed with multiple-colored ink wherein areas of the object are printed and cured in a multiple-step operation.

Abstract: An improved output configuration for a multiple-lamp electronic ballast system. The output includes a differential transformer having a primary adapted to be coupled in a first loop including a first filament filament drive winding and feedback winding and a secondary adapted to be coupled in a second loop that includes a second filament, filament drive winding and feedback winding.The improvement allows the entire ballast to be shut down when a lamp has been removed thereby avoiding aberrant oscillator operation under abnormal, yet predictable, lamp load conditions.

Abstract: A dimmer circuit for an inverter-driven electronic ballast system. The ballast includes an output transformer having a primary winding coupled to the inverter output and a secondary winding adapted to be coupled to a lamp filament winding for supplying power to the filament. An interstage transformer has a primary winding adapted to be coupled to a lamp filament and a secondary winding coupled to an inverter input for applying a feedback signal derived from the filament current at that input. The dimmer circuit is in the form of a feedback loop that includes a winding on the primary of the output transformer, a winding on the primary of the interstage transformer, and a variable impedance coupling those windings. Varying the impedance necessarily varies the total feedback loop impedance and therefore the amount of feedback applied at the inverter output and, inversely, the power supplied to the lamp filament.

Abstract: An improved drive scheme for a pair of push-pull inverter transistors in an electronic ballast circuit. The inverter output is coupled through a series resonant circuit comprising a capacitor and the primary winding of an output transformer. The resonant circuit is coupled to the inverter output through an additional winding on the primary of an interstage so that a component of the loop current is fed back to the bases of the push-pull transistors, thereby compensating for phase errors in the drive signal applied at the inverter input.

Abstract: A power supply for a high intensity discharge lamp is provided wherein the secondary windings of a pair of lamp strike pulse transformers are connected in series with the HID lamp directly across the AC supply, the impedance of these secondary windings acting as the only ballast elements of the power supply. The HID lamp is chosen to have relatively high operating and maximum starting currents so that warm-up time of the lamp is dramatically reduced while employing the lamp strike pulse transformers to perform the dual function of starting the lamp when either hot or cold and acting as the current limiting ballast for the lamp both during warm-up and under normal operating conditions.

Abstract: Starting and operating power is provided to a gas discharge lamp by a circuit which includes a constant-voltage current-limiting ferroresonant transformer connected to an AC source and having high and low voltage output terminals. A full-wave rectifying bridge is selectively connectable to either the high or low voltage output terminals by relay control means which includes a choke coil connected in series with the lamp and a magnet reed. On starting of the lamp the magnetic flux of the choke coil operates the reed for shifting to the low voltage condition, and on extinguishing of the lamp the collapse of the choke coil flux operates the reed for shifting to the normal high voltage condition. A transient high voltage starting pulse is applied to the lamp across a spark gap by a pulse generating starting circuit in which a capacitor, charged from the DC output, is discharged through a self-commutating SCR and an ignition transformer.

Abstract: A lamp ballast is disclosed which includes a main winding, and an auxiliary winding connected in series with the main winding. The auxiliary winding is wound concentrically with the main winding and with substantially fewer turns than it. The pitch (space between two adjacent turns) of the auxiliary winding is much higher than that of the main winding so that the turns of the auxiliary winding are spaced over the entire length of the main winding. When a voltage pulse of comparatively low amplitude is applied across the auxiliary winding by a conventional electronic lamp starter, a substantially higher amplitude pulse, which is sufficient to ignite a sodium lamp appears across the main winding, by reason of the improved transformer action between the two windings. Thereafter, the ballast provides sufficient support to the lamp to keep it on.

Abstract: 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.

Abstract: Method and apparatus for start and hot restart of a high pressure arc discharge lamp includes the application of an AC ionizing potential to the lamp, the ionizing potential characterized by a period such that the electron density of the fill material of the lamp is increased on each half cycle of said potential until the lamp is started. The invention is disclosed in an integrated ballast, and in an addition to an existing conventional ballast.This application is a continuation-in-part of Ser. No. 506,116, filed Sept. 16, 1974, and now abandoned.

Abstract: A high-voltage generator for an X-ray diagnostic apparatus which is initially intended for single-phase operation and subsequently, through an addition, completed in a simple manner into a three-phase generator.

Abstract: The body current of a TWT (traveling wave tube) is measured by generating a voltage that is proportional to the difference between the cathode and collector currents of the TWT without materially affecting either by passing the cathode and collector currents through separate transformer windings, wound in opposition, on both a linear core transformer and a nonlinear core transformer with separate windings coupling each transformer to the other. A voltage pulse is introduced into another winding on the nonlinear transformer causing a current flow in the circuit coupling the two transformers, the voltage magnitude of which is proportional to the difference between the cathode and collector currents which is the body current.