Solid State Lightening Driver with Mixed Control of Power Switch
First Claim
1. A control unit for a driver circuit which is configured to drive a solid state lightening, referred to as SSL device, subject to an input voltage derived from a mains voltage using a phase-cut dimmer, wherein the driver circuit comprises a transistor operable in a first mode and in a second mode;
- and a power converter network; and
wherein the control unit is configured tocontrol the transistor to selectively operate in the first and second mode;
wherein in the first mode, the transistor alternates between an on-state and an off-state at a commutation cycle rate, thereby providing a switched-mode power converter in conjunction with the power converter network;
wherein in the second mode, the transistor is controlled so that it is traversed by a controlled current, thereby providing a controlled load to the mains voltage.
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Accused Products
Abstract
In order to control of dimming of solid state lighting devices (SSL) a driver circuit drives the SSL subject to an input voltage using a phase-cut dimmer. The driver circuit comprises a transistor operable in two modes, either alternating between on/off states or continuously controlling a current through the transistor. A power converter network provides a switched-mode power converter in conjunction with the transistor when operated in the first mode generating a drive voltage for the SSL. The control unit controls the transistor to selectively operate in one of the two modes; to control the transistor to determine that the input voltage exceeds an input voltage threshold; and to control a drive current through the SSL based on a measurement of a phase-cut angle thereby controlling an illumination level of the SSL device.
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Citations
32 Claims
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1. A control unit for a driver circuit which is configured to drive a solid state lightening, referred to as SSL device, subject to an input voltage derived from a mains voltage using a phase-cut dimmer, wherein the driver circuit comprises a transistor operable in a first mode and in a second mode;
- and a power converter network; and
wherein the control unit is configured tocontrol the transistor to selectively operate in the first and second mode;
wherein in the first mode, the transistor alternates between an on-state and an off-state at a commutation cycle rate, thereby providing a switched-mode power converter in conjunction with the power converter network;
wherein in the second mode, the transistor is controlled so that it is traversed by a controlled current, thereby providing a controlled load to the mains voltage. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
- and a power converter network; and
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11. A driver circuit for driving a solid state lightening, referred to as SSL, device, subject to an input voltage derived from a mains voltage using a phase-cut dimmer, the driver circuit comprising
a transistor operable in a first mode and in a second mode; - wherein in the first mode, the transistor alternates between an on-state and an off-state at a commutation cycle rate;
wherein in the second mode, the transistor is traversed by a current at a smoothly controllable level;a power converter network configured to provide a switched-mode power converter in conjunction with the transistor when operated in the first mode;
wherein the power converter generates a drive voltage for the SSL device from the input voltage; anda control unit configured to control the transistor to selectively operate in the first and second mode;
wherein in the first mode, the transistor alternates between an on-state and an off-state at a commutation cycle rate, thereby providing a switched-mode power converter in conjunction with the power converter network;
wherein in the second mode, the transistor is controlled so that it is traversed by a controlled current, thereby providing a controlled load to the mains voltage. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
- wherein in the first mode, the transistor alternates between an on-state and an off-state at a commutation cycle rate;
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24. A light bulb assembly comprising
an electrical connection module configured to electrically connect to a mains voltage submitted to a phase-cut dimmer, thereby providing an input voltage; -
a driver circuit configured to provide a drive voltage and a drive current in accordance to a setting of the phase-cut dimmer, based on the input voltage the driver circuit comprising a transistor operable in a first mode and in a second mode;
wherein in the first mode, the transistor alternates between an on-state and an off-state at a commutation cycle rate;
wherein in the second mode, the transistor is traversed by a current at a smoothly controllable level;a power converter network configured to provide a switched-mode power converter in conjunction with the transistor when operated in the first mode;
wherein the power converter generates a drive voltage for the SSL device from the input voltage; anda control unit wherein the control unit is configured to control the transistor to selectively operate in the first and second mode;
wherein in the first mode, the transistor alternates between an on-state and an off-state at a commutation cycle rate, thereby providing a switched-mode power converter in conjunction with the power converter network;
wherein in the second mode, the transistor is controlled so that it is traversed by a controlled current, thereby providing a controlled load to the mains voltage; anda SSL device configured to provide light at an illumination level in accordance to the drive voltage and drive current. - View Dependent Claims (25, 26, 27, 28)
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29. A method to allow a reliable determination of the phase of a mains power submitted to a phase-cut dimmer, thereby reliably and efficiently controlling the illumination of a Solid State Lightening (SSL) lamp, wherein the method comprises the steps of:
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(1) providing a control unit, a driver circuit comprising a single power switch, and a SSL device, wherein the driver circuit is setting an illumination level of the SSL device in accordance to a setting of the phase-cut dimmer; (2) measuring a phase-cut-angle set by the phase-cut dimmer by using the single power switch; (3) translating measured setting of the phase-cut dimmer into a drive voltage and a drive current driving the SSL device by using the single switch for power conversion; and (4) sensing current through the power switch to determine a feedback signal indicative of the level of the current through the SSL in order to control the current. - View Dependent Claims (30, 31, 32)
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Specification