Project: Flasher circuit

Discussion in 'The Completed Projects Collection' started by amey, Nov 4, 2007.

  1. amey

    Thread Starter New Member

    Nov 4, 2007
    1
    0
    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.-
     
  2. cumesoftware

    Senior Member

    Apr 27, 2007
    1,330
    10
    So, you are using the "adj" pin to give some positive feedback, behaving the LM317 like an oscillator?
     
  3. SICKNESS1

    New Member

    Nov 16, 2007
    1
    0
    Thanks You Very Much
     
  4. ohm_5000

    New Member

    Dec 22, 2007
    1
    0
    thank you very much
     
  5. narced

    New Member

    Dec 22, 2007
    3
    0
    thanks a lot!
     
  6. Legi0nare

    New Member

    Jul 27, 2008
    1
    0
    Thnx for the circuit
    :)
     
  7. tallht

    New Member

    Jul 30, 2008
    3
    0
    thanks a lot
     
  8. Giggabyte

    Member

    Sep 19, 2008
    15
    0
    this is good .
     
  9. u.chinonso

    New Member

    Sep 29, 2008
    2
    0
    this is good
     
  10. Bernard

    AAC Fanatic!

    Aug 7, 2008
    4,172
    397
    Just left another Thread " How many LED 's can run from 12V. Here about 150, 50strings of 3 ea.+ 50 150Ω resistors. Nice circuit.
     
  11. jj_alukkas

    Well-Known Member

    Jan 8, 2009
    751
    5
    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
     
  12. vinay soni

    New Member

    Feb 16, 2009
    1
    0
    nice project
     
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