Modular lighting application
A modular system includes an LED driver and an LED light engine. The driver includes a switched mode power converter and a first control unit to control a switch of the converter, thereby controlling the supply current to an LED assembly of the light engine. The assembly includes LEDs and one or more switches arranged in series or in parallel with one or more of the LEDs. The light engine also includes a second control unit controlling the one or more switches of the LED assembly so as to control current through the LEDs. The first control unit controls amplitude of the supply current. The second control unit controls duty cycle of the LED current through the LEDs. The first and second control units are configured to synchronize a switching operation of the switched mode power converter with a switching operation of the switches of the light engine.
1. A modular system comprising a first component comprising an LED driver, a second component comprising a light engine and a third component comprising an interface module,
the light engine comprising a plurality of LEDs or LED groups;
the interface module comprising:
an input terminal for connecting to an output terminal of the LED driver;
an output terminal for connecting to an input terminal of the light engine;
a switch assembly comprising one or more switches for controlling a supply current of the LED driver, the supply current being received via the input terminal and provided to the light engine via the output terminal;
a control unit having an input terminal for receiving a set point representing a desired illumination characteristic of the light engine, the control unit further having a processing unit for processing the set point and determining control signals for the switch assembly,
the LED driver comprising:
a switched mode power converter configured to output the supply current;
an LED driver control unit configured to control a switch of the switched mode power converter, thereby controlling the supply current;
wherein the control unit and the LED driver control unit are configured to co-operate and control the supply current and the supply of the supply current to the light engine in accordance with the desired illumination characteristic, and wherein the control unit and the LED driver control unit are configured to synchronize a switching operation of the switch of the switched mode power converter with a switching operation of the one or more switches of the switch assembly of the interface module,
wherein the LED driver control unit is configured to control the LED driver to provide a current pulse during a predetermined period to synchronize the switching operation of the switch of the switched mode power converter with the switching operation of the one or more switches of the switch assembly of the interface module,
wherein the current pulse comprises multiple micropulses configured to transmit information, and
wherein a duration of the multiple micropulses is a fraction of a period of the predetermined period.
2. The modular system according to claim 1 , wherein the control unit and the LED driver control unit are configured to control the LED assembly to generate the desired illumination characteristic by controlling the switch and the one or more switches within a predetermined modulation time window.
3. The modular system according to claim 2 , wherein the control unit is configured to:
receive, at an input terminal of the control unit, an input signal representing the desired illumination characteristic;
determine, based on the desired illumination characteristic, a current amplitude modulation scheme, optionally a duty cycle modulation scheme and a time-division scheme;
provide an output signal representative of the current amplitude modulation scheme and optionally the duty cycle modulation scheme to the LED driver control unit; wherein the LED driver control unit is configured to apply the current amplitude modulation scheme and optionally the duty cycle modulation scheme within the modulation time window and wherein the control unit is configured to apply the time-division scheme within the modulation time window, in order to generate the desired illumination characteristic.
4. The modular system according to claim 3 , wherein the current amplitude modulation scheme represents an amplitude of the supply current as a function of time within the modulation time window.
5. The modular system according to claim 3 , wherein the duty cycle modulation scheme represents switching operations for the switch of the switched mode power supply as a function of time within the modulation time window.
6. The modular system according to claim 3 , wherein the time-division scheme represents a subdivision of the modulation time window into a plurality of sub-windows, whereby each of the plurality of LEDs or LED groups is provided with the supply current during only one sub-window of the plurality of sub-windows.
7. The modular system according to claim 6 , wherein the subdivision of the modulation time window into the plurality of sub-windows is based on a desired color of the illumination characteristic.
8. The modular system according to claim 6 , wherein the sub-windows have the same duration.
9. The modular system according to claim 1 , wherein the current pulse is indicative for a start of a modulation time window.
10. The modular system according to claim 1 , wherein the interface module is configured to detect a timing of the current pulse.
11. The modular system according to claim 9 , wherein the current pulse comprises one or more micropulses.
12. The modular system according to claim 11 , wherein the interface module is configured to identify a start of a sub-window of the modulation time window based on the micropulses.
13. The modular system according to claim 1 , wherein the control unit and the LED driver control unit are configured to synchronize a switching operation of the switch of the switched mode power converter with a switching operation of the one or more switches of the switch assembly by exchanging a synchronization signal.
14. The modular system according to claim 1 , further comprising a serial communication link for connecting a first control unit to a second control unit.
15. The modular system accordingly to claim 1 , wherein each micropulse of the multiple micropulses is a sub-window for communication of the information from the LED driver control unit to the interface module.
16. A modular system comprising a first component comprising an LED driver, a second component comprising a light engine and a third component comprising an interface module,
the light engine comprising a plurality of LEDs or LED groups;
the interface module comprising:
an input terminal for connecting to an output terminal of the LED driver;
an output terminal for connecting to an input terminal of the light engine;
a switch assembly comprising one or more switches for controlling a supply current of the LED driver, the supply current being received via the input terminal and provided to the light engine via the output terminal;
a control unit having an input terminal for receiving a set point representing a desired illumination characteristic of the light engine, the control unit further having a processing unit for processing the set point and determining control signals for the switch assembly,
the LED driver comprising:
a switched mode power converter configured to output the supply current;
an LED driver control unit configured to control a switch of the switched mode power converter, thereby controlling the supply current;
wherein the control unit and the LED driver control unit are configured to co-operate and control the supply current and the supply of the supply current to the light engine in accordance with the desired illumination characteristic, and wherein the control unit and the LED driver control unit are configured to synchronize a switching operation of the switch of the switched mode power converter with a switching operation of the one or more switches of the switch assembly of the interface module,
wherein the LED driver control unit is configured to control the LED driver to provide a current pulse during a predetermined period to synchronize the switching operation of the switch of the switched mode power converter with the switching operation of the one or more switches of the switch assembly of the interface module,
wherein the current pulse comprises multiple micropulses configured to transmit information,
wherein a duration of the multiple micropulses is a fraction of a period of the predetermined period, and
wherein the interface module is configured to detect the current pulse based on a measurement of the supply current or a measurement of a forward voltage across the LED or LED group to which the supply current is supplied.
17. The modular system accordingly to claim 16 , wherein each micropulse of the multiple micropulses is a sub-window for communication of the information from the LED driver control unit to the interface module.