Heat Detector Circuit

Discussion in 'The Projects Forum' started by vick5821, Apr 14, 2012.

  1. vick5821

    Thread Starter Member

    Jan 27, 2012
    54
    0
  2. chrisw1990

    Active Member

    Oct 22, 2011
    543
    41
    okk, why not draw what you have set up? ignore that picture, and draw what you have actually built? also post pictures.. that diagram when your finished.. and do you have an oscilloscope?
     
  3. paulktreg

    Distinguished Member

    Jun 2, 2008
    611
    120
    What sort of thermistor have you use?
     
  4. #12

    Expert

    Nov 30, 2010
    16,276
    6,788
    The schematic posted looks valid.
    If reset (pin 4) = high, then run.


    Likely error is the thermistor vs 470 ohms as noted by paulktreg
     
  5. vick5821

    Thread Starter Member

    Jan 27, 2012
    54
    0
    I am now using LDR...How can I able to increase the sensitivity of the LDR? Now I have to make it really dark to activate the alarm instead a light dark room :(

    Thank you
     
  6. chrisw1990

    Active Member

    Oct 22, 2011
    543
    41
    you need to adjust the lower resistor, so that the transistor comes on when its suitably dark.. just trial and error. you can use maths but trial and errors more fun:D
     
Loading...