U.S. Philips Corporation

Klaus B Lohn

Dieter Leers

Martin Ossmann

Hans G Ganser

Pieter Postma

Horst Dannert

Bernd Hofmann

Bernd Rausenberger

Johannes Martinus De Regt

G&uuml;nther Hans Derra

Hubertus C M Van Den Nieuwenhuizen

Ulrich Boke

A short-arc discharge lamp ( ) is provided with a translucent lamp vessel ( ) which is closed in a gas-tight manner and which is provided with an ionizable fill. A first and a second electrode ( ) are arranged in the lamp vessel ( ) which are each connected to its own current conductor ( ) which extends to outside the lamp vessel. A starting antenna ( ) is arranged near to the lamp vessel, which antenna is connected to a further current conductor ( ). The starting antenna comprises an antenna container ( ) and a further electrode ( ) which antenna container ( ) is closed in a gas-tight manner and contains an ionizable fill, the further electrode ( ) being connected to the further current conductor ( ). This makes it possible to realize a shorter reignition time by means of a higher reignition voltage on the starting antenna while spark-over from the starting antenna ( ) to the lamp vessel ( ) is avoided.

Short-arc discharge lamp with a starting antenna

The discharge lamp comprises a piezotransformer and at least one of the lamp electrodes comprises a secondary side of the piezotransformer. Since the piezotransformer functions as a lamp electrode, as a ballast choke and as a transformer, the discharge lamp can be operated by means of a relatively simple and cheap ballast circuit.

Discharge lamp

An incandescent lamp with a low voltage burner (BM) and integrated voltage conversion means (VCM) having switching elements (Q1, Q2) driven by a separate control circuit (CC) comprising an integrated circuit (IC). The voltage conversion means are suitable for operation at a high temperature and causes only limited amounts of EMI.

Incandescent lamp with continuous high-frequency oscillations

A circuit for operating a discharge lamp having circut input terminals for connection to a supply voltage source and an inverter coupled to the circuit input terminals for generating an AC voltage at a frequency f from a supply voltage supplied by the supply voltage source. A piezotransformer has transformer input terminals coupled to the inverter output terminals. Terminals for lamp connection are coupled to the inverter output terminals and is provided for detecting whether the lamp has ignited. A protective device is coupled between the output terminals of the inverter and the transformer output terminals so that the inverter is effectively protected against damage due to ignition pulses generated by the piezotransformer.

Discharge lamp operating circuit using piezoelectric transformer and

A circuit arrangement for operating a lamp has circuit input terminals for connection to a supply voltage source. An inverter is coupled to the circuit input terminals for generating an AC voltage with a frequency f from a supply voltage supplied by the supply voltage source and includes inverter output terminals. A piezotransformer has input terminals coupled to the inverter output terminals. Terminals for lamp connection are coupled to the inverter output terminals. A detector detects whether the lamp has ignited. The transformer input terminals are connected to the inverter output terminals only by means of passive components and the inverter comprises means coupled to the detector for changing the frequency f in response to the ignition of the lamp. The circuit arrangement is simple and inexpensive and need not provide a device for switching the piezotransformer out of the circuit after ignition of the lamp.

Inventer-ballast using a piezoelectric transformer

A piezo-electric transformer comprising a piezo-electric body (PEB) including a driving region having input electrodes (1, 3) and at least one driven region having output electrodes (E11). These regions have opposite faces with at least one of the regions comprising a number of sections polarized in a direction perpendicular to the opposite faces and one pole of each section being connected to an opposite pole of another section by electrically conductive elements (2, 1', 2') in such a way that the sections form a series arrangement. These sections are in a very simple way effectively arranged in series, thereby increasing the input impedance of the piezo-electric transformer. Because the sections are polarized in opposing directions the electrically conductive elements can be of a very simple construction which do not require external conduction wires.

Piezo-electric transformer

A circuit arrangement for switching a current through the emitter-collector path of a bipolar transistor whose base receives a substantially square-wave switching signal from a switching generator via a series-arranged two-terminal network having inductive reactance. This signal switches the transistor alternately to the conducting and the non-conducting state. In such a circuit arrangement, a very short fall time of the current in the emitter-collector path of the transistor is achieved in a simple and economical way in that the value of the inductive reactance decreases when a current flowing through the two-terminal network increases.

Circuit arrangement for removing carriers in a transistor

An electronic transformer comprising first and second switching converters for converting the positive and negative half periods, respectively, of an input alternating voltage into high frequency voltages, which are rectified to produce an output alternating voltage at the input voltage frequency. The converters are constructed as fly-back converters with the choke coils as well as the output and input capacitors combined into elements common to the two respective high frequency fly-back converters. First and second backward diodes are connected parallel to each switching transistors of the two fly-back converters and each converter includes an auxiliary switching transistor switching at the input frequency to change over the converters from one half period to the other of the input AC voltage.

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Simmerath, Germany

Klaus B Lohn