DUAL POWER SMPS FOR A MODULAR LIGHTING SYSTEM

• US 20140368118A1
• Filed: 08/28/2014
• Published: 12/18/2014
• Est. Priority Date: 06/30/2011
• Status: Active Grant

• Current Assignee: Schneider Electric Industries SAS (Schneider Electric SE)
• Original Assignee: Schneider Electric Industries SAS (Schneider Electric SE)
• Inventors: Sarkar, Rupan, Bhardwaj, Dhruv
• Granted Patent: US 9,510,405 B2
• Time in Patent Office: Days
• US Class Current: 315/175
• CPC Class Codes: H05B 45/3725 Switched mode power supply [SMPS]

Abstract

Methods and systems described herein provide efficient lighting where electric grid systems are unreliable. One as-peel includes a light assembly that includes an input to receive power from a power source, a controllable power supply having a control input, a power input coupled to the first input, and an output to provide a voltage level controllable based on a control signal received at the control input, a light circuit coupled to the output of the controllable power supply and configured to provide output light in response to the output voltage, a feedback circuit configured to detect a current to a battery and a voltage across the battery and having an output coupled to the control input of the controllable power supply to provide the control signal to the controllable power supply based on at least one of the current to the battery input and the voltage across the battery.

Claims

1. A light assembly comprising;

a first input to receive power from a power source;

a controllable power supply having a control input, a power input coupled to the first input, and an output to provide an output voltage having a voltage level controllable based on a control signal received at the control input;

a battery input coupled to the output of the controllable power supply, and configured to couple to a battery;

a light circuit coupled to the output of the controllable power supply and configured to provide output light in response to the output voltage; and

a feedback circuit configured to detect a current to the battery and a voltage across the battery and having an output coupled to the control input of the controllable power supply to provide the control signal to the controllable power supply based on at least one of the current to the battery input and the voltage across the battery.

2. The light assembly of claim 1, wherein the controllable power supply further comprises a PWM controller coupled to the power input, configured to generate a pulse width modulated signal having a duty cycle.

3. The light assembly of claim 2, wherein the PWM controller is configured to decrease the duty cycle of the pulse width modulated signal based on the control signal having a first state indicating that at least one of the current to the battery input and the voltage across the battery is above a threshold.

4. The light assembly of claim 2, wherein the PWM controller is configured to increase the duty cycle of the output voltage based on the control signal having a second state different from the first state.

5. The light assembly of claim 1, wherein the controllable power supply further comprises a transformer, configured to receive power from the power input.

6. The light assembly of claim 1, wherein the first input is configured to receive power from an AC power source.

7. The light assembly of claim 1, further comprising a second input configured to receive power from a solar power source.

8. The light assembly of claim 7, further comprising:

a DC-DC converter having a converter control input, a power input coupled to the second input, and a converter output to provide a converter output voltage having a converter voltage level controllable based on a converter control signal received at the converter control input; and

a converter feedback circuit configured to detect a current to the battery and a voltage across the battery and having an output coupled to the converter control input of the DC-DC converter to provide the converter control signal to the DC-DC converter based on at least one of the current to the battery input and the voltage across the battery,

wherein the light circuit is coupled the converter output and configured to provide output light in response to the converter output voltage.

9. A method of controlling operation of a light assembly comprising:

receiving power from a power source;

generating a DC voltage derived from the received power, the DC voltage having a voltage level;

applying the DC voltage to a light circuit;

applying the DC voltage to the battery;

detecting a current to the battery;

detecting a voltage across the battery; and

controlling the voltage level based on at least one of the current to the battery and the voltage across the battery.

10. The method of claim 9, wherein controlling the voltage level further comprises generating a pulse width modulated signal having a duty cycle.

11. The method of claim 10, wherein controlling the voltage level further comprises decreasing the duty cycle of the pulse width modulated signal if at least one of the current to the battery and the voltage across the battery is above a threshold.

12. The method of claim 10, wherein controlling the voltage level further comprises increasing the duty cycle of the pulse width modulated signal until the current to the battery has reached a threshold or the voltage across the battery has reached a threshold.

13. The method of claim 9, wherein generating a DC voltage further comprises using a transformer to step down a voltage derived from the received power.

14. The method of claim 9, wherein receiving power from a power source further comprises receiving power from at least one of an AC power source and a solar power source.

15. The method of claim 9, further comprising providing power to the light circuit from the battery.

16. A light assembly comprising:

at least one input to receive power from a power source;

a controllable power supply having a control input, a power input coupled to the at least one input, and an output;

a battery input coupled to the output of the controllable power supply;

a light circuit coupled to the output of the controllable power supply and configured to provide output light; and

means for controlling the power supply to provide a regulated voltage to the light circuit and regulated charging current and charging voltage to a battery coupled to the battery input.

17. The light assembly of claim 16, wherein the at least one input includes a first input configured to couple to an AC power source and a second input configured to couple to a solar power source.

18. The light assembly of claim 16, wherein the controllable power supply is configured to provide output DC power to the battery input and to the light circuit.

19. The light assembly of claim 16, further comprising means for detecting loss of AC power at the at least one input and for providing power to the light circuit from the battery.

20. The light assembly of claim 16, wherein the means for controlling includes means for charging the battery in a first mode supplying substantially constant current to the battery, and means for charging the battery in a second mode supplying a substantially constant voltage across the battery.