U.S. Philips Corporation

Nxp B.v.

Koninklijke Philips Corporation N.v.

Silergy Corp.

Anton Cornelis Blom

Hans Halberstadt

Thomas Duerbaum

Frans Pansier

Alexander Pawellek

Juergen Stahl

Jens Goettle

Frans Slegers

Age Jochem Van Dalfsen

Markus Schmid

Arjan Van Den Berg

Dirk Wouter Johannes Groeneveld

Johann Kuebrich

Jie Chen

Wihelmus Hinderikus Maria Langeslag

A noise detection circuitfor a power supply, the noise detection circuitcomprising: an impedance elementconnected to a linefor carrying a power supply current having a noise signal component, the noise signal comprising a common mode noise signal and a differential mode noise signal; a filter elementcoupled to the impedance elementand configured to suppress the differential mode noise signal in the noise detection circuit; and an evaluation circuitcoupled to the impedance elementor the filter elementand arranged to sense the common mode noise signal and provide an output representative of the common mode noise signal.

Noise detection circuit

A noise filter circuit uses open loop signal processing to process the signal that causes the noise and generate a signal to be fed back into the system to cancel noise currents.

Noise filtering

A common mode noise sensor with a single amplification path is disclosed. The common mode noise sensor includes first and second terminals for receiving respective first and second signals from a power supply, an amplifier stage connected to the first and second terminals and having an output and a resistor network connected to the amplifier stage. The resistor network is arranged such that the output of the amplifier stage is configured to provide an output signal in which a differential mode noise in the first and second signals is suppressed in preference to a common mode noise in the first and second signals.

Noise sensor

The present invention relates to a noise sensor for an alternating or direct current power supply. The sensor comprises a noise sensing unit and a noise separator. The noise separator is configured to receive first, second and third input signals and provide a first output signal representative of the common mode noise and a second output signal representative of the differential mode noise. The noise sensing unit comprises a first capacitive element, a second capacitive element, a first resistive element and a second resistive element.

A control circuit is disclosed for lighting applications having a load and an AC leading-edge phase-cut dimmer comprising a phase-cutting switch, the circuit comprising: a detection circuit for detecting a deadlock state of the dimmer; and an activation circuit configured to, in response to the detection circuit detecting a deadlock state of the dimmer, supply a DC current to the dimmer to exit the deadlock state by activating the dimmer. A method of operating such a control circuit is also disclosed.

Control circuit for a phase-cut dimmer and a method of controlling a phase-cut dimmer

A circuit is disclosed for driving a plurality of LED strings from an AC supply and arranged to, in use, drive current through a series arrangement of a plurality N of the LED strings when the AC voltage is sufficient to drive the plurality N of the LED strings: the circuit comprising a first current source configured to be switchably connected to a one end of said series arrangement of N LED strings; a series combination of a second current source and a heat dissipater, wherein the series combination of the second current source and the heat dissipater is arranged in parallel with the first current source; and a current balancer for balancing the current through the first current source and the second current source. A driver for such a circuit is also disclosed.

Circuit for driving LEDs

An electronic switching device comprises a first bipolar junction transistor (BJT) () adapted to control the flow of current between a pair of switching terminals; a charge recovery circuit coupled to the base of the first BJT () and adapted to establish a supply voltage across a capacitor () by storing in the capacitor () charge carriers accumulated in the base of the first BJT () during application of a base drive current, the quantity of accumulated charge carriers depending on the base drive current; and a controllable current source () adapted to control the base drive current, thereby controlling the supply voltage.

Electronic switching device

A switched mode power supply includes an input for receiving an input signal voltage, a flyback converter circuit arrangement and an output for delivering a regulated output signal voltage. The switched mode power supply further includes a boost converter arranged to be operatively combined with the flyback converter, and functioning such that the combined converter operates in a boost mode when the input voltage is above a threshold value, and in a flyback mode when the input voltage is below the threshold value.

Switched mode power supply having a boost converter operatively combined with a flyback converter

An LLC power converter has an output voltage which is determined by a frequency controller controlling the frequency of an on and off switching of the switches ( ) of the converter. In order to stabilize the output voltage at varying output currents, a control circuit feeds back the variation of the total current (I) in the converter to the frequency controller ( ) for correcting the frequency of the on and off switching of the switches.

LLC converter includes a current variation detector for correcting a frequency adjusting control signal of an included difference detector

A half-bridge circuit which is operated as a double down-converter is equipped with a second inductor and power feedback capacitors and diodes. The power factor of the circuit is substantially improved thereby.

Circuit arrangement with improved power-factor for feeding a discharge lamp

A circuit arrangement for igniting and operating a discharge lamp is provided with input terminals for connecting a supply source and a commutator having output terminals for connecting a lamp to be operated, the commutator including at least two switches which are alternately in a conducting and a non-conducting state. The commutator is suitable for pulse width modulation (PWM) operation of the switches. The switches and an output terminal are connected to one another by coupled inductors for this purpose.

Commutator for a discharge lamp having mutually coupled inductors

In an ignition circuit for a high-pressure discharge lamp having a pulse generating circuit in which ignition pulses are generated by a voltage-dependent breakdown element and a pulse transformer, a bandpass circuit has been inserted between the secondary winding of the pulse transformer and the discharge lamp. The bandpass filter is tuned to the fundamental frequency or a harmonic of the pulses generated by the pulse generation circuit.

Discharge lamp ignition circuit having a bandpass filter connecting the

A circuit for operating a lamp includes supply input terminals for connection to a supply voltage source and a transformer provided with a primary winding L1 and a secondary winding L2. A first branch has terminals (N1,N2) for holding the lamp and connects a first end of the secondary winding L2 to a second end thereof. A second branch comprising a series circuit of a switching element (Q1) and the primary winding L1 interconnects the supply input terminals. A control circuit (SC1) is coupled to a control electrode of the switching element for generating a control signal for rendering the switching element conducting and non-conducting, and thus generating a first current in the primary winding L1 and a second current in the secondary winding L2. The second branch comprises a series arrangement of the primary winding, the switching element (Q1), and the terminals (N1,N2) for connection to the lamp. The total lamp current is controlled via the switching element which passes only a portion of the lamp current.

Lamp circuit arrangement for controlling current flow through switching

The invention relates to a circuit arrangement for igniting a high-pressure discharge lamp (L), provided with input terminals (C,D) for connection to a commutating supply source with a square-wave supply voltage; a pulse-generating circuit (IV) provided with a voltage-dependent breakdown element (3) and with a voltage-raising network (2) formed by a network of rectifiers and capacitors; a pulse transformer (1); and an electrical connection between a secondary winding (12) of the pulse transformer and lamp connection terminals (E,F). The voltage-raising network (2) is in addition provided with inductors means (21, 22). The result of this is that a strongly increased voltage is available across the breakdown element substantially instantaneously after each commutation of the commutating supply voltage.

High-pressure discharge lamp igniting circuit in which the

A circuit arrangement (II) for igniting a high-pressure discharge lamp provided with a pulse transformer, a switching device and a capacitive element for a periodic charge inversion via the transformer and the switching device. The circuit arrangement is also provided with a peak current limiting impedance to protect the switching device. A voltage limiting device is added to the transformer. By the provision of the voltage limiting device, the lamp ignition is to a high degree made to be independent of lamp connection line impedances.

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Eindhoven, Netherlands

Anton Cornelis Blom