| Patent application number | Description | Published |
|---|
| 20080252268 | Method for actuation, and actuating circuit for a switch in a power factor correction circuit - The document describes a method and an actuating circuit for actuating a switch regulating the power consumption in a power factor correction circuit which has input terminals for applying an input voltage and output terminals for providing an output voltage. In this case, the switch is cyclically turned on for an on-time and turned off for an off-time, respectively, with the on-time having a first on-time period and a second on-time period which is directly adjacent to the first on-time period. A length for the first on-time period is in this case dependent on the control signal, and a length for the second on-time period is proportional, at least for a prescribed range of values for an instantaneous value of the input voltage, to a quotient with a first first-degree function for this instantaneous value in the denominator and a second first-degree function for the instantaneous value in the numerator, with function values for the first function increasing as the instantaneous value rises. | 10-16-2008 |
| 20080252269 | Actuating circuit - Disclosed is an actuating circuit and method for actuating a switch regulating the power consumption in a power factor correction circuit having input terminals for applying an input voltage and output terminals for providing an output voltage. The switch is cyclically turned on for an on-time and turned off for an off-time, the on-time having a first on-time period and a second on-time period directly adjacent to the first on-time period. A length for the first on-time period is dependent on the control signal, and a length for the second on-time period is proportional, at least for a prescribed range of values for an instantaneous value of the input voltage, to a quotient with a first first-degree function for the instantaneous value in the denominator and a second first-degree function for the instantaneous value in the numerator, with function values for the first function increasing as the instantaneous value rises. | 10-16-2008 |
| 20080265900 | Method and Apparatus for Monitoring the Operation of a Gas Discharge Lamp - For monitoring the operation of a gas discharge lamp operated with an AC voltage, a lamp voltage signal is generated which is dependent on the voltage dropped across the gas discharge lamp during operation. Said lamp voltage signal is filtered with an attenuation that is different for a DC component and for a component having the frequency of the AC voltage, whereupon a positive and negative peak value of the filtered lamp voltage signal are determined. For monitoring the gas discharge lamp, an average value of the two peak values is determined and compared with a limit value, and a difference value between the two peak values is determined and compared with a limit value. | 10-30-2008 |
| 20090021174 | Controlling a Lamp Ballast - A method and apparatus for providing electrical current to a lamp, detecting a power supply voltage outage, detecting a return of the power supply voltage, determining how long the power supply voltage outage lasted, and preheating the lamp responsive to determining that the power supply voltage outage lasted greater than a threshold amount of time. | 01-22-2009 |
| 20090256487 | Method for detection of non-zero-voltage switching operation of a ballast of fluorescent lamps, and ballast - A method detects a non-zero-voltage switching operation of a lamp ballast, the lamp ballast including a half-bridge circuit with a first and a second semiconductor switching element, a resonant circuit connected to the half-bridge circuit, and a snubber capacitance connected in parallel with one of the semiconductor switching elements. The method includes obtaining a voltage measurement signal representative of a voltage at an output of the half-bridge circuit. The method also includes providing a comparison signal representative of a comparison of the voltage measurement signal with a reference value. The method further includes evaluating the comparison signal in each case before the first semiconductor element is switched on and in each case before the second semiconductor element is switched on, and detecting one of a first and second non-zero-switching operations based on these evaluations. | 10-15-2009 |
| 20100135049 | CONTROL CIRCUIT FOR A SWITCH UNIT OF A CLOCKED POWER SUPPLY CIRCUIT, AND RESONANCE CONVERTER - A control circuit for a switch unit of a clocked power supply circuit, the switch unit being designed to effect input-side excitation of a resonant transformer arrangement, comprises an input for receiving an auxiliary signal from the resonant transformer arrangement. The auxiliary signal exhibits an essentially fixed phase relation to a load alternating current flowing through a resonant circuit of the transformer arrangement. The control circuit further comprises a phase detector designed to detect reference crossing moments when the auxiliary signal crosses a predefined reference value, a driver controllable to switch the switch unit, and a synchronization means designed to synchronize a turn-on of the switch unit by the driver with regard to a phase position with the auxiliary signal so as to achieve a turn-on of the switch unit within a predetermined time interval around a zero crossing of a voltage present across the switch unit, or of a current flowing through the switch unit. The synchronization means is further designed to receive information about the reference crossing moments from the phase detector, and to provide a turn-on signal to the driver with a fixed phase delay at the reference crossing moments, so as to define turn-on moments at which the driver is to turn on the switch unit. The control circuit further comprises a detector designed to determine an amplitude information which depends on an amplitude or a mean value of the auxiliary signal, and a regulator designed to change an operating frequency in dependence on the amplitude information supplied by the detector, and to determine a period duration between turn-off moments at which the driver is to turn off the switch unit as a reciprocal of the operating frequency. An inventive resonance converter enables independent control of frequency and turn-on moments, or duty cycle, and thus enables a particularly efficient operation of the resonance converter, and a particularly precise regulation. | 06-03-2010 |
| 20100327771 | METHOD FOR CONTROLLING GAS DISCHARGE LAMPS - The invention relates to a method and a device for controlling gas discharge lamps using a direct current/alternating current inverter (DC/AC inverter) that is operated at a predetermined frequency and that generates an AC output voltage U for operating the gas discharge lamps from a DC input voltage which has a residual ripple. According to the invention, the DC/AC inverter is operated in zero voltage switching (ZVS) mode, wherein the DC input voltage is used as the control variable for the lamp current I | 12-30-2010 |
