Temperature-to-frequency converter


Posted on Mar 4, 2013

The circuit exploits the fact that when fed from a constant current source, the forward voltage of a silicon diode varies with temperature in a reasonably linear way. Diode Dl and resistor R2 form a potential divider fed from the constant current source. As the temperature rises, the forward voltage of Dl falls tending to turn Ql off. The output voltage from Ql will thus rise, and this is used as the control voltage for the CMOS VCO


Temperature-to-frequency converter
Click here to download the full size of the above Circuit.

With the values shown, the device gave an increase of just under 3 Hz/°C (between 0 °C and 60 °C) giving a frequency of 470 Hz at 0 °C.




Leave Comment

characters left:

Related Circuits

  • New Circuits

    .

     


    Popular Circuits

    Simplest AVR programmer
    Car Controller using PIC16F870
    89c51 ds1820 based digital thermometer
    Computer Off Switch
    Battery Backups in Consumer Electronics



    Top