Abstract: An energy conversion device has a self-oscillating transistorized L-C series-resonant half-bridge inverter circuit having alternating resonant inductor current and adapted to deliver a high frequency signal to an effective load coupled effectively in parallel with the capacitor. The device includes a DC voltage supply able to provide DC voltage between the DC terminals; an artificial load arrangement connected to the DC terminals and operable to effectively couple itself in parallel with the capacitor; a load-coupling transformer; and a saturable feedback transformer operable to sense the alternating resonant inductor current and to control and adjust the frequency of the oscillation in proportion to the effective load applied effectively in parallel with the capacitor.

Abstract: An electronic ballast to power a gas discharge load (FL1) operating from a low frequency AC voltage source (ACVS) equipped with a dimmer (DIM) and having variable voltage magnitude. The device comprising a primary resonant oscillator (RO1) exhibiting an inductive character of frequency dependent impedance as an auxiliary resonant inductance (La) interacting with an auxiliary resonant capacitance (Ca) coupled to a rectifier circuit (RB, VSD) which performs switching and rectifying functions developed by and synchronized with a pulsating current drawn from the rectifier circuit by the primary oscillator circuit (RO1) equipped with switching transistors (Q1, Q2) and adapted to deliver to the gas discharge load (FL1) high frequency signal to of a variable magnitude proportional to the variable magnitude of the voltage of the AC voltage source.

Abstract: A power line-operated electronic converter is adapted to deliver a relatively constant magnitude high frequency signal to a load(112) and is operable to draw a substantially sinusoidal current from the AC voltage source (101). The converter has DC input terminals (B+,B-) having a capacitor (105) connected therebetween. First and second rectifier bridges (103,104) are coupled to the DC input terminals. A resonant oscillator circuit (108) is coupled to the DC input terminals and to the transistor inverter employing a resonant inductor (111) and a resonant capacitor (110). An input-output feedback is implemented by coupling of a voltage developed across the resonant inductor to a differential voltage proportional to a difference of a voltage developed across DC input terminals and a voltage provided by a rectified AC voltage source, and modulation of frequency of oscillation in proportion to the differential voltage.

Abstract: A power line-operated electronic converter is adapted to deliver a relatively constant magnitude high frequency signal to a load (113) and is operable to draw a substantially sinusoidal current from the AC voltage source (101). The converter has DC input terminals (V+, V-) having a capacitor (108) connected therebetween, rectifying bridge (103) and boosting rectifiers (D5,D6) coupled to the DC input terminals, a resonant oscillator circuit coupled to the DC input terminals and to the transistor inverter (106) employing two integrated and synchronized resonant circuits having two resonant capacitors (114,112) and one common resonant inductor (110) wherein one circuit is used to operate the load and the other to provide boosted pulsating DC voltage to be naturally added and integrated with the rectified voltage of the AC voltage source.

Abstract: A series-resonant ballast for powering at least one gas discharge lamp (16) having heatable filaments (12,15) includes: DC voltage input terminals (B+,B-); an oscillating resonant converter (55,26,51,52,53) for producing high frequency voltage for application to the gas discharge lamp; a control circuit (58) able to receive a control signal from the DC input terminals and from the resonant converter and operable to initiate and stop the oscillations; and direct current blocking circuits (57,50) coupled across the filaments (12,15) and operable to stop flow of the control signal from the DC input terminals, thereby the ballast will not oscillate and will not draw any power from the DC input terminals, whenever the gas discharge lamp is: (i) removed from the output terminals, (ii) is defective, or (iv) is inoperative.

Abstract: An electronic device for powering a gas discharge load (FL1) from a low frequency alternating voltage source (AVS). This device is drawing a current proportional to a voltage of the source (AVS) and is constituted by a resonant boosting circuit integrated into a power line voltage rectifier (BI,BRB) which performs boost switching and rectifying functions developed by and synchronized with a pulsating current drawn from the rectifier by a resonant oscillator circuit (RO1) equipped with a switching transistors (Q1,Q2) and adapted to energize the gas discharge load (FL1).

Abstract: A power line-operated electronic converter is adapted to deliver a relatively constant magnitude high frequency signal to a load (113) and is operable to draw a substantially sinusoidal current from the AC voltage source (101). The converter has DC input terminals (B+, B-) having a capacitor (111) connected therebetween, first and second rectifier bridges (137, 138) coupled to the DC input terminals, a transistor inverter (131) coupled to the DC input terminals, a resonant oscillator circuit (135) coupled to the DC input terminals and to the transistor inverter employing a resonant inductor (117) and a resonant capacitor (114), and an input-output feedback implemented by coupling and modulation of a voltage developed across the resonant inductor to a voltage proportional to a difference of a voltage developed across DC input terminals and a voltage provided by a rectified AV voltage source.

Abstract: A high efficiency, self-oscillating LC resonant multivibrator-inverter circuit employing a pair of switching transistor (Q1, Q2), two magnetically independent resonant inductors (L1, L2) and one common resonant capacitor (CR). Two secondary windings (NB2, NB1) of the resonant inductors provide feedback control for the switching transistors' bases, to provide intermittent feedback current to effect alternate and periodic conduction of the transistors. This results in the DC voltage rectified from the source S being converted to relatively high frequency AC voltage across output terminals (O1, O2). Such an arrangement enables construction of a cost effective, highly efficient, and highly reliable electronic ballast for fluorescent lamps.