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;
wherein the driver circuit further comprises current sensing means configured to determine a feedback signal indicative of the level of the current through the transistor; 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 via a gate control signal applied to the gate of the transistor so that it is traversed by a controlled current, thereby providing a controlled load to the mains voltage; and
control the level of the current through the transistor, when in the second mode, by determining the gate control signal based on the feedback signal.
1 Assignment
0 Petitions
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.
16 Citations
26 Claims
-
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;
wherein the driver circuit further comprises current sensing means configured to determine a feedback signal indicative of the level of the current through the transistor; 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 via a gate control signal applied to the gate of the transistor so that it is traversed by a controlled current, thereby providing a controlled load to the mains voltage; andcontrol the level of the current through the transistor, when in the second mode, by determining the gate control signal based on the feedback signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
- and a power converter network;
-
10. 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 controlled via a gate control signal applied to the gate of the transistor so that it 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;current sensing means configured to determine a feedback signal indicative of the level of the current through the transistor; and a 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; andcontrol the level of the current through the transistor, when in the second mode, by determining the gate control signal based on the feedback signal. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
- wherein in the first mode, the transistor alternates between an on-state and an off-state at a commutation cycle rate;
-
22. 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 controlled via a gate control signal applied to the gate of the transistor so that it 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;current sensing means configured to determine a feedback signal indicative of the level of the current through the transistor; and a 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;
wherein the control unit is further configured to control the level of the current through the transistor, when in the second mode, by determining the gate control signal based on the feedback signal; anda SSL device configured to provide light at an illumination level in accordance to the drive voltage and drive current. - View Dependent Claims (23, 24, 25, 26)
-
Specification