Abstract: A power source for operating gas discharge lamps and other loads at high frequency, typically utilizing a dc source or a rectified ac source to produce a high frequency output. An inverter with oscillator circuit and first transformer has the secondary or load winding connected to a second transformer which provides a feedback signal to the transistor of the oscillator circuit through another transistor which functions as a variable resistance in the base drive of the oscillator transistor for maintaining power to the load substantially constant. A third winding on the inverter transformer is used to provide a control signal to the base circuit of the variable resistance for protecting the circuit components during an open secondary or no load condition.

Abstract: A power source for operating gas discharge lamps and other loads at high frequency, typically utilizing a 120 volt ac source rectified to provide a 150 volt dc input and providing a 20,000 hertz output. An inverter with current feedback in place of the conventional voltage feedback providing voltage turn off and voltage turn on in less time and providing increased base current during the conduction time for reducing the voltage-current product and heat generated in the inverter. Voltage limiting and current limiting features are provided for the basic circuit. Inverter circuits with two transistors for increased loads are also provided.

Abstract: A power source for operating gas discharge lamps and other loads at high frequency, typically utilizing a 115 volt ac source rectified to provide a dc input in the order of 150 volts, and providing a 20,000 hertz output. An inverter with power supply, oscillator circuit and transformer, with conventional primary, secondary and feedback windings for operating the transistor oscillator. An additional output winding on the transformer with a rectifier and filter providing a supplemental dc supply connected to the main dc supply in parallel or in series to supplement a fluctuating main dc supply and maintain continuous oscillator operation while utilizing small filter capacitance and substantially reducing peak ac line current.

Abstract: A power source for operating gas discharge lamps and other loads at high frequency, typically utilizing a 115 volt ac source rectified to provide a 150 volt dc input and providing a 20,000 hertz output. An inverter with a transistor current control for protection against transistor damage under open circuit, starting and no-load conditions, with low power consumption under no-load and with dimming capability. An inverter with a detector circuit connected across the feedback winding or an additional control winding for developing a control signal varying as a function of the feedback winding output, and a zener diode or other device for connecting the control signal to the base of the transistor in current controlling relation when the control signal exceeds a predetermined value.