Abstract: In one embodiment, and LED control circuit may be configured to monitor the value of currents in two or more strings of series connected LEDs, and to adjust the currents to be substantially equal to each other.

Abstract: At least one embodiment is directed to a semiconductor voltage controller comprising: a start-mode circuit associated with a start-mode; and an off-mode circuit associated with an off-mode, where the voltage controller can be configured to receive a feedback signal and an off-mode signal from a single input and provide an output voltage, where the voltage controller can be configured to be in the off-mode when the feedback signal is less than a skip level and the feedback signal is less than a HV control level, and where the voltage controller can be configured to be in start mode when the feedback signal is greater than HV control level and Vcc is below a Vcc-start.

Abstract: In one embodiment, and LED control circuit may be configured to monitor the value of currents in two or more strings of series connected LEDs, and to adjust the currents to be substantially equal to each other.

Abstract: In accordance with an embodiment, a method for controlling a circuit includes controlling pulse width modulation on a primary side of a quasi-resonant controller to achieve continuous current mode operation from a synchronous rectification controller on a secondary side.

Abstract: In one embodiment, a method of forming a conditioning circuit includes configuring an output biasing network to provide a biasing voltage to an MOS transistor to enable the MOS transistor to operate in a saturated operating mode for input voltages that are less than a threshold voltage.

Abstract: At least one embodiment is directed to a semiconductor voltage controller comprising: a start-mode circuit associated with a start-mode; and an off-mode circuit associated with an off-mode, where the voltage controller can be configured to receive a feedback signal and an off-mode signal from a single input and provide an output voltage, where the voltage controller can be configured to be in the off-mode when the feedback signal is less than a skip level and the feedback signal is less than a HV control level, and where the voltage controller can be configured to be in start mode when the feedback signal is greater than HV control level and Vcc is below a Vcc-start.

Abstract: At least one embodiment is directed to a semiconductor voltage controller comprising: a start-mode circuit associated with a start-mode; and an off-mode circuit associated with an off-mode, where the voltage controller can be configured to receive a feedback signal and an off-mode signal from a single input and provide an output voltage, where the voltage controller can be configured to be in the off-mode when the feedback signal is less than a skip level and the feedback signal is less than a HV control level, and where the voltage controller can be configured to be in start mode when the feedback signal is greater than HV control level and Vcc is below a Vcc-start.

Abstract: A method and circuit for suppressing a bias current and decreasing power consumption. A current suppression circuit is coupled to a circuit element, which is capable of conducting the bias current. Coupling the current suppression circuit to the circuit element forms a node. In one operating mode, the current suppression circuit applies a voltage to the node in response to a heavy load. In another operating mode, the current suppression circuit lowers the voltage at the node in response to a light load or no load. Lowering the voltage at the node decreases the flow of bias current through the circuit element thereby lowering power loss.

Abstract: A power control circuit and method of formation is provided, which in one embodiment includes a low voltage detection circuit to process a rectified input voltage from at least one alternating current (AC) voltage source and to output a low voltage indication signal upon detection of an initiation of an increase in the rectified input voltage; and a driver circuit configured to receive a signal representative of the low voltage indication signal and, in response, to output a drive signal to the switch control input of the power switch to turn on the power switch.

Abstract: In accordance with an embodiment, a method for controlling a circuit includes controlling pulse width modulation on a primary side of a quasi-resonant controller to achieve continuous current mode operation from a synchronous rectification controller on a secondary side.

Abstract: A power control circuit and method of formation is provided, which in one embodiment includes a low voltage detection circuit to process a rectified input voltage from at least one alternating current (AC) voltage source and to output a low voltage indication signal upon detection of an initiation of an increase in the rectified input voltage; and a driver circuit configured to receive a signal representative of the low voltage indication signal and, in response, to output a drive signal to the switch control input of the power switch to turn on the power switch.

Abstract: In one embodiment, a method of forming a conditioning circuit includes configuring an output biasing network to provide a biasing voltage to an MOS transistor to enable the MOS transistor to operate in a saturated operating mode for input voltages that are less than a threshold voltage.

Abstract: At least one embodiment is directed to a semiconductor voltage controller comprising: a start-mode circuit associated with a start-mode; and an off-mode circuit associated with an off-mode, where the voltage controller can be configured to receive a feedback signal and an off-mode signal from a single input and provide an output voltage, where the voltage controller can be configured to be in the off-mode when the feedback signal is less than a skip level and the feedback signal is less than a HV control level, and where the voltage controller can be configured to be in start mode when the feedback signal is greater than HV control level and Vcc is below a Vcc-start.

Abstract: A lighting system comprising a first plurality of fluorescent lamps (17) constituted by a first and a second lamp (20, 21) having a first common terminal (18) which is connected via a first capacitor (22) to a first terminal (12) of a voltage source (11). The system further comprises a second plurality of fluorescent lamps (29) constituted by a third and a fourth lamp (32, 33) having a first common terminal (30) which is connected via a second capacitor (34) to the first terminal (12) of a voltage source (11). The second terminals of the first lamp (20) and third lamp (32) are connected to a first terminal (24) of a third capacitor (25), said third capacitor (25) being connected with its second terminal to the second terminal (13) of the voltage source (11). The second terminals of the second lamp (21) and fourth lamp (33) are connected to a first terminal (36) of a fourth capacitor (37), the fourth capacitor (37) being connected with its second terminal to the second terminal (13) of the voltage source (11).

Abstract: A method and circuit for suppressing a bias current and decreasing power consumption. A current suppression circuit is coupled to a circuit element, which is capable of conducting the bias current. Coupling the current suppression circuit to the circuit element forms a node. In one operating mode, the current suppression circuit applies a voltage to the node in response to a heavy load. In another operating mode, the current suppression circuit lowers the voltage at the node in response to a light load or no load. Lowering the voltage at the node decreases the flow of bias current through the circuit element thereby lowering power loss.

Abstract: The circuit arrangement has a power supply unit, a mains switch and a switching element, for example a relay, that bridges a first switching contact of the mains switch. A load is coupled to a control terminal of the switching element, so that when the control voltage is turned off for the purpose of opening the switching element, the load is simultaneously turned off. The circuit arrangement contains a microprocessor, in particular, which is supplied with an operating voltage by the power supply unit, and which is coupled to the control terminal of the switching element for control of the switching element. The load is a fan, for example, which is switched off in a delayed manner when the circuit arrangement is switched off by means of the mains switch.

Abstract: A lighting system comprising a first plurality of fluorescent lamps (17) constituted by a first and a second lamp (20, 21) having a first common terminal (18) which is connected via a first capacitor (22) to a first terminal (12) of a voltage source (11). The system further comprises a second plurality of fluorescent lamps (29) constituted by a third and a fourth lamp (32, 33) having a first common terminal (30) which is connected via a second capacitor (34) to the first terminal (12) of a voltage source (11). The second terminals of the first lamp (20) and third lamp (32) are connected to a first terminal (24) of a third capacitor (25), said third capacitor (25) being connected with its second terminal to the second terminal (13) of the voltage source (11). The second terminals of the second lamp (21) and fourth lamp (33) are connected to a first terminal (36) of a fourth capacitor (37), the fourth capacitor (37) being connected with its second terminal to the second terminal (13) of the voltage source (11).

Abstract: The switched mode power supply contains a transformer, which has a primary winding and at least one secondary winding, a switching transistor in series with the primary winding and a control circuit for controlling an output voltage of the switched mode power supply. The control circuit contains an oscillator, whose oscillation frequency can be set via a terminal, and which is coupled to a secondary winding of the transformer. The wiring for the terminal is connected such that the switched mode power supply starts up at a relatively low oscillation frequency once it has been connected, and, during operation when an additional voltage is supplied to the input via the secondary winding, the oscillation frequency of the switched mode power supply is increased. The terminal is connected in particular via a bandpass filter to a voltage generated by the secondary winding.

Abstract: The circuit arrangement has a power supply unit, a mains switch and a switching element, for example a relay, that bridges a first switching contact of the mains switch. A load is coupled to a control terminal of the switching element, so that when the control voltage is turned off for the purpose of opening the switching element, the load is simultaneously turned off. The circuit arrangement contains a microprocessor, in particular, which is supplied with an operating voltage by the power supply unit, and which is coupled to the control terminal of the switching element for control of the switching element. The load is a fan, for example, which is switched off in a delayed manner when the circuit arrangement is switched off by means of the mains switch.

Abstract: Embodiments of the invention provide a power supply unit that operates in a standby mode and in a normal mode. The power supply unit comprises a first power supply providing output voltages during the standby mode and a second power supply providing output voltages during the normal mode. A pre-converter provides a stabilized supply voltage for the first and second power supply. The pre-converter operates as an up-converter during the normal operation mode and is switched off during the standby mode together with the second power supply.