Abstract: An apparatus includes a controller (such as associated with a power converter). The controller is operative to receive input control settings. Based on the input control settings, the controller controls a magnitude of an output current generated by the power converter. The output current from the power converter powers light emitting hardware. The controller transitions between operating the power converter in an asynchronous mode and a synchronous mode to produce the output current.

Abstract: An apparatus includes a controller (such as associated with a power converter). The controller is operative to receive input control settings. Based on the input control settings, the controller controls a magnitude of an output current generated by the power converter. The output current from the power converter powers light emitting hardware. The controller transitions between operating the power converter in an asynchronous mode and a synchronous mode to produce the output current.

Abstract: According to an embodiment, a power supply system has a primary side and a secondary side. An input terminal on the primary side is operable to receive an input voltage. An output terminal on the secondary side is operable to be connected to a load for providing current thereto. Circuitry is provided which is operable to regulate the power supply system from the primary side so that the current provided to the load at the output terminal is substantially constant.

Abstract: According to an embodiment, a power supply system has a primary side and a secondary side. An input terminal on the primary side is operable to receive an input voltage. An output terminal on the secondary side is operable to be connected to a load for providing current thereto. Circuitry is provided which is operable to regulate the power supply system from the primary side so that the current provided to the load at the output terminal is substantially constant.

Abstract: The invention relates to a supply circuit for a load, and in particular to an electronic ballast for a lamp having such a supply circuit. In order to drive a switching transistor T1 of the supply circuit, a forcing circuit ZS is used which is supplied by the supply circuit. At the start of operation, an oscillation of an oscillator circuit OS, which can preferably serve as an amplifier for the forcing circuit ZS in the continuous operating mode, is used for driving.

Abstract: An operating circuit for a discharge lamp (LP) having preheatable electrodes includes a device (C14, T11, T12, T13, G) for preheating the electrodes. The device includes a resonant circuit (C14, T11) which oscillates during preheating. During operation, the operating circuit produces an AC voltage having a frequency that is moved through a frequency range, records the response of the resonant circuit (C14, T11) by measuring an electrical variable (UC14), and identifies the resonant frequency of the resonant circuit (C14, T11) from the electrical variable (UC14), and preheats the electrodes by setting the frequency of the AC voltage to the resonant frequency.

Abstract: The invention relates to a novel operating device for lamps, in particular low-pressure gas discharge lamps, in which a SEPIC converter is used for charging a storage transistor from an AC voltage supply. In this case, the SEPIC converter is regulated to an output quantity as regulated variable, its operating frequency being altered. Preferably, only the switch-on time and not the switch-off time of the switching transistor of the SEPIC converter is altered in this case.

Abstract: The invention relates to a supply circuit for a load, and in particular to an electronic ballast for a lamp having such a supply circuit. In order to drive a switching transistor T1 of the supply circuit, a forcing circuit ZS is used which is supplied by the supply circuit. At the start of operation, an oscillation of an oscillator circuit OS, which can preferably serve as an amplifier for the forcing circuit ZS in the continuous operating mode, is used for driving.

Abstract: An electronic ballast for lamps, which has an input stage that is designed as a SEPIC converter. By operating the SEPIC converter in the mode with a discontinuous current profile, a slow microcontroller can be used for the control.

Abstract: A method and circuit arrangement for operating a fluorescent lamp (LA), comprising a half-bridge arrangement (12) whose output signal can be fed to a load circuit (LK; 16), it being possible to connect a fluorescent lamp (LA) with filament electrodes (W1, W2) to the load circuit (LK; 16), a preheating device (L21, L22, CR) for preheating the filament electrodes (W1, W2) of the fluorescent lamp (LA), and a power determining device (20) for determining a preheating power value that represents a measure of the power that is converted in the filament electrodes (W1, W2) during preheating, wherein the power determining device (20) can be used to determine the power flowing into the load circuit (LK; 16) during preheating.

Abstract: The invention relates to a novel operating device for lamps, in particular low-pressure gas discharge lamps, in which a SEPIC converter is used for charging a storage transistor from an AC voltage supply. In this case, the SEPIC converter is regulated to an output quantity as regulated variable, its operating frequency being altered. Preferably, only the switch-on time and not the switch-off time of the switching transistor of the SEPIC converter is altered in this case.

Abstract: The invention relates to an operating circuit for a low-pressure discharge lamp LP, in which the lamp electrodes can be preheated by means of a resonant circuit C14, T11. In order to determine the resonant frequency accurately and to establish the lamp type being used, a frequency range is moved through at the start of operation and the voltage is measured on a primary winding T11 of a preheating transformer.

Abstract: An electronic ballast for discharge lamps with electrode filaments. The ballast contains a frequency-selective device, which suppresses an auxiliary heating current in the electrode filaments during operation of the lamp. Heating of the electrode filaments is possible only within a narrow frequency band.

Abstract: The present invention relates to a circuit arrangement for operating a fluorescent lamp (LA), comprising a half-bridge arrangement (12) whose output signal can be fed to a load circuit (LK; 16), it being possible to connect a fluorescent lamp (LA) with filament electrodes (W1, W2) to the load circuit (LK; 16), a preheating device (L21, L22, CR) for preheating the filament electrodes (W1, W2) of the fluorescent lamp (LA), and a power determining device (20) for determining a preheating power value that represents a measure of the power that is converted in the filament electrodes (W1, W2) during preheating, wherein the power determining device (20) can be used to determine the power flowing into the load circuit (LK; 16) during preheating.

Abstract: An electronic ballast for discharge lamps with electrode filaments. The ballast contains a frequency-selective device, which suppresses an auxiliary heating current in the electrode filaments during operation of the lamp. Heating of the electrode filaments is possible only within a narrow frequency band.

Abstract: An electronic ballast for lamps, which has an input stage that is designed as a SEPIC converter. By operating the SEPIC converter in the mode with a discontinuous current profile, a slow microcontroller can be used for the control.

Abstract: The invention relates to a circuit arrangement for operating at least one discharge lamp (LP) on a half-bridge inverter (Q1, Q2), having at least one coupling capacitor (C3) and having a switch-off device (T1, A) which permanently switches off the half-bridge inverter (Q1, Q2) when the lamp (LP) refuses to start. According to the invention, the circuit arrangement has first and second devices (V1, V2) for monitoring the voltage drop across the at least one coupling capacitor (C3) and for activating the switch-off device (T1, A) as a function of the voltage drop detected across the at least one coupling capacitor (C3). If the voltage across the coupling capacitor (C3) deviates substantially from its normal value, for example owing to the occurrence or the rectifying effect at the end of the service life of the discharge lamp (LP), the half-bridge inverter (Q1, Q2) is shut down by the switch-off device (T1, A).