GB2453314A - Fully variable LED brightness using a digital control method - Google Patents

Fully variable LED brightness using a digital control method Download PDF

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Publication number
GB2453314A
GB2453314A GB0715492A GB0715492A GB2453314A GB 2453314 A GB2453314 A GB 2453314A GB 0715492 A GB0715492 A GB 0715492A GB 0715492 A GB0715492 A GB 0715492A GB 2453314 A GB2453314 A GB 2453314A
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GB
United Kingdom
Prior art keywords
application
led
fully
control method
digital control
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
GB0715492A
Other versions
GB0715492D0 (en
Inventor
Kenneth John Jewell
Noel Alain Vinck
Gullwig Ltd
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to GB0715492A priority Critical patent/GB2453314A/en
Publication of GB0715492D0 publication Critical patent/GB0715492D0/en
Publication of GB2453314A publication Critical patent/GB2453314A/en
Withdrawn legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
    • H05B45/10—Controlling the intensity of the light
    • H05B45/14—Controlling the intensity of the light using electrical feedback from LEDs or from LED modules
    • H05B33/0833—

Landscapes

  • Circuit Arrangement For Electric Light Sources In General (AREA)

Abstract

An LED controller receives a variable Pulse Width Modulated signal, which is then inverted. The inverted signal is level shifted to a current limited voltage level. This signal is then filtered and the output is used to drive a FET, IGBT, Transistor or other current amplifying device to switch the LED load. The LED brightness level is controlled by the width of the pulse being generated by the micro-controller, other IC or other source. This application can also be fabricated into a specifically designed (IC) Integrated Circuit therefore reducing the need for external hardware and no micro-controller would be required. This application can be integrated into any product or application that requires fully variable (LED) Light Emitting Diode brightness using a digital control method. This application will allow any LED's to be fully dimmed from completely off to fully on (0 to 100%) without any noticeable stepping.

Description

Fully variable LED brightness using a digital control method
Description:
A written description of how the application works is detailed on this page.
There are essentially 2 parts of the application: i) A firmware application layer which is programmed into a micro-controller, other IC or other source which essentially outputs a variable (PWM) Pulse Width Modulated signal. The firmware uses a logarithmic lookup table to vaiy the width of the pulse output.
The defined resolution of the dimming depends on how many values are in
the lookup table.
ii) The hardware application: Current is monitored through a simple shunt and the voltage drop across the shunt is compared to a preset reference voltage which keeps the output of an operation amplifier at a steady voltage. This provides a constant current source for the LED's to prevent them being over-driven.
The PWM signal from the micro-controller, other IC or other source is inverted through a single transistor, the voltage level of the inverted PWM signal is level-shifted to a voltage that depends on the output of the current limit circuit.
The PWM signal is filtered with a low pass filter producing a stable proportionate DC voltage before being fed to a FET, IGBT, Transistor or other current amplifying device whose output switches the LED load.
See figure 1 on the Drawing page.
This application can also be fabricated into a specifically designed (IC) Integrated Circuit therefore reducing the need for external hardware and no micro-controller

Claims (3)

  1. Fully variable LED brightness using a digital control method Claims: The application claims that: 1) The application described can be integrated into any product or application that requires fully variable (LED) Light Emitting Diode brightness using a digital control method.
  2. 2) This application will allow any LED's to be fully dimmed from completely off to fully on (0 to 100%) without any noticeable stepping.
  3. 3) This application can also be fabricated into a specifically designed (IC) Integrated Circuit therefore reducing the need for external hardware and no micro-controller would be required.
GB0715492A 2007-08-09 2007-08-09 Fully variable LED brightness using a digital control method Withdrawn GB2453314A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB0715492A GB2453314A (en) 2007-08-09 2007-08-09 Fully variable LED brightness using a digital control method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB0715492A GB2453314A (en) 2007-08-09 2007-08-09 Fully variable LED brightness using a digital control method

Publications (2)

Publication Number Publication Date
GB0715492D0 GB0715492D0 (en) 2007-09-19
GB2453314A true GB2453314A (en) 2009-04-08

Family

ID=38543270

Family Applications (1)

Application Number Title Priority Date Filing Date
GB0715492A Withdrawn GB2453314A (en) 2007-08-09 2007-08-09 Fully variable LED brightness using a digital control method

Country Status (1)

Country Link
GB (1) GB2453314A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2826339A1 (en) * 2012-03-12 2015-01-21 Osram Sylvania Inc. Current control system
CN107000636A (en) * 2014-12-15 2017-08-01 Fca美国有限责任公司 By the two level indicator light adjusting circuits and backlight control of PWM backlight feedback controls
EP3519879A4 (en) * 2016-09-30 2020-05-06 Edward B. Stoneham Apparatus and methods for controlling led light flux

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040251854A1 (en) * 2003-06-13 2004-12-16 Tomoaki Matsuda Power supply for lighting
WO2007055519A1 (en) * 2005-11-09 2007-05-18 Yuyang Telecom Co., Ltd Constant current pulse width modulation driving circuit for light emitting diode
EP2016801A2 (en) * 2006-05-05 2009-01-21 Linear Technology Corporation Circuit and methodology for supplying pulsed current to a load, such as a light emitting diode

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040251854A1 (en) * 2003-06-13 2004-12-16 Tomoaki Matsuda Power supply for lighting
WO2007055519A1 (en) * 2005-11-09 2007-05-18 Yuyang Telecom Co., Ltd Constant current pulse width modulation driving circuit for light emitting diode
EP2016801A2 (en) * 2006-05-05 2009-01-21 Linear Technology Corporation Circuit and methodology for supplying pulsed current to a load, such as a light emitting diode

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2826339A1 (en) * 2012-03-12 2015-01-21 Osram Sylvania Inc. Current control system
EP2826339B1 (en) * 2012-03-12 2021-07-28 Osram Sylvania Inc. Current control system
CN107000636A (en) * 2014-12-15 2017-08-01 Fca美国有限责任公司 By the two level indicator light adjusting circuits and backlight control of PWM backlight feedback controls
CN107000636B (en) * 2014-12-15 2019-11-19 Fca美国有限责任公司 By the two level indicator light adjusting circuits and backlight control circuit of PWM backlight feedback control
EP3519879A4 (en) * 2016-09-30 2020-05-06 Edward B. Stoneham Apparatus and methods for controlling led light flux

Also Published As

Publication number Publication date
GB0715492D0 (en) 2007-09-19

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Legal Events

Date Code Title Description
WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)