Lighting system and method

• US 7,071,627 B2
• Filed: 02/11/2002
• Issued: 07/04/2006
• Est. Priority Date: 06/29/2001
• Status: Expired due to Term

• Current Assignee: Continental Automotive Systems, Inc. (Continental AG)
• Original Assignee: Temic Automotive of North America, Incorporated (Continental AG)
• Inventors: Miller, Peter
• Primary Examiner(s): Wong, Don
• Assistant Examiner(s): Lie, Angela M
• Application Number:
  US10/362,409
• Publication Number:
  US 20050017654A1
• Time in Patent Office: 1,604 Days
• Field of Search: 315/82, 315/291, 315/247
• US Class Current: 315/141
• CPC Class Codes: H05B 39/047 with pulse width modulation from a DC power source
• CPC Class Codes: Y02B 20/00 Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps

Abstract

A lighting system and method (1) is disclosed having a pulse-width modulation (PWM) lighting system and method for use in environments where the PWM ratio is variable, for example though not exclusively, in 42V and/or dual-voltage electrical systems in automotive applications.

Claims

1. A lighting system for driving light bulbs having a lower voltage tolerance than the voltage supply to the system, comprising:

a pulse width modulator converter supplied with a required voltage from a system source voltage supply of the system for regulating an average output signal of the pulse width modulator converter supplied to a register to selectively connect the output signal of the pulse width modulator converter to a light bulb selected by the converter supply from a plurality of light bulbs, each light bulb having a lower voltage tolerance than the system voltage, the register and converter synchronised via a clock source, wherein the converter drives a single light bulb at any one time even with a variable PWM mark-space ratio.

2. A lighting system as claimed in claim 1, wherein the system further comprises of a light bulb driver connected between each light bulb and register.

3. A lighting system as claimed in claim 1, wherein the pulse width modulator comprises of a comparator with one input receiving a required voltage, and another input receiving the output signal of the converter from a D-type flip-flop that receives the output signal of the comparator, feedback through a resistor and capacitor, for regulating the average output signal.

4. A lighting system as claimed in claim 2, wherein the pulse width modulator comprises of a comparator with one input receiving a required voltage, and another input receiving the output signal of the converter from a D-type flip-flop that receives the output signal of the comparator, feedback through a resistor and capacitor, for regulating the average output signal.

5. A lighting method for driving light bulbs having a lower voltage tolerance than the voltage supply to the system, comprising the steps of:

supplying a requited voltage from system source voltage from a system source voltage supply;

regulating an average output signal from a pulse width modulator converter supplied with the system source voltage from the source system supply;

supplying the regulated average output signal to a register, the register and converter synchronised via a clock source; and

selectively connecting the output signal of the pulse width modulator converter from the register to a single light bulb at any one time from a plurality of light bulbs, even with a variable PWM mark-space ratio, wherein each light bulb having a lower voltage tolerance than the system voltage supply.

6. A lighting method as claimed in claim 5, wherein the step of selectively connecting the output signal of the pulse width modulator converter from the register to a single light bulb further comprises a light bulb driver connected between each light bulb and register.

7. A lighting method as claimed in claim 5 wherein the step of regulating an avenge output signal from the pulse width modulator converter further comprises comparing at a comparator in the pulse width modulator converter one input receiving the required voltage, with another input receiving the output signal from a D-type flip-flop that receives the output signal of the comparator, feedback through a resistor and capacitor, for regulating the average output signal.

8. A lighting method as claimed in claim 6 wherein the step of regulating an average output signal from the pulse width modulator converter further comprises comparing at a comparator in the pulse width modulator converter one input receiving the required voltage, with another input receiving the output signal from a D-type flip-flop that receives the output signal of the comparator, feedback through a resistor and capacitor, for regulating the average output signal.