Abstract: The present High Intensity Discharge electronic lamp ballast uses a “set of controls” that can be performed by controlling energy delivery by the “line side converter” to the “lamp side inverter”. This set of controls comprises: 1) open circuit voltage control, 2) breakdown voltage amplitude control, 3) glow-to-arc transition current control, 4) “initial arc development” current control, 5) “arc stabilization” current control, 6) lamp power control, 7) lamp dimming, 8) “lamp rectification” current control, and 9) short circuit and lamp fault protections. One of the primary advantages of this “line side converter” energy delivery control method is that it doesn't need to vary the lamp operating frequency to achieve the above-noted controls.

Abstract: The improved single stage power converter circuit topology substantially reduces EMI that is conducted to the AC line, reduces input AC current inrush, improves output ripples by the use of an auxiliary supply near zero crossings of the line AC voltage, provides Power Factors greater than 0.95, provides Total Harmonic Distortions less than 15%, and maintains constant power, including constant power in a non-linear output load. Further, this circuit topology provides output open and short circuit protections by reducing current stress in power components. This topology can also make the power source to appear as a fast-acting variable impedance source, an ideal source for powering an output load that has negative resistance characteristics such as gas discharge lamps.

Abstract: The present High Intensity Discharge electronic lamp ballast uses a “set of controls” that can be performed by controlling energy delivery by the “line side converter” to the “lamp side inverter”. This set of controls comprises: 1) open circuit voltage control, 2) breakdown voltage amplitude control, 3) glow-to-arc transition current control, 4) “initial arc development” current control, 5) “arc stabilization” current control, 6) lamp power control, 7) lamp dimming, 8) “lamp rectification” current control, and 9) short circuit and lamp fault protections. One of the primary advantages of this “line side converter” energy delivery control method is that it doesn't need to vary the lamp operating frequency to achieve the above-noted controls.

Abstract: The present switch mode power converter having multiple inductor windings equipped with snubber circuits uses a small value inductor that has at least one properly oriented secondary winding, and ultra fast diodes interconnect the primary and the secondary windings of this inductor for providing protection against momentary short circuits, reductions of dv/dt, and switching losses.

Abstract: The enclosed electronic ballast housing provides improved convection heat transfer for lowering the ambient housing temperature for keeping the junction temperature of power semiconductors inside the enclosed electronic ballast housing within certain specified temperature ranges for long-term reliable operation. The enclosed electronic ballast housing includes at least one folded fin on at least one of the enclosed electronic ballast housing surfaces, the folded fin may be manufactured from the same piece of material as the ballast housing for improved heat transfer. The folded fins are substantially parallel to their respective adjacent surfaces. Additionally, the enclosed electronic ballast housing includes separating portions of heat dissipating sections of ballast circuitry outside of the housing ballast.

Abstract: The present switch mode power converter having multiple inductor windings equipped with snubber circuits uses a small value inductor that has at least one properly oriented secondary winding, and ultra fast diodes interconnect the primary and the secondary windings of this inductor for providing protection against momentary short circuits, reductions of dv/dt, and switching losses.

Abstract: The control circuit for maintaining constant power in power factor corrected electronic ballasts and power supplies maintains constant power in a variable load. This constant power control circuit provides a closed loop constant power management process for gas discharge lamps by adding a scaled lamp voltage to a scaled voltage that is equivalent to the measured lamp current. This sum is then fed to a comparator for comparison with a fixed reference voltage. If there is a difference between the sum and the reference voltage, the comparator sends this information to an error amplifier of the gas discharger lamp power control circuit for corrective measures and closed loop control of gas discharge lamp power. Since the sum always must attain the same value as determined by reference voltage, when the lamp voltage increases from its nominal or initial value, the lamp current is decreased by a corresponding ratio to maintain a constant power in the gas discharge lamp.

Abstract: The control circuit provides an improved method for power factor correction characteristics and low Electro Magnetic noise. This control circuit uses an Electro Magnetic Interference abatement circuit that consists of a series connected diode in one of the DC input lines from the full wave rectifier and a capacitor connected across the DC input lines from the full wave rectifier to eliminate the Electro Magnetic Interference generated by the active power factor corrections and resonant circuit operations. This is accomplished in part by the operation of the series connected diode which blocks reverse currents, thereby preventing high frequency current present in the gas discharge control circuit from flowing back to the AC input line through the full wave rectifier. In addition, the use of the capacitor across the DC input line helps to absorb high frequency current that is present on the input lines from the full wave rectifier.

Abstract: The invention relates to an inverter powering a lamp that uses a switch to vary the resonance of the resonance circuit for starting and for operating.

Abstract: A circuit and method for controlling a power supply are disclosed, with specific application to dimming of a resonant inverter solid-state fluorescent lamp ballast. The control circuit produces a pulse train signal with pulses of variable duty cycle. The signal is integrated to provide a DC signal which the solid-state ballast uses to control the level of dimming of the lamp. When the duty cycle of the pulses is increased, the level of the DC signal increases, so that the ballast dims the lamp. Conversely, reduction of the pulse duty cycle increases the brightness of the lamp. The control circuit incorporates delay circuitry which suppresses the pulse output at powerup, so that the lamp starts at full intensity. Thereafter, the delay circuitry adjusts the pulse signal so that the lamp intensity is adjusted smoothly to the desired level.

Abstract: Circuitry for limiting a high frequency current through a load including a DC voltage source connected to a circuit ground; an inverter for converting the DC voltage to the high frequency current, the inverter being connected to circuit ground; a chassis containing the voltage source and the inverter where the chassis is connected to earth ground and where earth ground and circuit ground are at different electric potentials; sensing circuitry connected between earth ground and one of the output terminals of the voltage source to establish a current path from earth ground to the one output terminal of the voltage source to thus monitor any high frequency current which may flow through a person, for example, connected between one of the output terminals of the inverter and earth ground; and limiting circuitry for limiting the high frequency current through the person in response to the current through the person exceeding a predetermined limit.

Abstract: In a method or combination, a DC voltage supply, a converter including a series or a parallel resonant circuit for converting the DC voltage to a sinusoidal current, and a load including at least one fluorescent lamp responsive to the sinusoidal current to effect excitation of the lamp.

Abstract: A device and method for sputtering dielectric targets, for reactive sputtering, and for sputter etching, including a target, anode and auxiliary electrode where each of the foregoing elements is electrically isolated from a grounded chamber containing a plasma and during a sputtering cycle, the anode and target are connected across a first floating power supply which applies a first series of waveforms to the target to render the target positive with respect to the plasma and thus sputter it and during a charge removal cycle, the auxiliary electrode and target are connected across a second floating power supply which applies to the target a second series of waveforms during respective intervals between the first series of waveforms to render the target negative with respect to the plasma and thus remove any positive charge build up which may have occurred during the sputtering cycle.