Circuit for driving light-emitting diodes

• US 6,724,156 B2
• Filed: 01/16/2001
• Issued: 04/20/2004
• Est. Priority Date: 01/14/2000
• Status: Expired due to Term

• Current Assignee: Ip Technologies LLC
• Original Assignee: Design Rite LLC
• Inventors: Fregoso, Gilbert
• Primary Examiner(s): Lee, Wilson
• Application Number:
  US09/765,897
• Publication Number:
  US 20020014862A1
• Time in Patent Office: 1,190 Days
• Field of Search: 315/291, 315/308, 315/309, 315/307, 315/224, 315/209.R, 315/200.A, 315/185.R, 315/77, 315/78, 315/80, 315/82, 315/247, 362/800, 362/240, 362/183, 362/202, 362/206, 362/71
• US Class Current: 315/291
• CPC Class Codes: H05B 45/10 Controlling the intensity of the light
• CPC Class Codes: H05B 45/30 Driver circuits
• CPC Class Codes: H05B 45/37 Converter circuits

Abstract

A circuit efficiently drives light emitting diodes (LEDs). The circuit uses a switching regulator device instead of a standard resistor to limit current to the LEDs. The switching regulator device is in a closed loop with a current sensing device near the LED lamps. Feedback from this current sensing device switches the control method according to the current load regulating the voltage applied to the LEDs. An inductive storage device in the circuit allows the LEDs to be driven with minimal voltage input. Methods for intensifying and focusing the light produced by the LEDs driven by the circuit are also described.

Claims

1. A circuit for driving light emitting diodes comprising:

an inductive storage device, a switching regulator device, a rectifier, a filter, and a current sensing device wherein said inductive storage device is wire wound with an inductance between about 22 and 220 micro henries, wherein said switching regulator device comprises a programmable reference voltage source, an oscillation circuit, and an error amplifier, wherein said rectifier is a Schottky diode, and wherein said current sensing device and said switching regulator device are a temperature compensation circuit comprising an error amplifier, a current sensing resistor, at least two reference voltage resistors, and a transistor as a power driver, and wherein said circuit further comprises a low voltage power converter circuit capable of producing 3 volts and 20 milliamps when supplied with at least 0.8 volts input and a super enhanced MOSFET.

2. A circuit for driving light emitting diodes comprising:

an inductive storage device, a switching regulator device, a rectifier, a filter, and a current sensing device, wherein said inductive storage device is wire wound with an inductance between about 22 and 220 micro henries, wherein said switching regulator device is a CMOS PWM/PEM-control step-up switching regulator, wherein said rectifier is a Schottky diode, and wherein said current sensing device and said switching regulator device are a temperature compensation circuit comprising an error amplifier, a current sensing resistor, at least two reference voltage resistors, and a transistor as a power driver.

3. An illumination device, comprising:

a circuit comprising an inductive storage device, a switching regulator device, a rectifier, a filter, and a current sensing device, wherein said power source is at least one AAA battery, said switching regulator device comprises a programmable reference voltage source, an oscillation circuit and an error amplifier, and wherein said circuit further comprises a low voltage power converter circuit capable of producing 3 volts and 20 milliamps when supplied with at least 0.8 volts input and a super enhanced MOSFET.

4. A circuit for driving light emitting diodes comprising:

an inductive storage device, a switching regulator device, a rectifier, a filter, a current sensing device and a low voltage power converter circuit, wherein said low voltage power converter circuit produces 3 volts and 20 milliamps when supplied with at least 0.8 volts input.