LED luminaire driving circuit and method

Patent metadata

Field	Value
Publication number	US-9839082-B2
Application number	US-201615333223-A
Country	US
Kind code	B2
Filing date	Oct 25, 2016
Priority date	Oct 2, 2013
Publication date	Dec 5, 2017
Grant date	Dec 5, 2017

Abstract

A flyback converter is provided with a first output associated with a first secondary winding, a primary side controller arranged to maintain the first output at a predetermined voltage level and a second output associated with a second secondary windings; an LED controller. A first secondary electronically controlled switch is responsive to the LED controller; a first LED luminaire arranged to provide a first illumination responsive to a power signal on the second output when the first secondary electronically controlled switch is in a closed state and not provide the first illumination when the first secondary electronically controlled switch is in the open state, wherein the turns ratio of the first secondary winding and the second secondary winding is such that power is delivered to the first output via the first unidirectional electronic valve only when the first secondary electronically controlled switch is switched to the open state.

First claim

The invention claimed is:

1. A circuit for driving at least one light emitting diode (LED) luminaire, said circuit comprising:
a primary side controller;
a flyback converter comprising a transformer having a primary winding and a plurality of secondary windings each magnetically coupled to said primary winding, and a primary electronically controlled switch, said primary electronically controlled switch arranged to alternately open and close responsive to said primary side controller, said open and closed state arranged to adjust a current flowing through said primary winding;
a first output associated with a first of said plurality of secondary windings, said primary side controller arranged to alternately open and close said primary electronically controlled switch so as to maintain said first output at a predetermined voltage level;
a first unidirectional electronic valve arranged between said first secondary winding and said first output;
a second output associated with a second of said plurality of secondary windings;
an LED controller;
a first secondary electronically controlled switch arranged to be alternately in a open state and a closed state responsive to said LED controller;
a first LED luminaire arranged in cooperation with said first secondary electronically controlled switch to provide a first illumination responsive to a power signal on said second output when said first secondary electronically controlled switch is in said closed state and not provide the first illumination when said first secondary electronically controlled switch is in said open state; and
a second unidirectional electronic valve arranged between said second of said plurality of secondary windings and said first LED luminaire,
wherein the turns ratio of said first secondary winding and said second secondary winding is such that power is delivered to said first output via said first unidirectional electronic valve only when said first secondary electronically controlled switch is switched to said open state.

2. The circuit of claim 1 , wherein said second output power signal exhibits an active portion which provides sufficient voltage to provide the first illumination and an inactive portion which does not provide sufficient voltage to provide the first illumination, and
wherein said LED controller is arranged to synchronize said alternate closing and opening of said first secondary electronically controlled switch with one of falling edge modulation and leading edge modulation such that said first secondary electronically controlled switch is switched to said closed state, from said second state, in synchronization with said second output power signal inactive portion.

3. The circuit of claim 2 , further comprising:
a second secondary electronically controlled switch arranged to be alternately in an open state and a closed state responsive to said LED controller;
a second LED luminaire coupled in parallel with said first LED luminaire, said second LED luminaire arranged in cooperation with said second secondary electronically controlled switch to provide a second illumination responsive to the power signal from said second output when said second secondary electronically controlled switch is in said closed state and not provide the second illumination when said second secondary electronically controlled switch is in said open state; and
a third unidirectional electronic value arranged between said second output and said second LED luminaire,
wherein said LED controller is arranged to synchronize said alternate opening and closing of said second secondary electronically controlled switch with the one of the falling edge modulation and leading edge modulation such that said second secondary electronically controlled switch is switched to one of said closed and open states in synchronization with said second output power signal inactive portion, and
wherein the turns ratio of said first secondary winding and said second secondary winding are such that power is delivered to said first output via said first unidirectional electronic valve only when said first and second secondary electronically controlled switches are both switched to said open states.

4. An LED luminaire driving method, the method comprising:
switching a primary side electronically controlled switch so as to produce a first output power signal, associated with a first of a plurality of secondary windings of a transformer, each of the plurality of secondary windings of the transformer magnetically coupled to a primary winding of the transformer;
adjusting the duty cycle of said switching to maintain the first output power signal at a predetermined level;
alternately opening and closing a first secondary electronically controlled switch;
responsive to said closed state of the first secondary electronically controlled switch and further responsive to a second power signal on a second output associated with a second of the plurality of secondary windings, enabling a first LED luminaire to provide a first illumination; and
responsive to said open state of the first secondary electronically controlled switch, disabling the first LED luminaire so as not to provide the first illumination,
wherein the turns ratio of the first secondary winding and the second secondary winding is such that power is delivered to the first output from the transformer only when said first illumination is not enabled.

5. The method according to claim 4 , wherein the second power signal on the second output exhibits an active portion which provides sufficient voltage to provide the first illumination and an inactive portion which does not provide sufficient voltage to provide the first illumination, the method further comprising synchronizing said enabling and disabling of the first LED luminaire with one of falling edge modulation and leading edge modulation such that said switching of the first secondary electronically controlled switch to one of said closed and open states is in synchronization with the second output power signal inactive portion.

6. The method of claim 5 , further comprising:
alternately opening and closing a second secondary electronically controlled switch;
responsive to said closed state of the second secondary electronically controlled switch and further responsive to the second power signal, enabling a second LED luminaire, coupled in parallel to the first LED luminaire, to provide a second illumination;
responsive to said open state of the second secondary electronically controlled switch, disabling the second LED luminaire so as not to provide the second illumination; and
synchronizing said enabling and disabling of the second LED luminaire with said inactive portion of said second output power signal, said synchronizing comprising one of falling edge modulation and leading edge modulation such that said switching of said second secondary electronically controlled switch to one of said closed and open states is in synchronization with said second output power signal inactive portion,
wherein the turns ratio of the first secondary winding and the second secondary winding is such that power is delivered to the first output from the transformer only when neither of said first illumination and said second illumination are enabled.

Assignees

• Microsemi Corp

Inventors

• Jin Xiaoping

Classifications

• H05B45/382

  with galvanic isolation between input and output · CPC title

• H05B45/39

  Circuits containing inverter bridges · CPC title

• H05B33/0827

  Electricity · mapped topic

• H05B33/0815 Primary

  Electricity · mapped topic

• H05B33/0809

  Electricity · mapped topic