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Dancing LEDs redcircuits - A LED sequencer, following the rhythm
of music or speech 9 Volt Battery-operated portable unit..... |
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Dark-activated LED or Lamp Flasher - This circuit adopts the
rather unusual Bowes/White emitter coupled multivibrator circuit. The
oscillation frequency is about 1Hz and is set by C1 value…..(electronic
design added 6/07) |
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Dark-Detecting LED Circuit - Here's a simple problem: "How do
you make an LED turn on when it gets dark?" You might call it the
"nightlight problem," but the same sort of question comes up in a lot of
familiar situations-- emergency lights, street lights, silly computer
keyboard backlights, and the list goes on. Solutions? Lots. The
time-honored tradition is to use a circuit with a CdS photoresistor,
sometimes called a photocell or LDR, for "light-dependent
resistor.".….(design added 11/08) |
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Data Multiplexer Adds Cursor to LED Display Driver - 03/30/95
EDN-Design Ideas..... EDN is migrating links. This link is not verified.
Google the "title" EDN for new link. |
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DC/DC Converter Drives LumiLEDs White LEDs from a Variety of Power Sources
- DN340 Design Notes (Linear Technology) (app note added 6/06)
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Decibel Meter - The circuit below responds to sound pressure levels from
about 60 to 70 dB. The sound is picked up by an 8 ohm speaker, amplified by a
transistor stage and one LM324 op-amp section. You can also use a dynamic microphone
but I found the speaker was more sensitive. The remaining 3 sections of the LM324 quad
op-amp are used as.... |
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Descrete Multistage Light Sequencer - The drawing below
illustrates a multistage light sequencer using descrete parts and no
integrated circuits. The idea is not new and I hear a similar circuit was
developed about 40 years ago using germanium transistors. The idea is to
connect the lights so that as one turns off it causes the next to turn on,
and so forth. This is accomplished with a large capacitor between each
stage that charges when a stage turns off and supplies base current to the
next transistor, thus turning it on. Any.....(circuit added 05/09)
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Dice - Press the push switch to 'throw' the dice: this makes the
circuit rapidly cycle through the dice numbers so that an effectively random
dice number is displayed by the LEDs when the push switch is released.…
[Designed by John Hewes] |
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Dice (nutchip) - A LED dice, bright, unbiased, and spectacular. The
display uses 7 LEDs to simulate the faces of a real dice…. (electronic design added
6/07) |
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Digital LED Ammeter - Measures current up to 10A with selected 100mA, 10mA
and 1mA resolutions. (circuit added 8/06) |
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Digital Led Chaser - This circuit uses digital circuits such as a
demultiplexer and a binary counter to create patterns of "moving" led lights.
This basic circuit is really cool when used in the dark or to light up a sign of some
sort, as it creates a cool pattern that catches the eye..... [Zaakid Mata at
kakinblogs@gmail.com] |
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Digital LED Clock & Timer - This is a combination digital 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 32 minute time
interval each day. Start time is set using 9 dip switches and ends 32 minutes later.
The 32 minute duration.... |
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Digital LED Voltmeter - Measures voltages up to 199.9V with 0.1V resolution.
(circuit added 8/06) |
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Displays: LED Matrix - Information for the Common Anode LED Matrix Display
for SA04-11EWA, NFM-12882BEG-11, LEDM88RG (Updated 7/03/2006) |
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Dot/Bar Display Driver - The LM3915 is a monolithic integrated circuit that
senses analog voltage levels and drives ten LEDs, LCDs or vacuum fluorescent displays,
providing a logarithmic (added 07/07/07) |
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Drive 12 LEDs with one I/O line - 4-Feb-10 Issue of EDN Use a binary
counter to generate LED-lighting codes..... [Design Idea by Charaf Laissoub, Maisons
Alfort, France] |
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Drive a blue LED from a 3V battery - 15-Feb-07 Issue of EDN Two 1.5V
cells and a few components can light a blue LED..... [Design Idea by Sergi Sánchez,
Federal Signal Vama SA, Vilassar de Dalt, Spain; Edited by Brad Thompson and Fran
Granville] |
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Drive High Intensity White LEDs Efficiently using the PIC16C781 - Microchip
Application Note Published 17-Jul-02 (app note added 2/06) |
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Driver Thermally Compensates LED - 09/02/99 EDN-Design Ideas.....Optical
power of popular types of LEDs decreases with temperature. Optical-power measurements
into a typical multimode fiber at 62.5/125 ?m for a GCA 1A194 LED indicate a
temperature coefficient of approximately -0.4%/°C. In bipolar analog drivers for
short- and medium-distance fiber links [Design Idea by Andrzej Wolczko, University of
Mining and Metallurgy, Krakow, Poland] |
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Driving A Bi-Coloured LED - Some 3-leaded LEDs produce red and green.
This circuit alternately flashes a red/green bi-coloured LED |
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Driving LEDs in Battery Operated Applications: Controlling Brightness Power
Efficiently - Maxim Application Note #1804.....[App Note] |
Driving RGB LED using LP3936 Lighting Management System - National
Semiconductor Application Note 1293 The LP3936 Lighting Management IC contains a
versatile RGB Driver. It needs only a few register writes through the
serial interface to start and maintain complex blinking patterns thus reducing
microcontroller loading. (app note added 2/06) |
Driving RGB LEDs using Lp3933 Lighting Management System - National
Semiconductor Application Note 1291 The LP3933 Back/Funlight Management IC contains
two versatile RGB LED Drivers. It needs only a few register
writes through the serial interface to start and maintain complex blinking patterns
thus reducing microcontroller loading. (app note added 2/06) |
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Driving White LEDs - The 555 is capable of sinking and sourcing up to 200mA,
but it gets very hot when doing this on a 12v supply. The following circuit
shows the maximum number of white LEDs that can be realistically driven from a 555 and
we have limited the total current to about 130mA as each LED is designed to pass about
17mA to 22mA maximum. A white LED drops a characteristic 3.2v to 3.6v and this means
only 3 LEDs can be placed in series. |
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Dual Full Function White LED Step-Up Converter with Built-In Schottky Diodes -
Linear Technology LT3466.....[App Note] |
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Dual LED Flasher - Some useful circuits using the LM555 IC. Scroll to
find the Dual Led Flasher circuit (11/06) |
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Dual White LED Driver Features Integrated Switches & Schottky Diodes in 3mm × 3mm Dfn
Package - DN1010 Design Notes (Linear Technology) (app note
added 1/06) |
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Dual-Display with LED Driver with 3/2x Switched Capacitor Boost - National
Semiconductor Application Note LM2796 February 2004.....[App Note] |
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Dynamo-Powered LED Headlight & Tail Light for your Bicycle - Three classes
of LED light systems are presented: Basic, Medium Power and High Power, a tip
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Economical Circuit Drives White LEDs - 11/23/00 EDN-Design Ideas.....Newly
available white LEDs are replacing CCFLs (cold-cathode fluorescent lamps] in handheld
applications using a back-lit LCD. These applications include PDAs (personal digital
assistants], digital cameras, and cellular telephones, to name a few. Advantages of
white LEDs over CCFLs include longer life, higher efficiency, and significantly lower
operating voltages..... [Design Idea by Eddy Wells, Texas Instruments] |
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Efficient LED power supply has battery backup - 04/08/10 Issue of EDN
Power three to six LEDs from an ac- or dc-power source and charge a backup battery.…
[Design Idea by Zhihong Yu, Juno Lighting Group, Des Plaines, IL] |
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Efficiently Powering Nine White LEDs with the MCP1650 - Microchip
Application Note Published 3-Aug-04 (app note added 2/06) |
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Eight LEDs Random Flasher - This project uses a 4026 counter and display
driver IC to flash eight LEDs in an apparently random manner. It can be used to create
a display of your choice.… [Designed by John Hewes] |
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Emergency Light - A simple circuit that activates a light when the power is
out. A version with a lightbulb and another with white LED light included….
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Expandable 16 Stage LED Sequencer - The circuit below uses a hex Schmitt
Trigger inverter (74HC14) and two 8 bit Serial-In/Parallel-Out shift registers
(74HCT164 or 74HC164) to sequence 16 LEDs. The circuit can be expanded to greater
lengths by cascading additional shift registers and connecting the 8th output (pin 13)
to the data input (pin 1) of the succeeding stage. A Schmitt trigger oscillator
(74HC14 pin 1 and 2) produces the clock signal for the shift registers, the rate being
approximately 1/RC. Two additional Schmitt Trigger stages are used to reset and load
the registers when power is turned on. Timing is not critical,..... [Bill Bowden] |
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Extending Battery Life with the TPS61040 White Light LED Driver - TI
Application Note (added 2/06) |
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