Infineon Technologies Ag

Infineon Technologies Austria Ag

Antoine Fery

Martin Feldtkeller

Michael Herfurth

A method for use in a lamp ballast includes obtaining a measurement signal representative of a voltage at an output of a half-bridge circuit. The half-bridge circuit includes first and second semiconductor switching elements, a resonant circuit connected to the half-bridge circuit, and a snubber capacitance connected in parallel with one of the semiconductor switching elements. The method also includes providing a comparison signal by comparing the measurement signal with a reference value. The method further includes detecting one of a first type of non-zero-voltage switching operation and a second type of non-zero-voltage switching operation based on evaluations of the comparison signal, wherein the evaluations of the comparison signal occurs in each case before the first semiconductor element is switched on and in each case before the second semiconductor element is switched on.

Method for detection of non-zero-voltage switching operation of a ballast of fluorescent lamps, and ballast

A method detects a non-zero-voltage switching operation of a lamp ballast, the lamp ballast including a half-bridge circuit with a first and a second semiconductor switching element, a resonant circuit connected to the half-bridge circuit, and a snubber capacitance connected in parallel with one of the semiconductor switching elements. The method includes obtaining a voltage measurement signal representative of a voltage at an output of the half-bridge circuit. The method also includes providing a comparison signal representative of a comparison of the voltage measurement signal with a reference value. The method further includes evaluating the comparison signal in each case before the first semiconductor element is switched on and in each case before the second semiconductor element is switched on, and detecting one of a first and second non-zero-switching operations based on these evaluations.

A switch-mode converter. One embodiment provides an inductive energy storage element. A rectifier arrangement is coupled to the inductive energy storage element for providing an output voltage. A switching arrangement regulates the inductive energy storage element on the basis of a control signal. A controller arrangement is configured to generate the control signal on the basis of the output voltage. The controller arrangement has a discrete-time band rejection filter and a frequency measuring arrangement.

Switch-mode converter

A method and apparatus for providing electrical current to a lamp, detecting a power supply voltage outage, detecting a return of the power supply voltage, determining how long the power supply voltage outage lasted, and preheating the lamp responsive to determining that the power supply voltage outage lasted greater than a threshold amount of time.

Controlling a lamp ballast

The invention relates to a method for detection of non-zero-voltage switching operation of a lamp ballast, which has a half-bridge circuit with a first and a second semiconductor switching element, a resonant tuned circuit which is connected to one output of the half-bridge circuit, and a snubber capacitance, which is connected in parallel with one of the semiconductor switching elements. The method has the following method steps:

A drive circuit for at least one fluorescent lamp has a half-bridge circuit for production of a supply voltage a resonant tuned circuit coupled to the half-bridge circuit and to which the at least one fluorescent lamp can be connected, a diagnosis circuit with a resistance element coupled to the resonant tuned circuit, at least one current/voltage converter connected to the resistance element that produces at least one measurement voltage from a current flowing through the resistance element, and an evaluation circuit which is connected to the current/voltage converter and is supplied with the at least one measurement voltage and to a method for diagnosis of a fluorescent lamp.

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Munich, Germany

Antoine Fery