Temperature-to-frequency converter


Posted on Nov 5, 2012

Al's positive input is biased by the thermocouple. Al's output drives a crude V — F converter, comprised of the 74C04 inverters and associated components. Each V — F output pulse causes a fixed quantity of charge to be dispensed into the 1 µ¥ capacitor from the 100 pF capacitor via the LT1043 switch. The larger capacitor integrates the packets of charge, producing a dc voltage at Al's negative input. Al's output forces the V-* F converter to run at whatever frequency is required to balance the amplifier's inputs.


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

This feedback action eliminates drift and nonlinearities in the V — F converter as an error item and the output frequency is solely a function of the dc conditions at Al's inputs. The 3300 pF capacitor forms a dominant response pole at Al, stabilizing the loop.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

Motor Speed control with optocoupler
Complete SS Laser Power Supply Schematics
What do I need for a basic RF circuit
Vibration Detector Circuit
60 watt bass amplifier



Top