circuit to display pressure ,ph,light & control temperature

Discussion in 'The Projects Forum' started by mahesh_e63, Sep 28, 2010.

  1. mahesh_e63

    Thread Starter New Member

    Sep 27, 2010
    hi guys im new to this forum ....
    this is my first post in this forum...
    so plz give me good response by solving my simple doubt.
    my qustion is that i want to design a circuit using sensors which is capable of displaying light,ph,pressure & it shold be able to control temprature....
    so plz i request u to give me the design for above design project...
    plz help me as soon as posssible..
  2. mahesh_e63

    Thread Starter New Member

    Sep 27, 2010
    yaar iska solution koi to batao bahot din se kisine reply he nahi kya isme?????/
  3. wayneh


    Sep 9, 2010
    You can get temperature using an analog IC such as LM35 and a voltmeter to display output. I've been working on a temperature controller myself lately and have posted a near-complete circuit that might help you.

    I believe there are similar ICs for pressure but I've never tried one. By "light", do you mean intensity, for instance with sunlight as 100% and moonlight as 5% or whatever? For that you could use the output of a cheap landscape solar light across a load resistor and again display the voltage as your output. Not necessarily linear response.

    pH is very difficult, since you need to accurately measure in the mV range at very high impedance, and you need to adjust zero and scale (ie. calibrate the meter). I'd recommend a cheap used meter but I suppose you could roll your own if you're good at op-amp circuit design.
  4. marshallf3

    Well-Known Member

    Jul 26, 2010
    Pressure sensors can be inexpensive or highly expensive depending on the level at which they need to be used. Sometimes you can pick up surplus ones at a fairly reasonable cost.

    Why don't you outline exactly what this is supposed to be &/or do as a device?