Abstract: A control circuit for a switch unit of a clocked power supply receives an auxiliary signal from a resonant transformer driven by the switch unit and detects reference crossing moments when the auxiliary signal crosses a reference value. A driver is controllable to switch the switch unit, and a synchronization circuit synchronizes 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 circuit receives information about the reference crossing moments and provides 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.

Abstract: 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 IL, wherein fluctuations in the lamp current IL caused by the residual ripple of the DC input voltage are compensated by a variation in the switch-on times and/or switch-off times of the switching elements QH, QL of the DC/AC inverter.

Abstract: 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.

Abstract: 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. The 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.

Abstract: The invention involves 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, and comprises an input for receiving an auxiliary signal from the resonant transformer arrangement. The invention also includes a resonance converter that 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: The invention relates to a method for detection of non-zero-voltage switching operation of a lamp ballast, which has a half-bridge circuit with a first and a second semiconductor switching element, a resonant tuned circuit which is connected to one output of the half-bridge circuit, and a snubber capacitance, which is connected in parallel with one of the semiconductor switching elements. The method has the following method steps: provision of a voltage measurement signal (Vs) which is dependent on a voltage at the output of the half-bridge, evaluation of the voltage measurement signal (Vs) in each case before switching-on times of at least one of the first and second semiconductor switching elements by comparison of the voltage measurement signal (Vs) with a reference value (Vref) for detection of the non-zero-voltage switching operation.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: The invention relates to a method for provision of a drive signal for a switch which controls the current drawn by an inductive energy storage element in a power factor correction circuit, in which a control signal which controls the power consumption is available. One drive cycle of the switch comprises: detection of a predetermined storage state of the inductive energy storage element; when the predetermined storage state of the storage element is detected, production of a switching-on level for the drive signal for a regular switched-on duration which is dependent on the control signal or for a maximum switched-on duration which is dependent on an input voltage, when the regular switched-on duration is greater than the maximum switched-on duration; and production of a switching-off level for the drive signal for a switched-off duration until the next detection of the predetermined storage state.

Abstract: A drive circuit for at least one fluorescent lamp has a half-bridge circuit for production of a supply voltage a resonant tuned circuit coupled to the half-bridge circuit and to which the at least one fluorescent lamp can be connected, a diagnosis circuit with a resistance element coupled to the resonant tuned circuit, at least one current/voltage converter connected to the resistance element that produces at least one measurement voltage from a current flowing through the resistance element, and an evaluation circuit which is connected to the current/voltage converter and is supplied with the at least one measurement voltage and to a method for diagnosis of a fluorescent lamp.

Abstract: 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 synchronizer 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.

Abstract: The present invention relates to a drive circuit for a switch (T) connected to a rectifier arrangement in a switching converter which provides an output voltage (Vout) from an input voltage (Vin), the drive circuit having the following features: a controller arrangement (40) having at least one control amplifier (OTA1) and a compensation network (41) having at least one capacitor (C4, C5), a signal dependent on the output voltage (Vout) being fed to said controller arrangement and the latter providing a control signal (S4), a protection circuit (30), which is designed to detect at least one critical state of the switching converter and which provides a protection signal (S3) in a manner dependent on the presence of a critical state, the protection circuit (30) having a discharge circuit (32) coupled to the compensation network (41), a signal generating circuit (20), to which the control signal (S4) and the protection signal (S3) are fed and which provides a drive signal (S5) having drive pulses according t

Abstract: The invention relates to a method for detection of non-zero-voltage switching operation of a lamp ballast, which has a half-bridge circuit with a first and a second semiconductor switching element, a resonant tuned circuit which is connected to one output of the half-bridge circuit, and a snubber capacitance, which is connected in parallel with one of the semiconductor switching elements. The method has the following method steps: provision of a voltage measurement signal (Vs) which is dependent on a voltage at the output of the half-bridge, evaluation of the voltage measurement signal (Vs) in each case before switching-on times of at least one of the first and second semiconductor switching elements by comparison of the voltage measurement signal (Vs) with a reference value (Vref) for detection of the non-zero-voltage switching operation. The invention also relates to a ballast for carrying out a method such as this.

Abstract: The invention relates to a drive circuit for at least one fluorescent lamp (10) which has the following features: a half-bridge circuit (Q1, Q2) for production of a supply voltage (V2), a resonant tuned circuit (L1, C1) which is coupled to the half-bridge circuit (Q1, Q2) and to which the at least one fluorescent lamp (10) can be connected, a diagnosis circuit (30) with a resistance element (R1) which is coupled to the resonant tuned circuit (L1, C1), at least one current/voltage converter (31) which is connected to the resistance element (R1) and produces at least one measurement voltage (V31; V311, V312) from a current (I1) flowing through the resistance element, and an evaluation circuit (32) which is connected to the current/voltage converter (31) and is supplied with the at least one measurement voltage (V31; V311, V312), and to a method for diagnosis of a fluorescent lamp.

Abstract: A semiconductor component contains two semiconductor bodies, which are spatially separated from one another and electrically interconnected. A compensation MOS field effect transistor is provided as the first semiconductor body, and a silicon carbide Schottky diode is provided as the second semiconductor body. Consequently, the semiconductor component can advantageously be produced significantly more compactly and more cost-effectively, since both the compensation MOS field-effect transistor and the silicon carbide Schottky diode contribute to a significant reduction of power loss.