Emergency lighting systems including bidirectional booster/charger circuits

• US 8,823,272 B2
• Filed: 05/08/2012
• Issued: 09/02/2014
• Est. Priority Date: 12/12/2011
• Status: Active Grant

• Current Assignee: IDEAL Industries Lighting, LLC (Ideal Industries Incorporated)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Trainor, John J., McBryde, James A., Powers, Randall L., Chobot, Joseph P.
• Primary Examiner(s): Tan, Vibol
• Application Number:
  US13/466,324
• Publication Number:
  US 20130147376A1
• Time in Patent Office: 847 Days
• Field of Search: 315/200.R, 315/247, 315/307, 315/362, 315/209.R, 315/150, 315/86, 315/160, 315/161, 315/130, 315/131, 315/33, 363/101, 363/17, 363/37, 363/98
• US Class Current: 315/200.R
• CPC Class Codes: F21S 9/022 Emergency lighting devices
• CPC Class Codes: G01R 31/40 Testing power supplies testing photovoltaic devices H02S50/10
• CPC Class Codes: G01R 31/44 Testing lamps
• CPC Class Codes: H02J 9/065 for lighting purposes
• CPC Class Codes: H05B 45/10 Controlling the intensity of the light
• CPC Class Codes: H05B 45/12 using optical feedback
• CPC Class Codes: H05B 45/18 using temperature feedback
• CPC Class Codes: H05B 45/38 using boost topology
• CPC Class Codes: H05B 47/105 in response to determined parameters
• CPC Class Codes: H05B 47/17 Operational modes, e.g. switching from manual to automatic mode or prohibiting specific operations
• CPC Class Codes: H05B 47/19 via wireless transmission
• CPC Class Codes: H05B 47/195 the transmission using visible or infrared light

Abstract

An emergency lighting module for providing emergency power to a solid state luminaire is provided. The emergency lighting module includes a control circuit configured to detect a line voltage, a first input configured to receive an input voltage from the solid state luminaire, and a bidirectional booster/charger circuit coupled to the microcontroller and configured to charge a battery using the input voltage. The bidirectional booster/charger circuit is further configured to provide an output voltage. The emergency lighting module is configured to provide the output voltage to the solid state luminaire in response to a reduction of the line voltage.

Claims

1. An emergency lighting module for providing emergency power to a solid state luminaire, the emergency lighting module comprising:

a detector configured to detect a line voltage;

a first input configured to receive an input voltage from the solid state luminaire; and

a bidirectional booster/charger circuit configured to charge a battery using the input voltage from the solid state luminaire as a power source and to provide an output voltage;

wherein the emergency lighting module is configured to supply the output voltage to the solid state luminaire in response to a reduction of the line voltage.

2. The emergency lighting module of claim 1, wherein the bidirectional booster/charger circuit comprises:

a first input/output terminal;

a first input/output capacitor coupled to the first input/output terminal;

a second input/output terminal;

a second input/output capacitor coupled to the second input/output terminal;

a first switch coupled to the first input/output terminal and to a first node;

a second switch coupled to the first node and to ground; and

an inductor coupled between the first node and the second input/output terminal;

wherein the first switch is controlled by a first control signal and the second switch is controlled by a second control signal.

3. The emergency lighting module of claim 2, wherein the first and second switches comprise MOSFET switches.

4. The emergency lighting module of claim 2, wherein the first input/output terminal is configured to receive an input DC voltage from the solid state luminaire and to supply an output DC voltage to the solid state luminaire;

and

wherein the second input/output terminal is configured to supply a charge voltage to the battery and to receive a battery voltage from the battery.

5. The emergency lighting module of claim 1, wherein the emergency lighting module is configured to ramp the output DC voltage up from an initial voltage level to a target voltage level in response to detecting reduction of the AC line signal.

6. The emergency lighting module of claim 5, wherein the initial voltage level is zero volts.

7. The emergency lighting module of claim 5, wherein the emergency lighting module is configured to ramp the output DC voltage down from the target voltage level to zero volts in response to detecting restoration of the AC line signal.

8. The emergency lighting module of claim 1, further comprising a control circuit coupled to the detector and the bidirectional booster/charger, wherein the control circuit it configured to receive a signal from the detector indicative of a status of the line voltage.

9. The emergency lighting module of claim 8, wherein the bidirectional booster/charger circuit is configured to charge the battery in response to a first control signal from the control circuit.

10. The emergency lighting module of claim 8, wherein the bidirectional booster/charger circuit is configured to generate the output voltage in response to a second control signal from the control circuit.

11. The emergency lighting module of claim 8, wherein the line voltage comprises an AC line voltage, the input voltage comprises a DC input voltage, and the output voltage comprises a DC output voltage.

12. The emergency lighting module of claim 8, wherein the detector comprises a rectifier configured to rectify the AC line voltage to generate a rectified AC voltage signal, and a comparator coupled to the rectifier and configured to compare the rectified AC voltage signal to a reference voltage to generate the signal indicative of the line voltage.

13. A bidirectional booster/charger circuit, comprising:

a first input/output terminal;

a first input/output capacitor coupled to the first input/output terminal;

a second input/output terminal;

a second input/output capacitor coupled to the first input/output terminal;

a first switch coupled to the first input/output terminal and to a first node;

a second switch coupled to the first node and to ground; and

an inductor coupled between the first node and the second input/output terminal;

wherein the first switch is controlled by a first control signal and the second switch is controlled by a second control signal;

wherein the first input/output terminal is configured to receive an input DC voltage from an external circuit and to supply an output DC voltage to the external circuit; and

wherein the second input/output terminal is configured to supply a charge voltage to a battery and to receive a battery voltage from the battery.

14. The bidirectional booster/charger circuit of claim 13, wherein the first input/output terminal is configured to receive an input DC voltage from a solid state luminaire and to supply an output DC voltage to the solid state luminaire;

and

wherein the second input/output terminal is configured to supply a charge voltage to a battery and to receive a battery voltage from the battery.

15. The bidirectional booster/charger circuit of claim 13, further comprising a control circuit coupled to the bidirectional booster/charger, wherein the control circuit it configured to receive a signal indicative of a status of a line voltage.

16. The bidirectional booster/charger circuit of claim 15, wherein the bidirectional booster/charger circuit is configured to charge the battery in response to a first control signal from the control circuit.

17. The bidirectional booster/charger circuit of claim 15, wherein the bidirectional booster/charger circuit is configured to generate an output voltage in response to a second control signal from the control circuit.

18. A bidirectional booster/charger circuit, comprising:

a controller configured to generate a first control signal and a second control signal;

a first input/output terminal;

a second input/output terminal;

a first switch coupled to the first input/output terminal and to a first node wherein the first switch is controlled by the first control signal;

a second switch coupled to the first node and to ground, wherein the second switch is controlled by the second control signal; and

an inductor coupled between the first node and the second input/output terminal;

wherein the controller is configured to selectively activate the first and second control signals to cause the bidirectional booster/charger circuit to selectively operate in a charging mode in which the bidirectional booster/charger circuit outputs a first voltage to the second input/output terminal in response to a supply voltage applied at the first input/output terminal or to selectively operate in a discharging mode in which the bidirectional booster/charger circuit outputs a second voltage to the first input/output terminal in response to a battery voltage applied at the second input/output terminal.

19. The bidirectional booster/charger circuit of claim 18, wherein the controller is configured to cause the bidirectional booster/charger circuit to operate in the discharging mode in response to detection of a loss of an AC line signal.

20. The bidirectional booster/charger circuit of claim 18, wherein the controller is configured to cause the bidirectional booster/charger circuit to operate in the charging mode in response to detection of a restoration of an AC line signal.