LIGHTING SYSTEM, ELECTRONIC DEVICE FOR A LIGHTING SYSTEM AND METHOD FOR OPERATING THE ELECTRONIC DEVICE
First Claim
1. An electronic device for a lighting system, wherein the lighting system comprises a TRIAC dimmer and is configured to receive a mains supply voltage and to provide a phase cut voltage to the electronic device, wherein the electronic device comprises:
- a control loop that is configured to control a duty cycle of a switched voltage converter that receives a rectified phase cut voltage as an input voltage and provides a drive current to a light emitting semiconductor device,the control loop comprises an error amplifier that is coupled to receive a sense voltage that is indicative to a current through the light emitting semiconductor device,the error amplifier being configured to provide a feedback signal to a pulse width modulation logic that is configured to control the duty cycle of the switched voltage converter so as to provide a constant drive current to the light emitting semiconductor device in response to the sense voltage andthe error amplifier being coupled to receive a reference voltage that is a function of the input voltage.
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Accused Products
Abstract
An electronic device for a lighting system, comprising a TRIAC dimmer configured to receive a mains supply voltage and provide a phase cut voltage to the electronic device and having a control loop configured to control a duty cycle of a switched voltage converter that receives the rectified input voltage and provides drive current to a light emitting semiconductor device. The control loop has an error amplifier that is coupled to receive a sense voltage that is indicative of a current through the light emitting semiconductor device, the error amplifier is configured to provide a feedback signal to a pulse width modulation logic configured to control the duty cycle of the switched voltage converter to provide a constant drive current to the light emitting semiconductor device in response to the sense voltage, the error amplifier being coupled to receive a reference voltage that is a function of the input voltage.
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Citations
12 Claims
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1. An electronic device for a lighting system, wherein the lighting system comprises a TRIAC dimmer and is configured to receive a mains supply voltage and to provide a phase cut voltage to the electronic device, wherein the electronic device comprises:
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a control loop that is configured to control a duty cycle of a switched voltage converter that receives a rectified phase cut voltage as an input voltage and provides a drive current to a light emitting semiconductor device, the control loop comprises an error amplifier that is coupled to receive a sense voltage that is indicative to a current through the light emitting semiconductor device, the error amplifier being configured to provide a feedback signal to a pulse width modulation logic that is configured to control the duty cycle of the switched voltage converter so as to provide a constant drive current to the light emitting semiconductor device in response to the sense voltage and the error amplifier being coupled to receive a reference voltage that is a function of the input voltage. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method for operating a an electronic device for a lighting system, wherein the lighting system comprises a TRIAC dimmer and is configured to receive a mains supply voltage and to provide a phase cut output voltage to the electronic device, the method comprising:
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receiving a phase cut voltage from the TRIAC dimmer; rectifying the phase cut voltage to provide a rectified input voltage; converting the input voltage with a switched voltage converter so as to provide a drive current to a light emitting semiconductor device; receiving a sense voltage that is indicative to a current through the light emitting semiconductor device at an error amplifier; coupling an output signal of the error amplifier as a feedback signal to a pulse width modulation logic that is a part of a control loop of the electronic device and that is configured to control a duty cycle of the switched voltage converter so as to provide a constant drive current to the light emitting semiconductor device in response to the sense voltage; coupling a reference voltage that is a function of the input voltage to the error amplifier; and providing an updated feedback signal to the pulse width modulation logic to vary a duty cycle of the switched voltage converter so as to provide an updated constant drive current to the light emitting semiconductor device in response to the sense voltage and the reference voltage.
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12. A lighting system comprising a TRIAC dimmer that is configured to receive a mains supply voltage and to provide a phase cut voltage to an electronic device for providing a drive current to a light emitting semiconductor device, wherein the electronic device comprises:
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a control loop that is configured to control a duty cycle of a switched voltage converter that receives the rectified input voltage and provides a drive current to the light emitting semiconductor device; the control loop comprises an error amplifier that is coupled to receive a sense voltage that is indicative to the drive current through the light emitting semiconductor device; the error amplifier is configured to couple a feedback signal to a pulse width modulation logic that is configured to control the duty cycle of the switched voltage converter so as to provide a constant drive current to the light emitting semiconductor device in response to the sense voltage; and the error amplifier is coupled to receive a reference voltage that is a function of the input voltage provided to the electronic device.
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Specification