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:

New Circuits

.

 


Popular Circuits

6v to 12v converter
Attendance counter
Complementary AC power switching
Fire Alarm Circuit Using 555 IC
AVR ISP ScoketBoard
converter r2elhc600a 10v
Audio Voice-Over Circuit PCB
mosfets tester
Timer circuit
ictd92
Piezoelectric Sound
Isolation transformer and low-pass filter wiring



Top