Light emitting diode (LED) driver having direct replacement capabilities

• US 9,419,537 B1
• Filed: 01/29/2015
• Issued: 08/16/2016
• Est. Priority Date: 01/29/2015
• Status: Active Grant

• Current Assignee: Technical Consumer Products, Inc. (Quality Light Source GmbH)
• Original Assignee: Technical Consumer Products, Inc. (Quality Light Source GmbH)
• Inventors: Haas, Daniel Albert, Chen, Timothy
• Primary Examiner(s): Le, Tung X
• Application Number:
  US14/608,335
• Publication Number:
  US 20160226393A1
• Time in Patent Office: 565 Days
• Field of Search: 315/200.R, 315/291, 315/294, 315/297, 315/307, 315/308, 315/312
• US Class Current: 1/1
• CPC Class Codes: H02M 7/217 using semiconductor devices only
• CPC Class Codes: H05B 45/50 responsive to malfunctions or undesirable behaviour of LEDs; responsive to LED life; Protective circuits
• CPC Class Codes: H05B 47/10 Controlling the light source
• CPC Class Codes: Y02B 20/30 Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Abstract

A driver circuit for powering a load is disclosed. The driver circuit includes an input for connection to a ballast, a rectifier, a switch, and a fault circuit. The rectifier converts AC power received from the input into DC power. The rectifier includes a rectifier input. The switch is electrically connected to the rectifier input. The switch is activated to create a short circuit at the rectifier inputs in response to receiving an activation signal. The fault circuit is electrically connected to the switch. The fault circuit generates the activation signal in response to detecting at least one of an over voltage, an over temperature, and an over current condition of the driver circuit.

Claims

1. A driver circuit for powering a load, comprising:

an input for connection to a ballast;

a rectifier for converting AC power received from the input into DC power, the rectifier including a rectifier input;

a switch electrically connected to the rectifier input, wherein the switch is activated to create a short circuit at the rectifier inputs in response to receiving an activation signal;

a fault circuit electrically connected to the switch, wherein the fault circuit generates the activation signal in response to detecting at least one of an over voltage, an over temperature, and an over current condition of the driver circuit; and

a charge pump circuit for providing substantially constant DC current to the fault circuit, the charge pump circuit including a first capacitor and a zener diode, wherein the first capacitor limits current to the zener diode and the zener diode limits a voltage provided to the fault circuit.

2. The driver circuit recited in claim 1, wherein the charge pump circuit includes a second capacitor and a diode, wherein the diode provides rectification and maintains a charge on the second capacitor.

3. The driver circuit recited in claim 1, wherein the switch is a silicon controlled rectifier (SCR).

4. The driver circuit recited in claim 1, wherein the switch is a metal-oxide-semiconductor field-effect transistor (MOSFET).

5. The driver circuit recited in claim 1, comprising a latching circuit for holding a fault condition detected by the fault circuit.

6. A driver circuit for powering a light emitting diode (LED) tube light, comprising:

an input for connection to a ballast;

a rectifier for converting AC power received from the input into DC power, the rectifier including a rectifier input;

a switch electrically connected to the rectifier input, wherein the switch is activated to create a short circuit at the rectifier inputs in response to receiving an activation signal;

a fault circuit electrically connected to the switch, wherein the fault circuit generates the activation signal in response to detecting at least one of an over voltage, an over temperature, and an over current condition of the driver circuit; and

a charge pump circuit for providing substantially constant DC current to the fault circuit, wherein the charge pump circuit includes a first capacitor and a zener diode, wherein the first capacitor limits current to the zener diode and the zener diode limits a voltage provided to the fault circuit.

7. The driver circuit recited in claim 6, wherein the charge pump circuit includes a second capacitor and a diode, wherein the diode provides rectification and maintains a charge on the second capacitor.

8. The driver circuit recited in claim 6, comprising a reference voltage circuit generating a reference voltage, wherein the reference voltage is used by the fault circuit as a reference value to determine the over voltage, the over temperature, and the over current condition of the driver circuit.

9. The driver circuit recited in claim 8, wherein the fault circuit compares a bus voltage of the driver circuit with the reference voltage, and generates the activation signal in response to the bus voltage exceeding the reference voltage.

10. The driver circuit recited in claim 8, wherein the fault circuit includes a temperature sensing circuit for detecting a temperature of a driver board of the driver circuit.

11. The driver circuit recited in claim 10, wherein the fault circuit generates the activation signal in response to a voltage across the temperature sensing circuit exceeding the reference voltage.

12. The driver circuit recited in claim 8, comprising a current sensing circuit for detecting current flowing out of the LED tube light and creating an over current voltage based on the current flowing out of the LED tube light.

13. The driver circuit recited in claim 12, wherein the fault circuit generates the activation signal in response to the over current voltage exceeding the reference voltage.

14. A lighting system, comprising:

a fluorescent ballast;

a light emitting diode (LED) tube light; and

a driver circuit for powering the LED tube light, the driver circuit comprising;

an input for connection to the fluorescent ballast;

a rectifier for converting AC power received from the input into DC power, the rectifier including a rectifier input;

a switch electrically connected to the rectifier input, wherein the switch is activated to create a short circuit at the rectifier inputs in response to receiving an activation signal;

a fault circuit electrically connected to the switch, wherein the fault circuit generates the activation signal in response to detecting at least one of an over voltage, an over temperature, and an over current condition of the driver circuit;

a charge pump circuit for providing substantially constant DC current to the fault circuit; and

a reference voltage circuit generating a reference voltage, wherein the reference voltage is used by the fault circuit as a reference value to determine the over voltage, the over temperature, and the over current condition of the driver circuit.

15. The lighting system recited in claim 14, wherein the fault circuit compares a bus voltage of the driver circuit with the reference voltage, and generates the activation signal in response to the bus voltage exceeding the reference voltage.

16. The lighting system recited in claim 14, wherein the fault circuit includes a temperature sensing circuit for detecting a temperature of a driver board of the driver circuit.

17. The lighting system recited in claim 16, wherein the fault circuit generates the activation signal in response to a voltage across the temperature sensing circuit exceeding the reference voltage.

18. The lighting system recited in claim 14, comprising a current sensing circuit for detecting current flowing out of the LED tube light and creating an over current voltage based on the current flowing out of the LED tube light.

19. The lighting system recited in claim 18, wherein the fault circuit generates the activation signal in response to the over current voltage exceeding the reference voltage.

20. A driver circuit for powering a load, comprising:

an input for connection to a ballast;

a rectifier for converting AC power received from the input into DC power, the rectifier including a rectifier input;

a switch electrically connected to the rectifier input, wherein the switch is activated to create a short circuit at the rectifier inputs in response to receiving an activation signal;

a fault circuit electrically connected to the switch, wherein the fault circuit generates the activation signal in response to detecting at least one of an over voltage, an over temperature, and an over current condition of the driver circuit; and

a reference voltage circuit generating a reference voltage, wherein the reference voltage is used by the fault circuit as a reference value to determine the over voltage, the over temperature, and the over current condition of the driver circuit.

21. The driver circuit recited in claim 20, wherein the fault circuit compares a bus voltage of the driver circuit with the reference voltage, and generates the activation signal in response to the bus voltage exceeding the reference voltage.

22. The driver circuit recited in claim 20, wherein the fault circuit includes a temperature sensing circuit for detecting a temperature of a driver board of the driver circuit.

23. The driver circuit recited in claim 22, wherein the fault circuit generates the activation signal in response to a voltage across the temperature sensing circuit exceeding the reference voltage.

24. The driver circuit recited in claim 20, comprising a current sensing circuit for detecting current flowing out of the load and creating an over current voltage based on the current flowing out of the load.

25. The driver circuit recited in claim 24, wherein the fault circuit generates the activation signal in response to the over current voltage exceeding the reference voltage.