Abstract: A solar panel has n rows of solar cells in a regular grid array. The cells constituting each row are wired in parallel, the rows are wired in series and an equalizing network of n-1 capacitors are connected in electrical series. In a first configuration, a network of switches connects a first capacitor across the first row, and a second capacitor across the second row, and so on until the n-1th capacitor is connected across the cells of the n-1th row. In a second configuration, the switch network connects the first capacitor across the second row, and the second capacitor across the third row, and so on until the n-1th capacitor is connected across the nth row. This causes the voltage across each row to be substantially equal to the voltage across every other row. Since equal voltage is a hallmark of parallel connection, this voltage equalized series connection is referred to as a virtual parallel connection.

Abstract: High voltage switches are configured with a junction transistor driven with a transformer coupled AC drive signal in the common base configuration or driven by a capacitor coupled charge pump. The high voltage switches may be configured as half wave or full wave switches wherein the junction transistor is driven during one or both half cycles of the AC drive signal. Bipolar switches that can stand off high DC voltage of either polarity, or that can stand off high AC voltage, are configured from two junction transistors with their bases connected and their emitters connected. These switches may also be driven in full wave or half wave mode, by a transformer or by single or dual capacitive charge pumps. Either NPN or PNP transistors may be used. Example drive circuits, which can be constructed as low voltage integrated circuits, are given for all of the switch types.

Abstract: A preferred solar panel of rectilinear geometry has n row of m solar cells each row in a regular grid array. The cells constituting each row are wired in parallel. The rows are wired in series and an equalizing network of (1) n?1 capacitors 1, 2, 3, . . . n?1 connected in electrical series and (2) a network of switches. The switch network connects at one, first, time capacitor 1 across the parallel-connected cells of the 1st row, and capacitor 2 across the parallel-connected cells of the 2nd row, and so on until capacitor n?1 is connected across the parallel-connected cells of the [n?1]th row. The switch network connects at another, second, time capacitor 1 across the parallel-connected cells of the 2nd row, and capacitor 2 across the parallel-connected cells of the 3rd row, and so on until capacitor n?1 is connected across the parallel-connected cells of the nth row. This causes the voltage across each row to be substantially equal to the voltage across every other row.

Abstract: A sawtooth waveform generator includes an operational amplifier that generates a ramp signal. The ramp signal charges a capacitor connected between the output of the operational amplifier and the inverting input of the operational amplifier. The inverting input is maintained at a substantially constant voltage, which provides a substantially constant charging current through a timing resistor. The connections to the capacitor are switched when the ramp voltage reaches a predetermined level. A control circuit switches the connections to the capacitor in response to a voltage on one terminal of the capacitor to assure that the connections to the capacitor are switched to a configuration to cause the direction of current flow through the capacitor to be reversed as a result of the switching.

Abstract: An efficient ramp generator uses a reversing switch array to couple a timing capacitor in alternating polarities between an input terminal and an output terminal of an operational amplifier to generate a periodic ramp signal without discharging the timing capacitor between voltage ramps. The reversing switch array includes at least four semiconductor switches controlled by a flip-flop circuit or a latch circuit. The flip-flop circuit or the latch circuit can be driven by an external clock signal or an internal clock signal with a variable frequency.

Abstract: High voltage switches are configured with a junction transistor driven with a transformer coupled AC drive signal in the common base configuration or driven by a capacitor coupled charge pump. The high voltage switches may be configured as half wave or full wave switches wherein the junction transistor is driven during one or both half cycles of the AC drive signal. Bipolar switches that can stand off high DC voltage of either polarity, or that can stand off high AC voltage, are configured from two junction transistors with their bases connected and their emitters connected. These switches may also be driven in full wave or half wave mode, by a transformer or by single or dual capacitive charge pumps. Either NPN or PNP transistors may be used. Example drive circuits, which can be constructed as low voltage integrated circuits, are given for all of the switch types.

Abstract: An apparatus and methods for balancing current in multiple negative impedance gas discharge lamp loads. Embodiments advantageously include balancing transformer configurations that are relatively cost-effective, reliable, efficient, and good performing. Embodiments include configurations that are applicable to any number of gas discharge tubes, such as cold cathode fluorescent lamps. The balancing transformer configuration techniques permit a relatively small number of power inverters, such as one power inverter, to power multiple lamps in parallel. One embodiment of a balancing transformer includes a safety winding which can be used to protect the balancing transformer in the event of a lamp failure and can be used to provide an indication of a failed lamp.

Abstract: An efficient and flexible current-mode driver delivers power to one or more light sources in a backlight system. In one application, the current-mode driver is configured as an inverter with an input current regulator, a non-resonant polarity-switching network, and a closely-coupled output transformer. The input current regulator can output a regulated current source in a variety of programmable wave shapes. The current-mode driver may further include a rectifier circuit and a second polarity-switching network between the closely-coupled output transformer and a lamp load. In another application, the current-mode driver delivers power to a plurality of light sources in substantially one polarity by providing a regulated current to a network of time-sharing semiconductor switches coupled in series with different light sources coupled across each semiconductor switch.

Abstract: An apparatus and methods for balancing current in multiple negative impedance gas discharge lamp loads. Embodiments advantageously include balancing transformer configurations that are relatively cost-effective, reliable, efficient, and good performing. Embodiments include configurations that are applicable to any number of gas discharge tubes, such as cold cathode fluorescent lamps. The balancing transformer configuration techniques permit a relatively small number of power inverters, such as one power inverter, to power multiple lamps in parallel. One embodiment of a balancing transformer includes a safety winding which can be used to protect the balancing transformer in the event of a lamp failure and can be used to provide an indication of a failed lamp.

Abstract: An efficient and flexible current-mode driver delivers power to one or more light sources in a backlight system. In one application, the current-mode driver is configured as an inverter with an input current regulator, a non-resonant polarity-switching network, and a closely-coupled output transformer. The input current regulator can output a regulated current source in a variety of programmable wave shapes. The current-mode driver may further include a rectifier circuit and a second polarity-switching network between the closely-coupled output transformer and a lamp load. In another application, the current-mode driver delivers power to a plurality of light sources in substantially one polarity by providing a regulated current to a network of time-sharing semiconductor switches coupled in series with different light sources coupled across each semiconductor switch.

Abstract: An efficient and flexible current-mode driver delivers power to one or more light sources in a backlight system. In one application, the current-mode driver is configured as an inverter with an input current regulator, a non-resonant polarity-switching network, and a closely-coupled output transformer. The input current regulator can output a regulated current source in a variety of programmable wave shapes. The current-mode driver may further include a rectifier circuit and a second polarity-switching network between the closely-coupled output transformer and a lamp load. In another application, the current-mode driver delivers power to a plurality of light sources in substantially one polarity by providing a regulated current to a network of time-sharing semiconductor switches coupled in series with different light sources coupled across each semiconductor switch.

Abstract: An efficient and flexible current-mode driver delivers power to one or more light sources in a backlight system. In one application, the current-mode driver is configured as an inverter with an input current regulator, a non-resonant polarity-switching network, and a closely-coupled output transformer. The input current regulator can output a regulated current source in a variety of programmable wave shapes. The current-mode driver may further include a rectifier circuit and a second polarity-switching network between the closely-coupled output transformer and a lamp load. In another application, the current-mode driver delivers power to a plurality of light sources in substantially one polarity by providing a regulated current to a network of time-sharing semiconductor switches coupled in series with different light sources coupled across each semiconductor switch.

Abstract: An apparatus and methods for balancing current in multiple negative impedance gas discharge lamp loads. Embodiments advantageously include balancing transformer configurations that are relatively cost-effective, reliable, and efficient. Embodiments include configurations that are applicable to an unrestrained number of gas discharge tubes, such as cold cathode fluorescent lamps. The balancing transformer configuration techniques permit a relatively small number of power inverters, such as one power inverter, to power multiple paralleled lamps or paralleled groups of lamps with balancing transformers coupling the lamps or groups of lamps in a zigzag topology. One embodiment of a balancing transformer includes a safety winding which can be used to protect the balancing transformer in the event of a lamp failure and can be used to provide an indication of a failed lamp.

Abstract: An incremental distributed driver divides power delivered to multiple lamps into two power delivery stages. The first power delivery stage operates in voltage-mode to provide a partial operating voltage to the lamps. The second power delivery stage operates in current-mode to regulate current levels for each of the lamps and to provide additional operating voltages for the respective lamps. Each of the power delivery stages includes a polarity-switching network and a common set of driving signals from a controller can be used to drive the polarity-switching networks of both power delivery stages. The first power delivery stage delivers a majority of the power to the lamps and the second power delivery stage facilitates control of individual lamps while providing the remaining power to the lamps.

Abstract: A push-pull driver for powering fluorescent lamps in a backlight system includes a transformer with three primary windings to realize the advantages of both a push-pull switching topology and a full-bridge switching topology. The first and the second primary windings alternately conduct currents in opposite polarities to generate an alternating current signal to power one or more lamps coupled to a secondary winding of the transformer. The third primary winding is short-circuited to preserve energy stored in the transformer in a null state when both the first and the second primary windings are not conducting.

Abstract: An apparatus and methods for balancing current in multiple negative impedance gas discharge lamp loads. Embodiments advantageously include balancing transformer configurations that are relatively cost-effective, reliable, efficient, and good performing. Embodiments include configurations that are applicable to any number of gas discharge tubes, such as cold cathode fluorescent lamps. The balancing transformer configuration techniques permit a relatively small number of power inverters, such as one power inverter, to power multiple lamps in parallel. One embodiment of a balancing transformer includes a safety winding which can be used to protect the balancing transformer in the event of a lamp failure and can be used to provide an indication of a failed lamp.

Abstract: An apparatus and methods for balancing current in multiple negative impedance gas discharge lamp loads. Embodiments advantageously include balancing transformer configurations that are relatively cost-effective, reliable, and efficient. Embodiments include configurations that are applicable to an unrestrained number of gas discharge tubes, such as cold cathode fluorescent lamps. The balancing transformer configuration techniques permit a relatively small number of power inverters, such as one power inverter, to power multiple paralleled lamps or paralleled groups of lamps with balancing transformers coupling the lamps or groups of lamps in a zigzag topology. One embodiment of a balancing transformer includes a safety winding which can be used to protect the balancing transformer in the event of a lamp failure and can be used to provide an indication of a failed lamp.

Abstract: A coil has foil conductor windings which are formed into self leads and provide a stable mount to a printed circuit board or the like. End portions of the foil windings, having conductive opposite sides, are cut and formed into stacks. The stack configuration forms the self leads of the foil winding and facilitates the winding's exit from the coil. The self leads extend from the coil and are formed to reach to the printed circuit board (PCB). The self leads are strong enough to mount the coil to the PCB. The ends of the self leads are trimmed to fit through holes in the PCB. After insertion, the layers of the self leads are bent in opposing directions to substantially block the hole, prevent extraction, and prevent solder from flowing through the holes. The self leads are then soldered to the board. A bobbin having discontinuous flanges facilitates the exits of the self leads from the coil. The invention is useful in coils, inductors, transformers, and the like.

Abstract: A coil has foil conductor windings which are formed into self leads and provide a stable mount to a printed circuit board or the like. End portions of the foil windings, having conductive opposite sides, are cut and formed into stacks. The stack configuration forms the self leads of the foil winding and facilitates the winding's exit from the coil. The self leads extend from the coil and are formed to reach to the printed circuit board (PCB). The self leads are strong enough to mount the coil to the PCB. The ends of the self leads are trimmed to fit through holes in the PCB. After insertion, the layers of the self leads are bent in opposing directions to substantially block the hole, prevent extraction, and prevent solder from flowing through the holes. The self leads are then soldered to the board. A bobbin having discontinuous flanges facilitates the exits of the self leads from the coil. The invention is useful in coils, inductors, transformers, and the like.

Abstract: A coil has foil conductor windings which are formed into self leads and provide a stable mount to a printed circuit board or the like. End portions of the foil windings are cut and formed into stacks. The stack configuration forms the self leads of the foil winding and facilitates the winding's exits from the coil. The self leads extend from the coil and are formed to reach to the printed circuit board (PCB). The self leads are strong enough to mount the coil to the PCB. The ends of the self leads are trimmed to fit through holes in the PCB. After insertion, the layers of the self leads are bent in opposing directions to substantially block the hole, prevent extraction, and prevent solder from flowing through the holes. The self leads are then soldered to the board. A bobbin having discontinuous flanges facilitates the exits of the self leads from the coil. The invention is useful in coils, inductors, transformers, and the like.