How to Build Toxic Gas Detector and Alarm Circuit with TGS813


Posted on Feb 7, 2014

The danger always exists, when the fuel gases such as propane or gas are confined to a small area. The alarm of toxic gases figs. 1-45 utilizes a tin-oxide-semiconductor. A coil of thin wire heated by a battery 12 V via IC1 and IC2, which pulses the voltage to the coil of the sensor, saving a significant amount of energy. Diode Zener Dl provides a


How to Build Toxic Gas Detector and Alarm Circuit with TGS813
Click here to download the full size of the above Circuit.

constant voltage to the filament coil sensor. resistance of the sensor reduces the sensor is exposed to toxic gases such as hydrogen, carbon Carbon monoxide and propane. To reduce the resistance of the sensor, the SCR gate voltage increases. When the gate threshold voltage is reached, the SCR fires and a buzzer alarm is activated. Once activated, the bell and the switch S1 should be used to reset the alarm. Since the sensor has a good deal of thermal inertia, S1 must be off or open for about three or four minutes after the initial activation, allowing the sensor to stabilize, thus avoiding false alarms. R7 sensitivity control set to the desired value, before the activation of SCR. The toxic gas alarm is sensitive to less than 100 ppm of carbon monoxide. This alarm is useful for simple gas boats, sheds and cabins. You could save a life. Some of the companies listed in the Appendix to offer plans and kits for various toxic gas sensors.




Leave Comment

characters left:

Related Circuits

  • New Circuits

    .

     


    Popular Circuits

    Field Strength Meter
    LED operates as light sensor
    Unijunction metronome
    Audio Alarm Circuit
    simple bus level-shift / I2C mosfet level converter Fairchild BSS138
    stereo balance indicator
    fet preamp
    TDA2555 Dual Tv Sound Demodulator Circuits - Nxp Semiconductors
    Lets to build many VU Meter circuits with LM3914
    Arduino ATmega328 Hardcore
    Simple RF Signal Generator
    20W 40-500kHz PA 01



    Top