Digital temperature sensor

admin February 16, 2012 29 Comments

Description.

Here is a straight forward, yet effective digital temperature controller that can be used with temperature control systems.

The circuit uses IC LM 35 (IC3) to as the temperature sensor. The output of LM 35 is given to the IC ADC 0804 (IC4) which converts the analog output of the LM 35 to digital output. The ADC 0804 is a 8 bit ADC. Eight LED’s are connected to the output  of ADC to show the output logic. If needed the LED’s can be avoided and the output can be connected to any suitable external circuit like temperature controller etc. A 5V fixed voltage regulator based on 7805 (IC1) powers the circuit. Another variable voltage regulator based on LM317 (IC2) is used to provide the reference voltage to the ADC 0804.

Circuit diagram with Parts list. 

Digital Temperature Sensor Circuit

Digital Temperature Sensor Circuit

Notes. 

  • POT R10 can be used to adjust the scale factor of the ADC.The reference voltage at pin  7 of ADC0804 should be 2.5 V for full scale.
  • Assemble the digital circuit project on a good quality PCB or common board.
  • If 1A bridge is not available make one with four 1N 4007 diodes.
Comments
  • FIKADU DIRIBA
    March 29, 2014

    thank u i am student pleace how i get the progeram of oil immersed distrubution transformer temperature sensor LM35 AND drive fan in micro c progeram

  • abc
    February 26, 2014

    need more description, working & applications

  • rajan
    September 30, 2013

    In ckt lc lm317 is used in which pin no1 is input but in datasheet pin no 3 is input.then what we take.

  • rajan
    September 3, 2013

    At output we get logic from eight led. But what is
    that logic.

  • sathi
    April 13, 2013

    i want connection for lm35 with adc0804 then that output given to encoder dow can i do this connection please help me

    • de rok
      May 13, 2014

      do u about this connection, please help me

  • January 5, 2013

    hallo,
    i want to make temperature controller so please send me how to interface adc 0804 with 8051 using LM 35,and also send its ALP prgramming.
    i’m very thankful to you.

  • raj kumar sharma
    December 16, 2012

    hi,
    i want to make aanalog to digital convertor with

    usb so i want your guide lines to make acircuit

    diagram .

  • jeni
    December 11, 2012

    Hello,plz someone help me,,am working on this circuit,,plz send me the simulation of this circuit on proteus,plz

  • sara
    October 19, 2012

    hi sir
    please heeeeeeeeelllllppppppppppp meeeeeeeeeee
    I also need the detail of the component used after the bridge (AC 230V) It has the symbol of a transformer but i am not sure at all. please help me out.
    Thanks

  • sara
    October 19, 2012

    I need the detail of the component used after the bridge (AC 230V) It has the symbol of a transformer but i am not sure at all. please help me out.
    Thanks

  • bala
    April 13, 2012

    are chuiyo logo circuit pahele check karo

    • jeni
      December 11, 2012

      Hello,please send me the simulation of this circuit on Proteus,plz plz plz……….am very thankful to you

  • January 1, 2012

    Some neat info you have here, excellent work !!!

    • jeni
      December 11, 2012

      Hello,please send me the simulation of this circuit on Proteus,plz plz plz

  • Neerav
    November 12, 2011

    Hi i am actually using this circuit in my assignment. i am doing my circuit in Proteus. is there any need to connect pin8,10 and 20?
    I also need the detail of the component used after the bridge (AC 230V) It has the symbol of a transformer but i am not sure at all. please help me out.
    Thanks

  • yarra vijay
    October 23, 2011

    this site is very useful for learning of electronic basics

  • vysakh
    July 25, 2011

    i am sorry and never repeat this

  • seetharaman
    July 22, 2011

    Hi Shaban and Vysakh please communicate in english such that others can also use your valuable information.

  • vysakh
    July 21, 2011

    ﺎﻨﻫ ﻞﻀﻔﺑ ﻱﺃ ﻰﻟﺇ ﺝﺎﺘﺤﺗ ﻻ

  • shaban
    July 21, 2011

    واعاملين شكر جدا جداشكرا جزيلا لكل القائمين على الموقع

    • jeni
      December 11, 2012

      hello,plz help me,am working on this circuit,,plz send me the simulation of this circuit on proteus,,am very thank ful to you

  • shaban
    July 21, 2011

    واعاملين شكر جدا جداشكرا جزيلا لكل القائمين على الموقع

  • Abraham
    May 26, 2011

    please i need full description of the circuit. thanks

  • erf
    April 4, 2011

    plz put full description, I got problem in the simulation ?
    pin number 20 is connected to where? also 8 and 10 ? for pin number 7 need to connect to -2/5 or +2/5 ?
    i simulated in proteus but i can’t get the result plz describe it if is possible
    thanks alot

  • erfan
    April 4, 2011

    hi it seems to be a good circuit for ADC can you send us more information about circuit. thanks alot

  • rubana shaikh
    October 8, 2010

    requaire full discription of circuit diagram

  • baidya
    March 20, 2010

    i want to make this circuit can you help me…………….

  • chandrashekar
    March 30, 2009

    Its very good site for electronics persons and i like very much this site.

    Thanks for providing imformation

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