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Safety Flasher - This circuit alternately flashes two high-brightness LEDs as a
safety measure during jogging or walking. The LED’s can be mounted on clothing or a
belt. The circuit draws a precisely controlled 10mA in order to conserve battery life.
Also, the battery voltage can drop to the LED voltage plus about .5 volts before there
is a noticeable..... Designed by Andrew R. Morris (added 09/05) |
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Scheme provides High Side Current sensing for White LED Drivers - 02/19/04 EDN-Design
Ideas: White LEDs find wide use in backlighting color-LCD screens in most portable
devices, such as cellular phones, PDAs, and MP3 players. Multiple LEDs often connect
in series to ensure that the same current flows through every LED. To forward-bias
these LEDs, a voltage of 10 to 16V.....(design idea added 1/05) |
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Senses & displays ambient light intensity - 11/09/06 EDN-Design Ideas: LED doubles
as photosensor and visual indicator of ambient-light intensity.....(design idea added
05/07) |
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Sequential LED Flasher - for 10 LEDs (Tony van Roon's electronic design added
4/02) |
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Serial Comms to LED Driver - (circuit / schematic added 2/03) |
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Series Connected Voltage Boost Circuit for a Battery Operated LED Lantern - 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...(schematic / circuit added 6/07) |
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Series White LED Driver - National Semiconductor Application Note LM3590 November
2003 (app note added 02/05) |
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Seven Component Regulated LED Lamp - (electronic design added 9/02) |
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Signal Processor Adds LED Display - 06/06/96 EDN-Design Ideas: Designers using the
Texas Instruments TSS400, a versatile 4-bit sensor-signal processor, may find the
circuit in Figure 1 useful as a replacement for, or an adjunct to, the IC's built-in
display capabilities.....(design idea added 6/05) |
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Simple LED flasher circuits - By simple, I mean that these circuits only flash one
or two LEDs. This is opposed to the light chaser circuits that can flash four or more.
Of course, the simplest LED flasher is simply to use a flashing LED. The problem with
that approach is you have no control over the flash rate, but it does have its use for
eye catching displays for selling stuff. The circuits below give you that
control,.....(added 10/05) |
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Simple Logic Probe uses Bicolor LED - 03/13/98 EDN Ideas: ….(design idea added
09/09) |
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Simple Photodetector Circuit - I´ve designed this simple circuit to test a
photodetector. I got the detector from an old 5 1/4" disk drive. If you can get one,
you will find two photodetectorts: one is used to sense the density (double density or
high density).... (schematice added 6/07) |
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Simple single cell white LED driver uses improvised transformer - 02/15/07 EDN-Design
Ideas: Minimal component-count circuit boosts a single cell's voltage to light an
LED.....(design idea added 02/07) |
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Simple two transistor circuit lights LEDs - 04/09/09 EDN-Design Ideas: (design
idea added 08/09) |
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Simplest LED Flasher circuit - (schematic / circuit added 6/07) |
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Simplified PC Connections for Gpib Instruments - Aligent Application Note
(app note added 4/08) |
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Simplified White LED Flasher Operates from One Cell - 05/26/05 EDN-Design Ideas:
The white-LED flasher in Figure 1 offers an alternative approach to a previously
published idea (Reference 1). Targeting use in portable appliances and products
powered by a single cell, this circuit flashes an LED to provide a highly visible
warning signal—for example,.....(design idea added 1/06) |
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Single & Two Cell White LED Drivers Without Inductors - The operating voltage of
white LEDs coupled with my emotional need for low cost for a given function, motivates
me to make LED drivers suitable for battery operated lanterns that can run from a
small number of cells. White and Ultraviolet LEDs....(schematic / circuit added 6/07) |
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Single Cell Flashes White LED - 12/11/03 EDN-Design Ideas: Many portable
appliances and other products that must operate from a single cell are restricted to
working at very low voltages. It is thus difficult to drive white LEDs that typically
have a forward voltage of 3 to 5V. The ability to flash the LED with a supply voltage
as low as 1V presents additional complications.....(design idea added 1/05) |
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Single Cell Lights Any LED - 07/05/01 EDN-Design Ideas: The circuit in Figure 1
allows you to light any type of LED from a single cell whose voltage ranges from 1 to
1.5V. This range accommodates alkaline, carbon-zinc, NiCd, or NiMH single cells. The
circuit's principal application is in LED-based flashlights, such as a red LED in an
astronomer's flashlight, which doesn't interfere with night vision.....(design idea
added 1/05) |
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Single Cell TPS61041 LED Driver Slva136.Htm, 1 Kb - TI Application Note
(added 2/06) |
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Single FET Controls 2nd LED Array in Switchmode LED Backlight - Maxim APP1871:
Feb03,2003 / (app note added 5/08) -A design in which the display is backlit (or
frontlit) for extended periods needs an efficient circuit that drives the LEDs with a
controlled current, and eliminates the wasted power associated with current-limiting
resistors. A switch-mode boost design that regulates current instead of voltage
accomplishes this purpose. |
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Single FET Controls LED Array - 04/12/01 EDN-Design Ideas: (design idea added
11/05) |
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Single LED flasher - Flashing a LED should not require a complex circuit. A
reverse biased transistor does the job in a nice way. Circuit "a" flashes the LED
twice a second: changing the capacitor and/or the resistor will change the frequency,
also the supply voltage.... (added 9/07) |
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Single LED Indicates Two Power States - 12/05/96 EDN-Design Ideas:
-Uses a single bicolor LED to indicate both power-on and blown-fuse
conditions.....(design idea added 6/03) |
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Single Port Pin Drives Dual Led - 10/13/05 EDN -Design Ideas
Single-line LED driving can be versatile.....(design idea added 11/05) |
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Sky Writer - We have seen many projects using a set of LEDs to produce words "in
the air," but none have the feature of an inertia switch to provide registration. One
of the biggest problems with waving a display to produce writing in the air is
maintaining the same position for the letters as it is moved back and forth. If the
words are jumping or shown in reverse, they are difficult to read....(electronic
schematic added 05/08) |
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Solar Charged LED Utility Light - ….(circuit design added 03/08) |
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Special Lighting - experiments with white LEDs (added 4/02) |
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Stealth mode LED controls itself - 05/25/06 EDN-Design Ideas: High-efficiency LED
doubles as a light detector.....(design idea added 11/06) |
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Step-Down Conversion Concept for a PWM-Mode Boost Converter - TI Application Note
(added 2/06) |
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Strange LED Sequencer - This bizzare but simple PWM circuit fades from LED to LED.
This deceptively simple sequencer actually pulse width modulates the LEDs as it fades
from one LED to the next. Bulbs will last much longer when driven in this gentle
manner; add FETs or transistors to the outputs if you wish to drive bulbs. You can
reconfigure the capacitors....(added 2/05) |
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Super Bright 3v Powered LED Flasher - I have posted several kinds of LED flashers
over the years. This is yet one more flasher, designed to flash any high power
LED of any color. It hits the LED with a 25ms 250ma pulse once every 2 seconds.
This works out to an average current about 3ma. It is powered by any 3v source.
I suggest two AA cells but a single 3v lithium coin type cell will also work.
With fresh AA cells, the light should flash for about two weeks. The light flash
is very intense and is perfect for any attention getting night time application.....
….(designed by David A. Johnson) |
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Super Simple Flasher - Scroll down to find this circuits. Here is a simple
flasher circuit that uses no resistors! However, it relies on leakage in the base of
the PNP germanium transistor and only some will work; be prepared to try a few. If you
add a 100k resistor from the base to the collector of the PNP, the circuit will work
with most germanium transistors …..(added 07/07/07) |
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Switching regulator efficiently controls white LED current - 04/27/06 EDN-Design
Ideas: Circuit has 93% efficiency and beats 64% efficiency of series resistor
approach.....(design idea added 11/06) |
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Synchronous Buck/Boost High Power White LED Driver - Linear Technology LT3453 (app
note added 02/05) |
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Synchronous Step-Up DC/DC Converter for White LED Application - National
Semiconductor Application Note LM3500 February 05 (app note added 02/05) |
