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Light Emitting Diodes (LED) Circuits
LEDs:   #     A      B      C       D - E       F - H      I - K     L      M - O      P- R      S      T     U - V     W -Z

 

Last Updated: August 18, 2015 06:53 AM


Circuits Designed by Dave Johnson, P.E. :
9v Battery Voltage Monitor -  This circuit turns on a LED whenever the voltage of a standard 9v battery connected to the circuit drops below 7. 2 volts. It uses a LTC1440 comparator, which also contains a 1. 18v reference diode. In standby mode, the circuit draws only 4uA . . . [Circuit by Dave Johnson P.E.,  07/09/06]

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

5 Lamp/ LED Flash Driver -  General Description of the following circuit. This circuit is based around HT–2050 manufactured by HOLTEK semiconductors. It is a low cost, low-power C-MOS LSI designed for lamp andLED flash driver. It requires minimum external components. You can operate it with just two AAA cell or 3v Battery. . .  [Holtek HT2051]

 

50W White LED Automotive Headlamp Driver -  The LT3755, LT3755-1 and LT3755-2 are DC/DC controllers designed to operate as a constant-current source for driving high current LEDs. They drive a low side external N-channel power MOSFET from an internal regulated 7. 15V supply. The fixed frequency, current mode architecture results in stable operation over a wide range of . . .  [Linear Technology App Note - , Jul 20th 2010]

 

555 LED Flasher -  This is a small size LED flasher built with the 555 timer IC that is powered from 2 x 1. 5V batteries. The circuit can be used as a flashing metronome, dark room timer, memo-reminder or other similar applications. . . .  [Circuit posted by Popescu Marian]

 

555 Timer Drives Multiple LEDs from One NiMh Cell -  10/02/08  EDN Design Idea   Using a CMOS 555 timer, you can drive seven high-brightness LEDs from a single 1. 25V cell. . .  [by Chuck Irwin, Hendersonville, NC]

555 Timer Eliminates LED Driver’s Need for Microprocessor Control -  09/03/09  EDN Design Idea   A timer provides programming pulses for lower cost than a microprocessor. . .  [by Michael Day, Texas Instruments, Dallas, TX]

 

5x5x5 LED cube -  This month's featured Gadget Freak is provided by an old favourite of the blog, Peter Griffiths. He shares all the details necessary to build your own 5 x 5 LED cube. . . 

 

5x7 Display -  Sit back and take a big breath. You are about to take part in one of the best microcomputer (microprocessor) projects you have seen. It uses a PIC16F84 micro and you will be shown how to program the chip to create quite amazing effects. It's a simple project and you will be starting at the beginning of programming, so don't worry if you have never worked with a microprocessor before. . .  [email Colin Mitchell: talking AT tpg.com.au]

 

60 LED Clock -  This 1.5volt LED flasher runs more than a year on a single 'd" cell and alternately flashes 2 LEDs at about a 1 second rate. The circuit employs a 74HC14 CMOS hex inverter that will operate at very low voltages (less than 1 volt). One section is used as a squarewave oscillator (pins 1 and 2) , while the others are wired to produce a short 10mS pulse on alternate edges of the square wave so the LEDs will alternate back and forth. . .  [Bill Bowden, designer]

 

60 LED Clock -  As you can see see we have changed the circuit a little. For example, the 4093 NAND gate is now set to exactly 1 second clock pulses. The clock rate is determined by the resistor and capacitor combination on the 4093.If the resistor is 220k ohms and the capacitor is 4. 7uf then . . .  [Circuit design by Randy Linscott]

 

60V, Synchronous Step-Down High Current LED Driver -  03/01/14 EDN Design Note   This circuit provides much better performance and higher power handling than a Zener diode The meaning of the term “high power LED” is rapidly evolving. Although a 350mA LED could easily earn the stamp of “high power” a few years ago, it could not hold a candle to the 20A LEDs or the 40A laser diodes of today. High power LEDs are now used in DLP projectors, surgical equipment, stage lighting, automotive lighting, and other applications traditionally served by high intensity bulbs. . .  [by Hua (Walker) Bai, also see Linear Technology Design Note 508]

 

7 by 10 LED Moving Sign -  This sign I designed uses no microprocessor. It has an EPROM  and multiple counters. As in most electric signs, the LEDs are matrixed, and strobed very quickly. . . .  [Bob Blick's design]

 

7 Segment LED Counter -  This simple counter can be used to count pulses, as the basis for a customer counter (like you see at the doors of some stores) , or for anything else that may be counted. The circuit accepts any TTL compatible logic signal, and can be expanded easily (see Notes) . . .  [Circuit designed by Aaron Cake]

 

72 LED Clock -  In the circuit above, 60 individual LEDs are used to indicate the minutes of a clock and 12 LEDs indicate hours. The power supply and time base circuitry is the same as described in the 28 LED clock circuit above. The minutes section of the clock is comprised of eight 74HCT164 shift registers cascaded so that a single bit can be recirculated through the 60 stages i. . .  [Bill Bowden]

 

8 LEDs Make A 100-Division Voltmeter -  09/22/11  EDN Design Idea   Use a counter IC to drive two sets of four LEDs. The circuit in this Design Idea makes a voltmeter that reads to 0. 99V. The idea uses a counter IC to drive two sets of four LEDs (Figure 1). Each of these two sets represents a BCD (binary-coded-decimal) value. With all of the LEDs off, the voltmeter reads 0V. With all of the LEDs on, the reading is 0. 99V. Op Amp IC1A generates a predictable voltage ramp. . .  [by Raju Baddi, Tata Institute of Fundamental Research, Pune University, Maharashtra, India]

 

8 Stage LED VU Meter -  The circuit below uses two quad voltage comparators (LM339) to illuminate a series of 8 LEDs indicating volume level. Each of the 8 comparators is biased at increasing voltages set by the voltage divider so that the lower right LED comes on first when the input is about 400 millivolts or about 22 milliwatts peak in an 8 ohm system. The divider voltages are set so that each LED. . .  [Bill Bowden]

 

8x8 Animated LED Signboard -  The firmware supplied incurrent sourcecode archive is VERY BASIC. I do intend to draw more patterns. However, a vast workload coupled with possible emigration has put finished firmware on hold. Please do go ahead and build this circuit though supplied firmware is fully functional. You can have hours of fun designing your own patterns and effects!UsesPIC16F84. . .  [Lewin A.R.W. Edwards]

 

8x85 RGB POV Display. Part 1 -  Brads electronic projects This was my first attempt at a nice and colourful RGB LED POV Display. POV stands for persistence of vision. The circuit uses just 8 RGB LEDs which are mounted vertically and when spun horizontally it gives the illusion of. . .  [Designer's name not included]

 

8x85 RGB POV Display. Part 2 -  The drawing process is really quite simple. The pic microcontroller puts 00000000 00000000 on the eeproms address bus (selects the first address) This byte of info (at that address) is now placed on the data bus and all RED GREEN AND BLUE. . .  [Designer's name not included]

 

8x85 RGB POV Display. Part 3 -  Things to note in the source code: You can easily define how many frames of animation are in your animation loop by changing the total_frames variable to how ever many frames you have. The flying animation example has 178 frames. If you only have. . .  [Designer's name not included]

 

9 Second Digital Readout Countdown 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, . . .  [Bill Bowden]

 

9 Second LED Relay 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, . . .  [Bill Bowden]

 

94% Efficient 25W White LED Automotive Headlamp Driver -  The LT3956 is a DC/DC converter designed to operate as a constant-current source and constant-voltage regulator. It is ideally suited for driving high current LEDs. It features an internal low side N-channel power MOSFET rated for 84V at 3.3A and driven from an internal regulated 7. 15V supply. The fixed frequency, current-mode . . .  [Linear Technology App Note - , Jul 20th 2010]

 

9v Battery Voltage Monitor -  This circuit turns on a LED whenever the voltage of a standard 9v battery connected to the circuit drops below 7. 2 volts. It uses a LTC1440 comparator, which also contains a 1. 18v reference diode. In standby mode, the circuit draws only 4uA . . . [Circuit by Dave Johnson P.E.,  07/09/06]

 

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Light Emitting Diodes (LED) Circuits
LEDs:   #     A      B      C       D - E       F - H      I - K     L      M - O      P- R      S      T     U - V     W -Z


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


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