Project: Flasher circuit

Thread Starter

amey

Joined Nov 4, 2007
1
NOVEMBER 2002 ELECTRONICS FOR YOU
ASHOK K. DOCTOR
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 flashing beacon
that uses well-known regulator IC LM317T.
As LM317T regulator can deliver more than
1 amp. A small 12V, 10W bulb with a
high-quality reflector can serve as a good
visible blinker.

A 12-15V, 1A DC supply is connected
to the input pin of the IC. A 12V, 10W
bulb and a combination of resistors and
capacitors are connected between the output
pin and ADJ pin of the IC as shown in
S.C. DWIVEDI
the figure. The IC is provided
with an aluminium
heat-sink to dissipate the
heat generated while delivering
full current. Since the
IC has an inbuilt switch-on
current limiter, it extends
the bulb life.
For the shown values
of resistors and capacitors,
the bulb flashes at approximately
4 cycles per second.
The number of flashes depends
on the charge-discharge
time of the capacitors.
Different values of resistors and capacitors
can be used to increase or decrease the number of flashes.
This circuit costs around Rs 50.-
 

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Bernard

Joined Aug 7, 2008
5,353
Just left another Thread " How many LED 's can run from 12V. Here about 150, 50strings of 3 ea.+ 50 150Ω resistors. Nice circuit.
 

jj_alukkas

Joined Jan 8, 2009
753
Why dont you try using an automobile turn indicator relay??? It can run heavy loads and needs nothing more than a single component.. No heatsinks and no mess.. just 2 terminals on a box
 
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