Electronic Circuits and electronic circuits, electronic schematics plus an extensive resource for hobbyists, inventors and engineers

DiscoverCircuits.com has links to 45,000+ electronic circuits, cross-referenced
into 500+ categories.    We have searched the web to help you find quick design ideas.

HOME Schematics Hobby Corner Dave's Circuits Electronic Resources Contact Info
Imagineering Ezine    Discover Solar Energy Dave Johnson & Associates Faraday Touch Switches
Welcome to DiscoverCircuits.com - online since 2002

See Media Kit for
Advertising Opportunities

Attention Designers:  Please alert us by eMail if we have linked to sites
where your original material has been copied without your permission.
We will change to the LINK to your site.  
Thank you.

 


Light Emitting Diodes (LED) Circuits
LEDs:   #'s - B     C - G      H - L       M - P       Q - T     U - Z 
 

Last Updated: October 25, 2017 05:10 AM

Circuits Designed by Dave Johnson, P.E. :

  LED Array powered by 24 VA - C24vac is a popular voltage.  It is often used in low voltage lighting systems and industrial controls.  It is much less dangerous than 120vac/240vac line voltages.  This hobby circuit below is one method to efficiently power a cluster of 7 white LEDs from 24vac. . . . Hobby Circuit designed by David Johnson P.E.-December, 2009

 LED Camping Lantern with DimmerA while back I received an email from a Discover Circuits visitor who wanted to build his own LED camping lantern.  He wanted to use a single bright LED powered by 3 large alkaline D cells.  He also wanted to be able to dim the light intensity down to a low night light level, to extend the battery life.  The circuit below performs this task . . . Hobby Circuit designed by David A. Johnson P.E.-December, 2013

 LED Driver using Constant CurrentLEDs are current driven devices.  The light they produce is proportional to the current flowing though them.  One way to maintain a fairly steady light output is to keep the current through the LED fixed, even as the supply voltage may change.  A classic. . . Circuit by David A. Johnson P.E.-December, 2010

 LED Driver-WirelessThe circuit solves this problem by sending power to the LED through the plastic, using a magnetic coupling technique.  The circuit below can route power through plastic enclosures as thick as ¼ inch.  The circuit will not work through metal boxes . . . Hobby Circuit designed by Dave Johnson P.E.-November, 2008

 LED Flasher needs only 1.5 VOLTSTo squeeze even more energy from a alkaline battery cell, this circuit adds two transistors to a circuit similar to the above design to boost the efficiency.  A small 1.5 volt alkaline N cell should flash the LED for a full year.  It too uses a "charge pump" technique to provide a LED the needed voltage . . . Hobby Circuit designed by Dave Johnson P.E.-June, 2000

 LED Flasher that is Battery FreeLED flashers have been used for a wide variety of applications.  Some flasher units have been used in food and hardware stores, to draw attention to sale items and are often attached to boxes which dispense product discount coupons . . . Hobby Circuit designed by David Johnson P.E.-December, 2010

 LED Flasher Universal 3vThe electronic circuit below will flash any LED color with fixed current pulses powered by a 3v battery.  It uses a charge pump approach, which routes a constant current pulse through the LED, regardless of the LED voltage requirement.  Using this approach . . . Hobby Circuit designed by David Johnson P.E.-June, 2008

 LED Flasher-Wig/WagThis simple circuit will flash two LEDs in an alternating fashion . . . Hobby Circuit designed by David Johnson P.E.-December, 2004

 LED Flasher-Wireless CircuitWhen you would like to flash a LED through a thick plastic case without wires, use this hobby circuit.  It performs this feat.  It draws about 300ua of average current at 5v.  It can be powered from a supply ranging from 3v to 6v . . . Hobby Circuit designed by Dave Johnson P.E.-January, 2011

 LED Flashing Badge #1I have seen numerous flashing light badges at trade shows and conventions.  They are often handed out as gifts to promote some business.  The devices often use inefficient circuits, which cause the battery power source to be quickly depleted. . . Circuit by Dave Johnson P.E.-March, 2002

 LED Flashing Badge #2This circuit uses a CD4013 dual D Flip/Flop IC.  A single lithium battery will provide months of continuous LED flashing.  It also has a tiny push-button switch to turn on and off the light flashing. . . Circuit by David Johnson P.E.-March, 2002

LED_Light_for_Tool_Shed -  I have a lean-to 8ft by 12ft shed next to my house.  It is full of lawn chemicals and garden supplies.  There were times when I needed to get something from inside the shed during the dead of night.  Early on I had to use a flashlight.  But later, I installed a series of five 12v LED light strips on the ceiling.  Each strip contained 15 3v white LEDs.  The strip had 5 strings of three LEDs, wired in series, with a 150 ohm current limiting resistor. . . . Hobby Circuit by David Johnson P.E.-July, 2017

LED_Light_8_Solar_Cell -  I have been modifying a lot of solar garden and path lights for the last several years.  I buy some units from home improvement stores, then I gut them completely.  I take out the battery, electronic control board, LED and solar panel.  I then replace those components with new units.  I increase the size of the solar panel and battery.  I use a more efficient and brighter LED . . . Hobby Circuit by David Johnson P.E.-September, 2017

 LED Lighthouse FlasherThis was originally designed for a model in a HO train set.  It simulates the behavior of the light from a lighthouse.  The LED intensity gradually increases, then flashes with a bright light and finally decreases slowly in intensity . . . Hobby Circuit designed by David Johnson P.E.-July, 2006

 LED Lighthouse Flasher for HO Model Train  - HO train sets often have authentic looking scale model homes and buildings.  The hobby circuit below can be mounted inside a model lighthouse.  The electronic circuit drives a single LED lamp in such a way that it produces light which simulates the rotation . . . Hobby Circuit designed by David Johnson P.E.-July, 2006

 LED Pilot Light powered by AC LineThis simple circuit can be used to light a LED indicator lamp, powered from the 120vac line.  I have included component values for 240vac lines as well. . . Circuit by David A. Johnson P.E.-July, 2006

 LED Strings powered by AC LineThis shows 4 different ways to string white LEDs that are powered by a 120vac or 240vac power line.    The circuit was designed by Ken Schultz . . . Hobby Circuit designed by David A. Johnson P.E.-December, 2004


Links to electronic circuits, electronic schematics, designs for engineers, hobbyists, students & inventors:

LED_Light_8_Solar_Cell -  I have been modifying a lot of solar garden and path lights for the last several years.  I buy some units from home improvement stores, then I gut them completely.  I take out the battery, electronic control board, LED and solar panel.  I then replace those components with new units.  I increase the size of the solar panel and battery.  I use a more efficient and brighter LED . . . Hobby Circuit by David Johnson P.E.-September, 2017

LED Lighthouse Flasher -  This was originally designed for a model in a HO train set.  It simulates the behavior of the light from a lighthouse.  The LED intensity gradually increases, then flashes with a bright light and finally decreases slowly in intensity . . . Hobby Circuit designed by David Johnson P.E.-July, 2006

LED Lighthouse Flasher for HO Model Train  -  HO train sets often have authentic looking scale model homes and buildings.  The hobby circuit below can be mounted inside a model lighthouse.  The electronic circuit drives a single LED lamp in such a way that it produces light which simulates the rotation . . . Hobby Circuit designed by David Johnson P.E.-July, 2006

LED_Light_for_Tool_Shed -  I have a lean-to 8ft by 12ft shed next to my house.  It is full of lawn chemicals and garden supplies.  There were times when I needed to get something from inside the shed during the dead of night.  Early on I had to use a flashlight.  But later, I installed a series of five 12v LED light strips on the ceiling.  Each strip contained 15 3v white LEDs.  The strip had 5 strings of three LEDs, wired in series, with a 150 ohm current limiting resistor. . . . Hobby Circuit by David Johnson P.E.-July, 2017

LED Lighting Effects -  The original yoyo was equiped with 2 LEDs that lit up whend evice was spinning.  I decided to add a micro to give it some extra pazazz.  The trick here is to make unit work without a power switch.  The mercury switch is positioned so that it supplies power when unit is spinning.  After about 20 seconds, PIC shuts down in sleep modes,  __ Designed by Luhan Monat-Mesa Arizona

LED Lighting for Christmas -  Using light effects for decoration on festive occasions is a normal practice.  Designers are coming up with varieties of electronic circuits to fill the imagination of users.  Here is an easy-to-assemble circuit...__ Electronics Projects for You

LED Lighting For Dual-Filament Lamps -  Before we describe how it’s done, note that we recommend that the result be checked as having sufficient brightness for a stop & tail-light application.  That’s because the light output may be inadequate, depending on the tail-light lens and reflector assembly – so use any modified lamps with discretion! As shown, an additional diode  (D1) […]

LED Lighting for Your Car -  Replace your car's filament lamps with LED's for improved safety.  There are several designs to build, all using high- brightness LED's.__ SiliconChip

LED LoA - D -  The board supports driving two separate tri-color LEDs.  More can be setup inline if desired.  Currently the software only uses the second LED and its color represents the CPU load of the system in real-time.  Blue for idle and gradients light blue, green, yellow, orange, and finally red indicating heavy CPU utilization.  If the system fails to respond, the LED begins flashing RED to indicate a lack of communication from the software.  This lets you easily identify a crashed machine in a rack for example.  

LED Modulations (2 versions) -  Common Light Emitting Diodes  (LEDs) require a DC forward bias current of 10 to 20 mA for proper operation.  Typically the maximum DC current is 30 to 50 mA.  The color of light  (or wavelength λ) emitted from an LED depends on the semiconductor material used to fabricate the LED and this in turn determines the LED forward voltage at the operating current. __ Designed by M. Gallant

LED Mood Light -  This circuit makes a nice lamp that consumes little power, runs cool, and has an incredibly long lifetime.  The lamp puts out a warm yellow shade of light, the color may be adjusted by changing the number of red or green LED strings.   __ Designed by Forrest Cook

LED Moving Sign 7 x 10 -  This sign uses two LED arrays to form a 7 X 10 matrix.  It produces moving messages or animations stored in an EPROM.  It uses no microprocessor.   As in most electric signs, the LEDs are matrixed, and strobed very quickly.   __ Designed by Bob Blick

LED Musicolour: Light Up Your Music, Pt.1 -  Now you can have a kaleidoscope of colour which continually changes in time to music.  This consists of 16 strings of LEDs which are individually controlled by 16 frequency bands.  Louder signals in each of those bands means that the respective LED string will be brighter.  Use it for a Christmas light show, a disco or just for fun when playing music.__ SiliconChip

LED Musicolour: Light Up Your Music, Pt.2 -  The new LED Musicolour makes building a spectacular light and music show easier than ever.  In this second and final instalment, we explain how to build and test the unit and also detail how you can control it.__ SiliconChip

LED Noughts & Crosses -  Here’s a twist to the age-old game of noughts and crosses.  Instead of pen and paper, it uses nine 10mm tri-colour LEDs arranged in a 3 x 3 grid.  One player has nine red buttons while the other player has nine green, set out in identical grids.  The aim, of course, is to make three LEDs in a row glow the same colour – red or green! Pushing a red button causes the LED in the equivalent position on the grid to glow red in colour.  Likewise, pushing a green button lights the equivalent green LED.
__ Learning Electronics

LED or Incadescent 12 Volt Lamp Fader -  This circuit is similar to the "Fading Red Eyes" circuit    (in the LED section) used to fade a pair of red LEDs.  In this version, the lamps are faded by varying the duty cycle so that higher power incandescent lamps can be used without much power loss.  The switching waveform is generated by comparing two linear ramps  __ Designed by Bill Bowden

LED or Lamp Flasher -  Minimum parts countingImproved version; 3V battery operation __ Contact: Flavio Dellepiane, fladello @ tin.it

LED or Lamp Pulser -  Astonishing effect; 4.5V supply __ Contact: Flavio Dellepiane, fladello @ tin.it

LED Oscilloscope -  George Katz of Balgowlah Boys high in Sydney presented a solid state oscilloscope.  He says "probably the best advantage is its very small size and the fact that it can run off the power supply of the circuit being tested.  Although it has a low frequency range, it can still be used for most circuits.  Its poor resolution will still allow for most waveforms to be visualized.  ".  

LED Oscilloscope 1 -  Uses a matrix of 100 LED as a display __ Designed by shaunwilson19 @ yahoo.com

LED Photo Sensor -  Here's a circuit that takes advantage of the photo-voltaic voltage of an ordinary LED.  The LED voltage is buffered by a junction FET transistor and then applied to the inverting input of an op-amp with a gain of about 20.  This produces a change of about 5 volts at the output from darkness to bright light.  The 100K potentiometer can be set so that the output is around 7 volts in darkness and falls to about 2 volts in bright light __ Designed by Bill Bowden

LED Photodetector -  Using the light-emitting diode as the photodetector

LED Pilot Light (AC or DC) -  LED current is constant between 6 and 8 mA at5 to30Vdc.   __ Designed by Tony van Roon  VA3AVR

LED Pilot Light powered by AC Line -  This simple circuit can be used to light a LED indicator lamp, powered from the 120vac line.  I have included component values for 240vac lines as well. . . Circuit by David A. Johnson P.E.-July, 2006

LED power meter -  Used for testing RF transmitters __ Contact: Collin Mitchell

LED Power Supply Has Battery Backup -  04/08/10 EDN-Design Ideas Power three to six LEDs from an ac- or dc-power source and charge a backup battery.   __ Circuit Design by Zhihong Yu, Juno Lighting Group, Des Plaines, I - L

LED power supply has battery backup -  Power three to six LEDs from an ac- or dc-power source and charge a backup battery.  LEDs find wide use in emergency lighting because of their high efficiency __ Designed by Zhihong Yu, Juno Lighting Group, Des Plaines, I - L;

LED Programmable Indicator -  This circuit uses CD4017 to program a bicolour LED in ten different modes with combinations of red and green.  __ Electronics Projects for You

LED Relay 9-Second Timer -  This circuit provides a visual 9 second delay using a 7 segment digital readout LED.  When the switch is closed, the CD4010 up/down counter is preset to 9 and the 555 timer is disabled with the output held high.  When the switch is opened,  __ Designed by Bill Bowden

LED Sand-Glass Timer -  This circuit simulates the old sand-glass timer.  A total of 32 LEDs create the effect of sand grains passing from the upper half of sand-glass to its lower half.  __ Electronics Projects for You

LED Scanner -  Here is a simple LED chaser simulating a scanner through the back and forth light effect.  It used high bright White LEDs to give the chaser effect.  The circuit uses an oscillator to produce fast pulses and a decade counter to drive the LEDs.  IC1 is designed as an astable multivibrator to give continuous positive pulses to the __ Designed by D Mohankumar

LED Scrolling Display -  Most outdoor LED displays and some indoor LED displays are built around individually-mounted LEDs.  A cluster of red, green and blue diodes is driven together to form a full-colour display.In a...__ Electronics Projects for You

LED Security Light with PIR Motion Sensor -  Here is one simple circuit of a general-purpose white LED security light with Passive Infrared  (PIR) Motion sensing mechanism.  At the heart of the circuit is a PIR sensor module SB0061.  SB0061 is a pyroelectric sensor module which developed for human body detection.  A PIR detector combined with a fresnel lens are mounted on a __ Designed by T.K. Hareendran

LED senses & displays Ambient light intensity -  09/05/07  EDN-Video Design IdeasExplains how an LED can double as a photosensor and a visual indicator of ambient-light intensity __ Circuit Design by Dhananjay V Gadre of India's Netaji Subhas Institute of Technology

LED senses & displays Ambient-light intensity -  11/09/06  EDN-Design Ideas LED doubles as photosensor and visual indicator of ambient-light intensity __ Circuit Design by Dhananjay V Gadre and Sheetal Vashist, ECE Division, Netaji Subhas Institute of Technology, New Delhi, India

LED Sensor Relay Tracker Schematic -  I have been looking for truly low cost and yet accurate conventional solar trackers.  The CdS tracker is pretty good but lacks accuracy and sensitivity.  I was thinking about using PV cells as the sensor.  I was experimenting with LEDs and noticed they generate voltage in sunlight.  Bingo!This got me to thinking __ Contact: Duane C. Johnson

LED Sequencer -  The model 4017 integrated circuit is a CMOS counter with ten output terminals.  One of these ten terminals will be in a "high" state at any given time, with all others being "low, " giving a "one-of-ten" output sequence.  If low-to-high voltage pulses are applied to the "clock"  (Clk) terminal of the 4017, it will increment its count, forcing the next output into a "high" state __ Designed by © EETech Media, LLC.

LED Sequencer -  This circuit is the essence of many "chaser" schemes that provide animation in advertising displays, lighting ten LEDs sequentially.   __ Designed by Arthur Harrison

LED Shine -  Scroll to this one.  If you wish to have some really nice looking LED's shining out of your equipment panel, you may try the following trick: pass repeatedly a fine sandpaper on the surface of any transparent and clear LED until the same surface is all worked out to a whitish look.   __ Designed by di Domenico Di Mario

LED Solar Lantern Lights -  Circuit of the LED solar lantern lights presented here is built around one 6V/1W Solar Panel  (PhotoVoltaic Panel) and a 4V/800mAh Lead-Acid Battery.  Here, commonly available 5mm White Straw Hat LEDs are used as the light source.  how does the solar lantern circuit works DC 6V supply from the solar panel is fed to the __ Designed by T.K. Hareendran

LED strings driven by current source/mirror -  EDN-Design Ideas 11/04/2016    This unusual dual-output current source can, for example, drive LED strings at any desired current ratio __ Circuit Design by Luca Bruno

LED Strings Powered by AC Line -  This shows 4 different ways to string white LEDs that are powered by a 120vac or 240vac power line.   __ Designed by Ken Schultz, drawn Dave Johnson 12.18.2004

   <<<         >>>

LEDs:   #'s - B     C - G      H - L       M - P       Q - T     U - Z 

 


Imagineering Ezine    Discover Solar Energy Dave Johnson & Associates Faraday Touch Switches



 About Us   |  Advertise on DiscoverCircuits.com   |   Report Broken Links  |    Link to DiscoverCircuits.com  |   
Privacy Policy


Discovercircuits.com endeavors to credit original designers.   Please alert us by eMail so we can
delete links to material that have been copied without your permission
.   Thank you.


© Copyright of all original material on this website is the property
of David A. Johnson, P.E. (Dave Johnson & Associates ) unless otherwise noted.  

Linking is ALLOWED but COPYING any content or graphics to your web site is EXPRESSLY PROHIBITED.
All material is provided "as is" without guarantees or warranty of any kind, either expressed or implied.