Abstract: An electronic ballast for a lamp having a bridge circuit, includes at least one first switch and a second switch coupled between a connection for a supply voltage and a connection for a ground potential, a center point of the bridge circuit between the first switch and second switches; a first and a second connection for a lamp the first connection coupled to the center point; and a signal evaluation unit. The evaluation unit includes a first input coupled to a signal which is at the DC voltage level of the first connection, and second input coupled to a signal which is at the DC voltage level of the second connection, the DC voltage reference potential for the evaluation unit being designed to be variable within a value range which is greater than or equal to the ground potential and is less than or equal to the supply voltage potential.

Abstract: The invention relates to a circuit arrangement for operating lamps. The circuit arrangement essentially comprises a full bridge. According to the invention, at least one inductor is connected in series with a full-bridge branch for switching load relief purposes. The circuit arrangement is preferably suitable for operation using a charge pump. PFC is thus achieved in a single-stage arrangement.

Abstract: A step-down controller has an input having a first and a second input terminal for applying an input voltage, an output having a first and a second output terminal at which an output voltage can be provided, a series circuit including a switch and an inductance which is coupled between the first input terminal and the first output terminal. The switch has a control input for applying a control signal. A first diode is coupled between a junction point between the switch and the inductance and a reference potential such that, when the inductance is freewheeling, a current flow through the first diode (D1) is possible. There is a snubber network with a snubber capacitor, a second and third diode and an auxiliary inductance, a series circuit including the snubber capacitor, the third diode and the auxiliary inductance being coupled in parallel with the inductance.

Abstract: A short-arc lamp (1) with a discharge vessel (2) which contains an anode (3) and cathode (4) which are opposite one another. The filling medium contains inert gases and/or metal vapors, and the anode comprises a body having a front section (11), a substantially cylindrical body (12) and a rear face (13). Provided in the region of the front half of the cylindrical body is a projection (20) whose radial length (X) projects at least 0.5 mm beyond the cylindrical body (12).

Abstract: Piezoelectric transformer with an input and an output region. Input and/or output regions are sub-divided into sections (13-16) of inverse polarization. Depending on the number of sections, a multiplication of the transformation ratio is achieved without increasing the field strength in the piezoelectric material.

Abstract: The invention relates to a circuit arrangement for operating electric lamps, having a free-running half-bridge inverter (Q1, Q2). An auxiliary transistor (T1, T2) is in each case connected into the control circuits of the half-bridge inverter transistors (Q1, Q2), so that the emitter impedance of each half-bridge inverter transistor (Q1, Q2) is formed by a parallel circuit which consists of at least one resistor (R5) or (R7) and the control path, arranged in parallel therewith, of the corresponding auxiliary transistor (T1) or (T2). The control inputs of the two auxiliary transistors (T1, T2) are, furthermore, connected to the output of a common control circuit (IC).