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

    Ir-Controlled Soldering Station
    Battery-Charging Indicator For Mains Adaptor
    Wireless IR Headphones circuit
    Lightning Detector Circuit
    High-Voltage Regulator With Short Circuit Protection
    Precision QRP Transmitter
    555 Composition with Watchdog circuit
    A709 a simple differential amplifier circuit diagram
    CS51227 by the output of 28V 5A DC power supply circuit
    FET high input impedance wideband amplifiers