thermistor question

Discussion in 'General Electronics Chat' started by adamclark, Nov 19, 2013.

  1. adamclark

    Thread Starter Member

    Oct 4, 2013
    472
    6
    hello, I have a ttc104 ntc thermistor. I am currently building my power supply and have considered building a digital temp display with 7 segment displays. my psu is going to use 4 lm317 voltage regulators using a common heatsink. I was thinking of putting the ttc104 on the heatsink to measure the temp of my vr's.. My questions is would the ttc104 be able to measure the temp. like that? and what would I use to convert the analog to digital and drive the display? Im using icl7107's for the digital amp and voltages meters.. but I think that ic is geared more for volt and amp meters.
     
  2. Sensacell

    Well-Known Member

    Jun 19, 2012
    1,132
    267
    +Save yourself pain and suffering- use a modern temp sensor IC- they are linear, and output a predictable, known voltage. Thermistors require more analog wizardry, gain and offset circuits etc.
     
  3. #12

    Expert

    Nov 30, 2010
    16,343
    6,828
    Sensacell is talking about LM34 or LM35. They produce 10 millivolts per degree, C or F depending on the part number. Feed that directly to an ICL 7107 to get a temperature reading.
     
  4. MrChips

    Moderator

    Oct 2, 2009
    12,449
    3,365
    What about something like this?

    [​IMG]

    on ebay.
     
    #12 likes this.
  5. adamclark

    Thread Starter Member

    Oct 4, 2013
    472
    6
    that's pretty much the answer I needed.. thanks. how would I make that F instead of C??
     
  6. adamclark

    Thread Starter Member

    Oct 4, 2013
    472
    6
    thought about that route, but im using green 7 segments for the voltage and amps and I want everything to match and the experience of building it myself.
     
  7. #12

    Expert

    Nov 30, 2010
    16,343
    6,828
    The LM34 delivers F. Buy that one.
     
  8. adamclark

    Thread Starter Member

    Oct 4, 2013
    472
    6
    got it,, thanks.
     
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