HEAT SENSOR image


Posted on Feb 7, 2014

This simple circuit senses heat from electronic devices and gives warning alarm. It is an ideal add on circuit to monitor heat in CD players, Amplifiers etc. The circuit uses 14 stage ripple free binary counter IC CD 4060. It has an internal oscillator and its frequency is set by C1, VR2 and R2. Reset pin 12 of IC determines its working. When pin1


HEAT SENSOR image
Click here to download the full size of the above Circuit.

2 is high, IC remains off and turns on when pin 12 becomes low. Variable resistor along with the NTC Thermister forms a potential divider to set the voltage level at pin12. When the temperature is normal, resistance of Thermister will be high so that IC1 remains off. When the temperature exceeds a level set by VR1, IC1 starts oscillating and Red LED blinks. After few seconds buzzer sounds indicating that temperature inside the device is increasing. So that the device can be switched off immediately to prevent damage. Enclose the circuit inside the device with thermister close to the heat generating area. Power to the circuit can be obtained from the device.




Leave Comment

characters left:

Related Circuits

  • New Circuits

    .

     


    Popular Circuits

    60 Watt switching Power supply
    4.5Mhz notch filter
    PID PROJECT
    74C164 8 bit shift register work as a heart for car LED light sequencer
    Hum Filter Remove AC Line Noise Pre Amp Circuit for Hi-Fi Amplifier Audio Systems
    frequency multiplier for lf
    FM Radio jammer
    TDA9813T TDA9813T VIF-PLL With QSS-IF And Dual FM-PLL Demodulator
    Egg Timer



    Top