Abstract:
A method according to one embodiment may include providing power to at least one light source. The method of this embodiment may also include detecting the frequency of at least one vertical synchronization signal, among a plurality of different synchronization signals, and controlling the power to at least one light source based on, at least in part, the detected frequency of at least one vertical synchronization signal. Of course, many alternatives, variations, and modifications are possible without departing from this embodiment.
Abstract:
A method according to one embodiment may include providing power to at least one light source. The method of this embodiment may also include detecting the frequency of at least one vertical synchronization signal, among a plurality of different synchronization signals, and controlling the power to at least one light source based on, at least in part, the detected frequency of at least one vertical synchronization signal. Of course, many alternatives, variations, and modifications are possible without departing from this embodiment.
Abstract:
A power supply system is provided for a multiple lamp LCD panel. In one aspect, the power supply includes a plurality of transformers for driving a plurality of respective CCFLs. The primary sides of each transformer are coupled in series to thereby reduce the stress on each transformer. For LCD panels that include longer CCFLs, a power supply is provided that includes a plurality of transformers for driving a plurality of respective CCFLs. The primary sides of each transformer are coupled in series and each lamp is coupled to two secondary sides of the transformers, thereby reducing the problems associated with longer CCFL tubes. In any of the embodiments, the power supply can be adapted to convert a high voltage DC signal to high voltage AC used to power the lamps.
Abstract:
A CCFL power converter circuit is provided using a high-efficiency zero-voltage-switching technique that eliminates switching losses associated with the power MOSFETs. An optimal sweeping-frequency technique is used in the CCFL ignition by accounting for the parasitic capacitance in the resonant tank circuit. Additionally, the circuit is self-learning and is adapted to determine the optimum operating frequency for the circuit with a given load. An over-voltage protection circuit can also be provided to ensure that the circuit components are protected in the case of open-lamp condition.
Abstract:
A CCFL power converter circuit is provided using a high-efficiency zero-voltage-switching technique that eliminates switching losses associated with the power MOSFETs. An optimal sweeping-frequency technique is used in the CCFL ignition by accounting for the parasitic capacitance in the resonant tank circuit. Additionally, the circuit is self-learning and is adapted to determine the optimum operating frequency for the circuit with a given load. An over-voltage protection circuit can also be provided to ensure that the circuit components are protected in the case of open-lamp condition.
Abstract:
The present invention provides an integrated LCD panel power supply formed on a single printed circuit board. The integrated power supply includes at least one DC/AC control unit, at least one DC/DC buck converter unit and at least one DC/DC boost control unit. Each unit supplies power to an associated function of said LCD. The integrated power supply may also include an oscillator circuit generating a clock signal, and the clock signal is supplied to each unit thereby synchronizing the operation of each unit. The single PCB approach of the present invention eliminates the need for additional wiring between printed circuit boards and thereby eliminates or substantially reduces noise issues associated with such wiring.
Abstract:
A sequential burst mode regulation system to deliver power to a plurality of loads. In the exemplary embodiments, the system of the present invention generates a plurality of phased pulse width modulated signals from a single pulse width modulated signal, where each of the phased signals regulates power to a respective load. Exemplary circuitry includes a PWM signal generator, and a phase delay array that receives a PWM signal and generates a plurality of phased PWM signals which are used to regulate power to respective loads. A frequency selector circuit can be provided that sets the frequency of the PWM signal using a fixed or variable frequency reference signal.
Abstract:
A method according to one embodiment may include supplying power to an LED array having at least a first string of LEDs and a second string of LEDs coupled in parallel, each of the strings includes at least two LEDs. The method of this embodiment may also include comparing a first feedback signal from the first string of LEDs and a second feedback signal from the second string of LEDs. The first feedback signal is proportional to current in said first string of LEDs and said second feedback signal is proportional to current in said second string of LEDs. The method of this embodiment may also include controlling a voltage drop of at least the first string of LEDs to adjust the current of the first string of LEDs relative to the second string of LEDs, based on, at least in part, the comparing of the first and second feedback signals. Of course, many alternatives, variations, and modifications are possible without departing from this embodiment.
Abstract:
A driving circuit for controlling power of a light source includes a power converter coupled to a power source and the light source, and a dimming controller coupled to the power converter. The power converter can receive power from the power source and provide a regulated power to the light source. The power converter includes a control switch coupled in series with the light source. The dimming controller can monitor a power switch coupled between the power source and the driving circuit, and receive a dimming request signal and a dimming termination signal. The dimming request signal can indicate a first set of operations of the power switch. The dimming termination signal can indicate a second set of operations of the power switch. The dimming controller can continuously adjust the regulated power from the power converter by controlling the control switch if the dimming request signal is received, and can stop adjusting the regulated power from the power converter if the dimming termination signal is received.
Abstract:
A method according to one embodiment may include generating, by a controller, a plurality of control signals to control operations of inverter circuitry to generate an AC signal from a DC signal. The method of this embodiment may also include using the control signals generated by the controller to also control operations of power factor correction (PFC) circuitry, via the inverter circuitry, to enable the PFC circuitry to generate power factor correction of an input source coupled to the PFC circuitry and the inverter circuitry. Of course, many alternatives, variations, and modifications are possible without departing from this embodiment.