Fluid level meter version 2


Posted on Feb 5, 2014

IC4 is a counter/oscillator combination and is the key element in the circuit. The oscillator outputs its AC signal on pin 7. This signal is lead (through voltage divider R3/R4) to pin 3 of IC5 (multiplexer IC) which is used as an input. The same signal is also lead to the rectifier/demodulator build up with D1/R1/R5. The resulting rectified signal is compared (with IC2, an opamp) with a constant voltage. If a selected electrode is under water, there will be an extra load on the AC signal, which causes the output of the demodulator to drop a little bit. The comparator will react by changing its output level. All this takes a fraction of a second because the multiplexer will only handle one electrode at a time by connecting the AC signal to the selected electrode.


Fluid level meter version 2
Click here to download the full size of the above Circuit.




Leave Comment

characters left:

Related Circuits

  • New Circuits

    .

     


    Popular Circuits

    Video title generator
    British Police Car Siren circuit diagram
    The Second W9VES
    Nuar
    Two-Channel PC Based Oscilloscope USB
    Light Gate With Counter Using 555 And 4033
    TDA7056 audio amplifier circuit diagram electronic project
    Using the Panasonic WM61A as a Measurement Microphone
    Netduino Building the Circuit on a Breadboard
    Adjustable Voltage motor controller
    Controlling Motor Starting



    Top