Abstract: A method of supplying electrical power to a load is provided. The method includes the step of providing a removable plug-in cartridge having markings related to a desired value of an electrical output of a power supply unit. The method further includes configuring the power supply unit to receive the removable plug-in cartridge such that the removable plug-in cartridge operates to set an output value of the power supply to the desired value.

Abstract: A method of supplying electrical power to a load is provided. The method includes the step of providing a removable plug-in cartridge having markings related to a desired value of an electrical output of a power supply unit. The method further includes configuring the power supply unit to receive the removable plug-in cartridge such that the removable plug-in cartridge operates to set an output value of the power supply to the desired value.

Abstract: A power supply for supplying electrical power at a predetermined level is provided. The power supply includes circuitry configured to receive an electrical input and produce an electrical output. The power supply further includes a housing with an opening configured to receive a removable plug-in cartridge. The removable plug-in cartridge is configured to limit the electrical power output to the predetermined level.

Abstract: Ballasts with crest factor control are provided. During a transition to a given half cycle steady state, the current provided to reach the steady state is varied, such as turned off for a short period. This reduction during the transition may reduce or eliminate overshoot. The crest factor control is active, such as altering the timing or number of on/off/on switchings used to control crest factor. The active control may be based on any information, such as time, lamp voltage feedback, or other lamp dependent feedback.

Abstract: A system for controlling lamp striking voltage and recovery of energy from resonant lamp strike circuits used for electronic high intensity discharge lamp ballasting and other lamp ballasts is provided.

Abstract: A low current loss ballast operates a high intensity discharge lamp with or without radioactive krypton. A by-pass capacitor in conjunction with a resonant strike circuit limits high frequency ripple applied to a lamp during continuing operation. Different resistor combinations are connected to drive dual buck converters of the ballast. One combination is used for high frequency operation for striking. Another combination is used during low frequency operation to limit current loss. In a strike mode of operation, combinations of signals at a resonant frequency for striking and subharmonic frequencies are applied to a resonant circuit. The signals at the subharmonic have less than a 50% duty cycle.

Abstract: Ballasts with crest factor control are provided. During a transition to a given half cycle steady state, the current provided to reach the steady state is varied, such as turned off for a short period. This reduction during the transition may reduce or eliminate overshoot. The crest factor control is active, such as altering the timing or number of on/off/on switchings used to control crest factor. The active control may be based on any information, such as time, lamp voltage feedback, or other lamp dependent feedback.

Abstract: Auxiliary power is provided on a lighting ballast by a charge pump circuit. A direct current power supply circuit in the ballast outputs auxiliary power for operation of loads other than the lighting load of the ballast.

Abstract: A low current loss ballast operates a high intensity discharge lamp with or without radioactive krypton. A by-pass capacitor in conjunction with a resonant strike circuit limits high frequency ripple applied to a lamp during continuing operation. Different resistor combinations are connected to drive dual buck converters of the ballast. One combination is used for high frequency operation for striking. Another combination is used during low frequency operation to limit current loss. In a strike mode of operation, combinations of signals at a resonant frequency for striking and subharmonic frequencies are applied to a resonant circuit. The signals at the subharmonic have less than a 50% duty cycle.

Abstract: A means of effecting color change or improved color rendition by altering the ratios of average lamp arc current to RMS lamp arc current in a high intensity discharge lamp typically a metal halide lamp operating at less than nominal lower rating.

Abstract: A means of effecting colour change or improved colour rendition by altering the ratios of average lamp arc current to RMS lamp arc current in a high intensity discharge lamp typically a metal halide lamp operating at less than nominal power rating.

Abstract: A circuit for ballasting for high intensity discharge (HID) lamps, wherein the necessary lamp striking voltage, warm-up current and steady state running current may all be controlled using only two power switching transistors operating in two discrete modes is provided for avoiding acoustic arc resonance during the steady state running. A low frequency lamp current is generated with a frequency modulated high frequency ripple.

Abstract: A means of ballasting for high intensity discharge (HID) lamps, wherein the necessary lamp striking voltage, warm-up current and steady state running current may all be controlled using only two power switching transistors 9,10 operating in two discrete modes is provided for avoiding acoustic arc resonance during the steady state running. A low frequency lamp current is generated with a frequency modulated high frequency ripple.

Abstract: The invention provides a bi-directional voltage regulator having a controller, an input circuit and an output circuit, the input and output circuits being capacitively coupled one to the other and being symmetrical one relative to the other, wherein each circuit comprises two terminals (AC1, AC2; AC3, AC4) across which are connected a capacitor (C2a; C2b) and, in parallel with the capacitor (C2a; C2b), a series connection of an inductor (L1; L2) and a switching network (S1; S2) controlled by the controller. Each switching network (S1; S2) has two branches in anti-parallel, of which each branch permits only uni-directional current flow and at least one branch comprises a switching means. If one branch only of each switching network comprises a switching means then the regulator of the invention is a DC regulator which has the advantage over conventional Ćuk converters in that it permits bi-directional power flow.

Abstract: A means of ballasting for high intensity discharge (HID) lamps, wherein the necessary lamp striking voltage, warm-up current and steady state running current may all be controlled using only two power switching transistors 9,10 operating in two discrete modes. A further feature provides a means of lamp power control over a range of lamp voltages such that the lamp power input remains substantially constant throughout the ageing of the lamp 19. The use of this means of ballasting HID lamps can offer major cost benefits, lower circuit complexity, longer lamp life and colour maintenance and increased flexibility of the wiring installation and lamp position relative to the ballasting and striking means.

Abstract: In a voltage regulator converter circuit comprising an input 20 and an output 25, an input signal can be controlled by applying a high frequency switching signal (1 KHz-30 MHz) to an input circuit 12, 13, 16 and 17. An output of the circuit is obtained via an inductor 28 and a capacitor 29. The input can be DC to 500 Hz and the output can be DC or AC. Switches 12, 13, 16 and 17 can be thyristors, bipolar transistors, field effect transistors or IGBi transistors. Diodes 11, 14, 15 and 18 are connected in series with the switches 12, 13, 16 and 17. In an alternative embodiment (FIG. 9) the four switches can be connected in series between an AC input and an output is obtained from a center point of the series connection via an inductor (106) and a capacitor (107). A further aspect (FIG. 10) relates to transformed coupled input and output switching stages.