Posted on Jun 12, 2012

A simple op amp and silicon diode are the heart of the temperature-to-voltage converter that will permit you to use an ordinary voltmeter-either analog or digital-to measure temperature. User adjustments make it possible for a reading of either 10 mV or 100 mV to represent 1 °F or C. Temperature sensor D1 is a 1N4148 silicon diode. It has a temperature coefficient of -2 mV/°C. Ul, a 741 op amp, is connected as a differential amplifier. A voltage divider consisting of R3 and Zener diode D2 provides a 6.2 V reference voltage. D2 is shunted by potentiometer R4, so that the offset can be adjusted to align the output voltage with either the Celsius or Falrrenheit scale, as desired.

Click here to download the full size of the above Circuit.

Gain control R2 is adjusted so the output of the op amp is in the scale or voltage range of the meter being used. R4, the offset adjust control, is then adjusted so the output voltage represents either degrees For C. The thermometer adapter can be calibrated by adjusting R4 while the probe sensor is at a known temperature.

Leave Comment

characters left:

New Circuits



Popular Circuits

Gas analyzer circuit
Home-Built Dye Laser
Simply analyse the temperature measurer cipher scheme based on DS18B20 and AT89C2051
Schematic Diagram UHF Wireless Video Audio Sender circuit andexplanation
Binary Up Counter Circuit with working animation and simulation video
TDA2030 35 watt audio amplifier circuit
Solar Cell and Photovoltaic Circuits
Field circuit diagram of the needle
555 practical DC stepless dimmer circuit diagram
It used to delay the monostable multivibrator circuit diagram of a continuous sequence