Position: Index > Linear >

Linear temperature-to-frequency

2017-03-18 20:24  
Declaration:We aim to transmit more information by carrying articles . We will delete it soon, if we are involved in the problems of article content ,copyright or other problems.


This circuit provides a linear increase of frequency of 10 Hz/?°C over 0-100 ?°C and can thus be used with logic systems, including microprocessors. Temperature probes Ql Vbe changes 2 mV/?°C. This transistor is incorporated in a constant current source circuit. Thus, a current proportional to temperature will be available to charge Cl. The circuit is powered via the temperature stable reference voltage supplied by the 741
Linear temperature-to-frequency

Comparator ICl is used as a Schmitt trigger whose output is used to discharge Cl via Dl. To calibrate the circuit Ql is immersed in boiling distilled water and PR1 adjusted to give 1 kHz output. The prototype was found to be accurate to within 0 ?°C.



Reprinted Url Of This Article:
http://www.next.gr/meter-counter/thermometer-circuits/linear-temperature-to-frequency-transconducer-l13039.html