voltage differential temp sensors

Discussion in 'General Electronics Chat' started by aac9876, Aug 23, 2009.

  1. aac9876

    Thread Starter Active Member

    Dec 9, 2006
    124
    0
    I'm looking for a cheap simple temp sensor chip that measures temp by a known voltage difference from a standard... between 80F to 150F if possible,dry environment.. the kind you hook to a meter and check the voltage difference without any other stuff.. and a source mail order and price??
    thanks
     
  2. mik3

    Senior Member

    Feb 4, 2008
    4,846
    63
    You can use a digital thermometer like the DS1820 which can measure temperatures between -67F and 257F.
     
  3. rjenkins

    AAC Fanatic!

    Nov 6, 2005
    1,015
    69
    Look at things like the LM335 - that works like a temperature controlled voltage reference or zener. Feed 1mA bias current and read the voltage across it.

    The voltage drop is 10mV per degree kelvin, so freezing (273K = 0C) is 2.73V, boiling(373K = 100C) is 3.73V.

    Also look at the LM34 & LM35, they are three terminal with separate power & output, calibrated 10mV per degree F or per degree C.
     
  4. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    A thermistor might be the absolutely simplest solution - http://en.wikipedia.org/wiki/Thermistor

    You will have to look up the resistance reading on a chart to determine the correct temperature because they are not linear in response.
     
  5. aac9876

    Thread Starter Active Member

    Dec 9, 2006
    124
    0
  6. ELECTRONERD

    Senior Member

    May 26, 2009
    1,146
    16
    I believe that a thermocouple sensor measures the temperature based on the voltage difference on the two other ternimals. You could use a comparator or instrumentation amp to equate this difference.
     
Loading...