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

Last Updated: June 02, 2021 01:45 PM

Circuits Designed by Dave Johnson, P.E. :

 Fake TV Camera Flasher -  After having my doorbell rung several times in the middle of the night by some kids, I decided to install some fake TV cameras around the outside of my house.  I was not satisfied with the LED lights on the cameras.  The heavy current drain of the original circuit meant I would have to replace the battery every few months.  So, I removed the original LED driver and added my own simple flashing circuit.   . . . Circuit by David Johnson P.E.-August, 2017

Fireflies_In_Jar_Solar_Light -  When I was a kid, growing up in Illinois, I remember catching fireflies and putting them into a jar.  I loved watching them flashing away at night.  Later, I would let them out to live another day. . . . Hobby Circuit by David Johnson P.E.-September, 2017

Flameless LED Candle Power Boost  -  Most flameless candles are now quite simple circuits.  They consist of nothing more than a power switch, a battery and a special flickering LED. The special LED might work fine for a candle but it is not bright enough for the touch.  To boost the power of this flickering device, you can remove that LED from a flameless candle and insert into the circuit shown below.  This circuit extracts the flickering signal from the special LED and uses the signal to drive 5 super bright yellow LEDs at a peak current of 20ma each. . . . Dave Johnson, Lubbock TX-DC Magazine - Issue 13 Nov 2010

Flashing High-Power LED  -  Power LEDs are becoming more popular these days.  The DC input power to these devices ranges from 1 watt to 5 watts.  Normal LEDs only receive about 0.  05 watts.  At this higher power, these devices can emit a lot of light . . . Dave Johnson, Lubbock TX (Aug 10, 2008)-DC Magazine - Issue 7 Mar 2010

Flashing LED Advertising Badge #1 - I 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 . . . Hobby Circuit designed by David A. Johnson P.E.-March, 2002

Flashing LED Power Indicator  - This circuit flashes a power indicator LED to keep the average current low. . . Circuit by David A. Johnson P.E.-June, 2000

Flashing Light to simulate Car Alarm - Whenever the car’s ignition is turned off, this circuit activates a flashing LED, which can be positioned to appear as an active alarm system . . . Hobby Circuit designed by David A. Johnson P.E.-October, 2005

Generate 0.5v Negative Supply - A while back someone needed a simple way to generate a negative 0.5v supply from a conventional transformer type AC to DC power supply.  The circuit below uses a couple schottky diodes and a filter capacitor to perform the feat . . . Hobby Circuit designed by Dave Johnson P.E.-July, 2011


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

Fader Switch Uses Inexpensive Controller -  12-Nov-09 EDN-Design Ideas Control the brightness of an LED or incandescent lamp Design by William Grill, Lenexa, KS

Fading LEDs -  Two strips of LEDs fading in a complementary manner; 9V Battery-operated portable unit __ Contact: Flavio Dellepiane, fladello @ tin.it

Fading Red Eyes -  This is a combination clock timer and solar panel charge controller used to maintain a deep cycle battery from a solar panel.  The timer output is used to control a 12 volt load for a 49 __ Designed by Bill Bowden

Fading Red Eyes -  can be used to slowly illuminate and fade a pair of red LEDs __ Designed by Bill Bowden

Failsafe multichip LED Module driver -  EDN-Design Ideas 05/12/2014     Keep a power LED module with multiple strings operating despite fault conditions Design by Subodh Johri

Fake TV Camera Flasher -  After having my doorbell rung several times in the middle of the night by some kids, I decided to install some fake TV cameras around the outside of my house.  I was not satisfied with the LED lights on the cameras.  The heavy current drain of the original circuit meant I would have to replace the battery every few months.  So, I removed the original LED driver and added my own simple flashing circuit.   . . . Circuit by David Johnson P.E.-August, 2017

Fancy LEDS -  The idea of this project came from my youngest son.  He was dreaming of a small tool able to write symbols or pictures on a screen.  As a graphic LCD  (even bought at Crownhill :)) was too expensive  (or too easy??) , the solution adopted was to pilot a matrix of Leds.  This way, 

Fantastic Atom Expander -  Here is the schematic, PC board pattern, and parts placement for a "Fantastic Atom Expander".  This circuit produces an "exploding atom" effect using 98 LEDs. __ Designed by Aaron Cake

Fine Control SuperBright LED Pulser -  Four timing controls12V supply; Suitable for Halloween or Christmas props __ Contact: Flavio Dellepiane, fladello @ tin.it

Finely Tune the Hue Of Blue-Light Sources -  03/17/11  EDN-Design Ideas Get 32 grades of hues between royal-blue and cyan.  When coach cars of long-range trains comprised compartments for six to eight passengers, the passengers could choose either “white” or deepblue light.  The blue light helped passengers sleep, even when they were not in full darkness.  The circuit in Figure 1 lets you set a hue of blue light that can match your favorite blue color.  Although you can accomplish this task with another circuit  (Reference 1) , this circuit provIdeas a finer adjustment of color and uses a narrower range from cyan to royal blue.  The light is a mixture from two power LEDs, both from Avago Technologies.   Design by Marián Štofka, Slovak University of Technology, Bratislava, Slovakia

Fireflies_In_Jar_Solar_Light -  When I was a kid, growing up in Illinois, I remember catching fireflies and putting them into a jar.  I loved watching them flashing away at night.  Later, I would let them out to live another day. . . . Hobby Circuit by David Johnson P.E.-September, 2017

Five-To 10-LED Flashlight Runs At 3V  -  12/15/08  EDN Design Ideas:  With this simple circuit and easy-to-find components, you can convert bulb flashlights into energy-efficient, bright LED flashlights Design by GY Xu, XuMicro, Houston, TX

Flameless LED Candle Power Boost  -  Most flameless candles are now quite simple circuits.  They consist of nothing more than a power switch, a battery and a special flickering LED. The special LED might work fine for a candle but it is not bright enough for the touch.  To boost the power of this flickering device, you can remove that LED from a flameless candle and insert into the circuit shown below.  This circuit extracts the flickering signal from the special LED and uses the signal to drive 5 super bright yellow LEDs at a peak current of 20ma each. . . . Dave Johnson, Lubbock TX-DC Magazine - Issue 13 Nov 2010

Flash an LED From Ac-Mains Power  -  01/06/11 EDN Design Ideas:  A few components create an illuminated switch Design by TA Babu, Chennai, India

Flasher - LEDs  -  This is a very simple project using a printed circuit board and 8 components.  It will flash an ordinary 3mm or 5mm (1/8" or 1/4") LED at a rate of about one flash per second.  __ Collin Mitchell

Flashing Beacon  -  A flashing beacon has many uses.  It can be employed as a distress signal on highways or as a direction pointer for parking lots, hospitals, hotels, etc.  Here we present a__ Electronics Projects for You

Flashing Heart  -  This circuit was made for my wife's birthday.  It is capable of flashing five strings of LEDs with different frequencies.  It also has a connector for an 8 Ohm loudspeaker and two connectors for the small PCB's that are contained in musical greeting cards.  In this way the circuit will play alternatingly two room filling tunes at regular time intervals.  After a w __ Designed by Michel Van den Bergh On Electronics

Flashing High Intensity LED 3rd Brake Light  -  This circuit to make a flashing 3rd brake light assembly was designed to be easy to locate all the needed components and reasonably in expensive to build__ National Semiconductor

Flashing High-Power LED  -  Power LEDs are becoming more popular these days.  The DC input power to these devices ranges from 1 watt to 5 watts.  Normal LEDs only receive about 0.  05 watts.  At this higher power, these devices can emit a lot of light . . . Dave Johnson, Lubbock TX (Aug 10, 2008)-DC Magazine - Issue 7 Mar 2010

Flash an LED From Ac-Mains Power -  01/06/11 EDN-Design Ideas A few components create an illuminated switch Design by TA Babu, Chennai, India

FlasherLEDs -  This is a very simple project using a printed circuit board and 8 components.  It will flash an ordinary 3mm or 5mm  (1/8" or 1/4") LED at a rate of about one flash per second.  __ Collin Mitchell

Flashing Beacon -  A flashing beacon has many uses.  It can be employed as a distress signal on highways or as a direction pointer for parking lots, hospitals, hotels, etc.  Here we present a...__ Electronics Projects for You

Flashing Heart -  This circuit was made for my wife's birthday.  It is capable of flashing five strings of LED's with different frequencies.  It also has a connector for an 8 Ohm loudspeaker and two connectors for the small PCB's that are contained in musical greeting cards.  In this way the circuit will play alternatingly two room filling tunes at regular time intervals.  After a w __ Designed by Michel Van den Bergh On Electronics

Flashing High Intensity LED 3rd Brake Light -  This circuit to make a flashing 3rd brake light assembly was designed to be easy to locate all the needed components and reasonably in expensive to build__ National Semiconductor

Flashing Indicators -  Need to flash "turn indicators" using a 555 and a single 20 amp relay.  Here is our suggestion.  The timing resistor needs to be selected for the appropriate flash-rate.  __ 555-Timer

Flashing LED -  This simple project makes a good low-cost first project to check your soldering skills and learn to identify common components.  The LED flashes at about 3Hz  (3 flashes per second) .   __ Designed by John Hewes

Flashing LED Advertising Badge #1 -  I 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 . . . Hobby Circuit designed by David A. Johnson P.E.-March, 2002

Flashing LED Power Indicator -  This circuit flashes a power indicator LED to keep the average current low. . . Circuit by David A. Johnson P.E.-June, 2000

Flashing LED using 555 timer -  This circuit uses the 555 timer in an Astable operating mode which generates a continuous output via Pin 3 in the form of a square wave.  This turns the LED  (D1) on and off.  The speed at which the LED  (D1) is turned on and off is set by the values of R1 and R2.  __ 555-Timer

Flashing LED with PIC12F629 -  This is the first example that you should to know how to set output pin.  In this example, GPO is set as an output.  LED1 will be turn-on when GP0 is set high and LED1 wiil be turn-off when GP0 is set low.  This example use 4MHz internal clock.  

Flashing LED-Based Solar Engine -  Voltage-Controlled Solar Engine:This design uses a flashing LED to determine the solar engine's voltage trip level.   __ Designed by Wilf Rigter

Flashing Light to simulate Car Alarm -  Whenever the car’s ignition is turned off, this circuit activates a flashing LED, which can be positioned to appear as an active alarm system . . . Hobby Circuit designed by David A. Johnson P.E.-October, 2005

Flashing Railroad Lights -  This circuit flashes two red LEDs for a model railway crossing.  __ 555-Timer

Flashing Red LED Light-1970's Style Caboose Marker -  A circuit that drives a red LED from a 1.5 volt battery and simulates an incandescent light.  Duty cycle can be changed by selecting resistor values __ Designed by Dick Cappels

Flashing-LED Battery-status Indicator -  Signals when an on-circuit battery is exhausted; 5V to 12V operating voltage __ Contact: Flavio Dellepiane, fladello @ tin.it

Flicker Lamp -  Having bought a cute little ‘paraffin lamp’ from a cut price shop, I decided to make it a little more interesting.  Its battery powered of course but its continuous shine and simple on / off ‘wick control’ did not make for anything like a close simulation of the real thing.  So, I replaced the on / off control with a variable potentiometer and I added flicker! __ Contact: Karen's Microprocessor Projects

Flickering Fire Effect -  This simple circuit uses four low-Wattage colored bulbs and four fluorescent lamp starters to make nice flickering flame effect

Flickering Lights -  Halloween flickering lights __ Designed by Wolf Stone

Flying inductor LED series voltage boost -  A circuit that goes in series with a white LED and a 1.5 volt cell to make > 3 Volts to drive a white LED __ Designed by Dick Cappels

Four DIPs provide as many as 80 sequential-LED outputs -  08/21/08 EDN-Design Ideas A simple circuit uses HCMOS parts and adds one 74HC540 to multiplex the outputs of two 4017 counters for as many as 80 outputs Design by Greg Carkner, Cobourg, ON, Canada

Four Output (-6.5V AT 500uA, 20V AT 500uA, 10V AT 2mA, 5 LED) Supply for Color LCD Displays -  From a 2.7V to 4.2V input, the LT1944 can generate 3 required bias voltages  (-6.5V AT 500uA, 20V AT 500uA, 10V AT 2mA) and drive a string of 5 white LEDs for backlighting __ Linear Technology/Analog Devices App Note, Mar 24, 2010

Full Circle LED -  Schematic + Info + pictures __ Designed by Lennie Zink

Full Color USB LED-Controller -  Microcontroller : Microchip PIC18F2550 Sensor : DS18S20 temperature sensor Video: Temperature based color control CPU load based color control Screen based color control License: The source code of this work is licensed under a __ Designed by Steffen Schütte

Garage Light Indicator LED -  This is the simplest possible way to power an LED off 115VAC.    I epoxied a high-brightness yellow LED into the switch plate to my garage light.  The light switch is inside my house, but the garage light cannot be seen when the door is closed.    This has cau __ Designed by Andrew R. Morris

Generate 0.5v Negative Supply -  A while back someone needed a simple way to generate a negative 0.5v supply from a conventional transformer type AC to DC power supply.  The circuit below uses a couple schottky diodes and a filter capacitor to perform the feat . . . Hobby Circuit designed by Dave Johnson P.E.-July, 2011

Get Four Colors From 2 Bits -  08/12/10 EDN-Design Ideas Using a three-color LED, you can get red, green, blue, and mixtures such as white light.   Design by Marián Štofka, Slovak University of Technology, Bratislava, Slovakia

Get More Than Three Colors from a Dot Matrix LED  -  06/05/98 EDN-Design Ideas To generate high voltages with proper insulation between  "hot node" and  rest of  circuitry, a car ignition coil can function in place of a high-voltage transformer.  se coils have voltage ratings of approximately 20 kV.    Design by W Kurdthongmee, Nakorn Si Thammarat, Thailand

Giant T-shaped LED matrix display board for financial applications containing 275 8x8 LED Modules -  A giant T-shaped LED matrix display board for financial applications containing 275 8x8 LED modules.  This was a project for my employer, but unfortunately another of those kinds of projects which was never quite finished.  Click the photos below for larger versions __ Designed by Hans Summers

Ginormous 7-Segment LED Panel Meter Display -  Have you ever had the need for a digital display that can be read from across the room? How about across the factory? How about fifty or even a hundred metres away?__ SiliconChip

GrantronICs Projects Christmas Tree -  flashes LEDs mounted to Christmas tree shape PCB, kit from kitsrus.  com __ Designed by © Grantronics Pty Ltd

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