U.S. Philips Corporation

Koninklijke Philips Corporation N.v.

Martin Ossmann

Dieter Leers

Klaus B Lohn

Hans G Ganser

Pieter Postma

Christoph Loef

Christian Hattrup

Thomas Scheel

Horst Dannert

Bernd Rausenberger

Johannes Martinus De Regt

G&uuml;nther Hans Derra

Olaf Maertens

Hubertus C M Van Den Nieuwenhuizen

In order to determine the necessary operating parameters of a power supply system with a converter for supplying a resonant arrangement having a transformer, a system having a measuring device is proposed, which activates the converter so that with components of the power supply system initially unenergized a predetermined output voltage is generated, one or more parameters characteristic of the resonant arrangement being determined from the measurement of the resonant current appearing on the primary side of the transformer. In this, after a preferably brief excitation interval, the resonant frequency, the impedance of the resonant arrangement, the capacitance value of the resonant capacitance and the leakage inductance are determined on the basis of the current path.

Resonant switched mode power supply system

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

A circuit arrangement includes a self-oscillating oscillator circuit electrically connected with a series arrangement of a resistor arranged in series with a capacitor. The series arrangement determines the oscillation frequency of the oscillator circuit. The oscillator circuit serves to supply an oscillating supply voltage to an electronic device that exhibits a resonant frequency. A control signal output of the electronic device has a resistive coupling to the series arrangement. The control signal output serves to supply a control signal representative of the oscillation mode of the electronic device.

Circuit arrangement including a self-oscillator circuit

A circuit arrangement for supplying a lamp comprises a piezotransformer. During stationary operation the lamp is supplied via the piezotransformer. During ignition a DC-ignition voltage is generated over the secondary side of the piezotransformer acting as capacitor.

Circuit arrangement for igniting and operating a lamp having piezoelectric transformer

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

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.

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Aachen, Germany

Martin Ossmann