DiscoverCircuits.com, has 30,000+ electronic
circuits, cross-referenced
into 500+ categories. We have searched the web to help you
find quick design ideas.
We make every effort to link to material posted by the designer.
Please let us if you would like us to link to or post your
design.
The contents &
graphics of Discovercircuits.com are copyright protected.
LINKING to Dave's circuits is permitted but DO NOT COPY any files to your WEB
SITE server
Super Bright 3v Powered LED
Flasher (April 22, 2009)
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.
The circuit uses a TLV3701, which is a nifty single low voltage, low current voltage
comparator from Texas Instruments. I configured the oscillator circuit to
produce the needed pulse signal. A charge pump circuit and an active current
limiting circuit supplies the LED with the needed drive signal, whose voltage can
exceed the 3v from the battery. This method insures that the typical 3.6v
required by most white LEDs can be produced.
Click on Drawing Below to view PDF version of Schematic
