Abstract: A method is proposed for influencing the electrical power of a load with the assistance of a pulse-width modulated signal, the latter including the requirement of a continuous turn-on signal. The method provides that the continuous turn-on signal is terminated by an interrupt signal and that the continuous turn-on signal is followed by a clock-pulse phase having at least one fundamental period duration of the pulse-width modulated signal, the period including a turn-off time. The occasional interruption of the pulse-width modulated signal, which is present as the continuous turn-on signal, makes it possible to detect an operational quantity of the load that only arises during a power change in the load.

Abstract: A transformer includes a divided primary winding in an isolating transformer power supply circuit and a secondary winding between the parts of the primary winding, a magnetic core having an air gap, and a bobbin surrounding the core with the individual windings applied to it, the transformer has a row of terminal posts to which the windings are connected is designed so that the primary winding is divided into at least three partial windings. The, the secondary winding that is under the highest load for the longest period of time is divided into at least two partial windings, the partial windings of this load secondary winding are enclosed by two partial windings of the minimum of three partial windings of the primary winding on the bobbin, and optionally one or more additional secondary windings are arranged outside the winding structure of the partial windings of the primary winding and load secondary winding.

Abstract: A clocked power supply circuit having an at least intermittently active load that is independent of a consumer, in particular for supplying power to gas-discharge lamps as consumers, contains a dc/dc converter comprising a transformer. Switching elements connect the converter to a dc voltage source in the timing of a control arrangement which makes available switching signals for the switching elements as a function of the prevailing output-side load state. The transformer of the dc/dc converter is designed so that two voltages (U+, U-) of differing polarity and magnitude, are able to be tapped off from the output side. At least one of these voltages is regulated and provided for supplying power during operation of the consumer. The at least intermittently active load can be switched to the regulated voltage.

Abstract: An arrangement for detecting the ignition of a high-pressure gas discharge lamp, in particular for use with a motor vehicle headlamp, comprising a circuit for supplying the high-pressure gas discharge lamp with burning energy, a control circuit and an ignition circuit. The ignition circuit is provided with an auxiliary voltage for the ignition. The control circuit is configured such that it detects the ignition of the high-pressure gas discharge lamp immediately via the behavior or the status of the auxiliary voltage (U.sub.H). The control circuit can be provided with a microcontroller (20). The auxiliary voltage supplied during the ignition is connected to the microcontroller in such a way that the microcontroller detects the ignition without delay. For this, the auxiliary voltage is supplied via a voltage divider (22, 23, 24) with logic potential to the external interrupt input (21) of the microcontroller.

Abstract: A voltage transformer with storage reactor (15) and with at least one circuit breaker (14, 14a, 22, 22a), in which the current flowing in the storage reactor (15) establishes the turning off and turning on of the circuit breaker (14, 14a, 22, 22a). A comparator (33) compares the current flowing in the storage reactor (15) to a stipulated threshold value. The circuit breaker (14, 14a, 22, 22a) is when the threshold value is traversed. A timer (17, 17a, 17b), after a voltage jump occurs on storage reactor (15), keeps the circuit breaker (14, 14a, 22, 22a) in the existing switching state for the time fixed by the timer (17, 17a, 17b). The voltage transformer according to the invention can be built with a few discrete components in an extremely cost-favorable manner. One preferred application is given in a motor vehicle.