LED Lamp System

• US 20140077722A1
• Filed: 09/17/2012
• Published: 03/20/2014
• Est. Priority Date: 09/17/2012
• Status: Active Grant

• Current Assignee: Energy Focus, Inc.
• Original Assignee: Energy Focus, Inc.
• Inventors: Takacs, Laszlo A., Buelow, Roger F., Kralj, Tomislav
• Granted Patent: US 9,204,504 B2
• Time in Patent Office: Days
• US Class Current: 315/247
• CPC Class Codes: H05B 45/14 using electrical feedback from LEDs or from LED modules
• CPC Class Codes: H05B 45/3578 Emulating the electrical or functional characteristics of discharge lamps
• CPC Class Codes: H05B 45/37 Converter circuits
• CPC Class Codes: Y02B 20/30 Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Abstract

Disclosed is an LED lamp system designed to fit into a fluorescent lamp fixture and to utilize a fluorescent lamp power supply contained in the fixture and receiving power from AC mains. The LED lamp system includes an LED driver which comprises a power factor corrected driver circuit for achieving a power factor of at least about 0.8. The LED driver further comprises a current control circuit, responsive to the presence of a three-wire magnetic ballast in the fluorescent lamp power supply, for increasing the LED operating current above the nominal rated LED operating current and to a level sufficient to achieve power factor of the LED driver of at least about 0.8.

Claims

1. An LED lamp system designed to fit into a fluorescent lamp fixture and to utilize a fluorescent lamp power supply contained in the fixture and receiving power from AC mains, the LED lamp system including an LED driver arrangement which comprises:

a) a power factor corrected driver circuit for presenting a power factor to the AC mains of at least about 0.8; and

b) a current control circuit, responsive to the presence of a three-wire magnetic ballast in the fluorescent lamp power supply, for increasing the LED operating current above the nominal rated LED operating current and to a level sufficient to achieve power factor of the LED driver of at least about 0.8.

2. The LED lamp system of claim 1, wherein the current supplied to the LED drivel arrangement is greater than 200 milliamps.

3. The LED lamp system of claim 1, wherein the current supplied to the LED driver arrangement is within about five percent of 270 ma.

4. The LED lamp system of claim 1, wherein the power factor presented to the AC mains with the three-wire ballast is at least about 0.9.

5. The LED lamp system of claim 1, wherein the power factor presented to the AC mains with the three-wire ballast at least about 0.95.

6. The LED lamp system of claim 1, wherein the power factor presented to the AC mains with the three-wire ballast is at least 0.99.

7. The LED lamp system of claim 1, wherein the LED driver arrangement comprises ballast detection circuitry for detecting the presence a three-wire magnetic ballast in the fluorescent lamp power supply.

8. The LED lamp system of claim 7. wherein said ballast detection circuitry comprises:

a) means to cause the LED driver to achieve a first impedance by selection of level of current drawn by the LED driver from the fluorescent lamp power supply;

b) means to determine the a first power level used by the LED driver when the LED driver is at, said first impedance;

c) means to cause the LED driver to achieve a second impedance, greater than the first impedance, by selection of the level of current drawn by the LED driver from the fluorescent lamp power supply;

d) means to determine a second level power used by he LEO driver when the LED driver is at said second impedance; and

e) a three-wire magnetic ballast being indicated if the second power level exceeds the first power level and a two-wire magnetic ballast being indicated if the first power level exceeds the second power level.