Electronic thermometer(1)

Published:2011/5/10 21:31:00 Author:Nicole | Keyword: electronic thermometer | From:SeekIC

This electronic thermometer adopts temperature sensor to detect temperature, the measured temperature is displayed by LED. The temperature measuring range is 35-40T, the temperature resolution is 0.5℃(it can display 10 temperature values such as 35.5℃、36℃、36.5C…39℃、39.5℃、40℃). The working principle of this circuit This electronic thermometer circuit is composed of temperature measurement amplifier circuit, comparison amplifier circuit and temperature indication circuit, it is shown in the figure 9-132. The temperature measurement amplifier circuit is made of temperature sensor IC1, operational amplifier IC2(Nl、N2) internal N1 and resistors R1, R2. The comparison amplifier circuit is composed of resistors R3-R6, potentiometers RPl、RP2 and IC2 internal operational amplifier N2. The temperature indication circuit consists of LED display drive IC3, resistors R7-R19, LED VLl-VLlO and capacitors C1, C2. If the measured people's temperature is 36℃, VLl and VL2 turn on, and VL3-VLlO off; if the temperature is 37℃, then VLl-VL4 turn on, VL5-VLlO off; if the temperature is 38℃, then VLl-VL6 turn on, VL7-VLlO off, and so on.



Reprinted Url Of This Article:
http://www.seekic.com/circuit_diagram/Sensor_Circuit/Electronic_thermometer1.html

Print this Page | Comments | Reading(3)