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How to monitor an actuator's feedback line from a microcontroller?

Discussion in 'Microcontrollers, Programming and IoT' started by markdire, Aug 31, 2018.

  1. markdire

    markdire

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    Aug 31, 2018
    [​IMG]

    the AG-020-B electric actuator is controlled from a microcontroller. Terminal 1 is connected to the DC PSU GND, Terminal 2 is connected to the +24VDC via a high side Power MOSFET(TPS22810) as shown below. This is for power saving.

    [​IMG]

    Low side MOSFET (AUIPS1021) Q5A and Q5B are used to control the opening/closing of the valve via terminal 3 and 4. The microcontroller I/O lines Valve_Ctrl_1a and Valve_Ctrl_1b provide a 3.3V signal.

    [​IMG]

    - Comments are welcome regarding the power and switching circuitry.

    - Any suggestion on how to monitor the feedback lines on terminal 8 and 10 from a microcontroller. A lamp is not suitable as the system will be enclosed in a box. I've come up with a relay as a possible solution but I would rather use discrete devices.

    [​IMG]
     
  2. WHONOES

    WHONOES

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    May 20, 2017
    How about a resistor to pin 8 with a 3.3V zener at the ground end with the junction of the two connected to your μP.
    Then a 1 would represent "open" and a 0 "closed". Same on pin 10. This assumes that the supply is dc not ac.
     
  3. markdire

    markdire

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    Aug 31, 2018
    Would you mind drawing a diagram?
     
  4. Bluejets

    Bluejets

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    578
    Oct 5, 2014
    Opto isolators.
    Open collector output.
     
  5. Alec_t

    Alec_t

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    642
    Jul 7, 2015
    How about
    SwitchStatusMonitor.PNG
    This assumes pins 7-10 are not connected to any other supply.
     
  6. markdire

    markdire

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    Aug 31, 2018
    How would you connect an Opto isolator to terminal 8 and the GPI?
     
  7. Bluejets

    Bluejets

    2,976
    578
    Oct 5, 2014
    Maybe like this....
     

    Attached Files:

    markdire likes this.
  8. WHONOES

    WHONOES

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    May 20, 2017
    Got around to doing your sketch. See attachment.
    Couldn't be simpler.
    Circuit is same for both.
     

    Attached Files:

  9. markdire

    markdire

    4
    0
    Aug 31, 2018
    There is no actual lamp in the real thing, it's just an example from the datasheet. And you have only access to one side of terminal 8 (customer wiring)
     
  10. WHONOES

    WHONOES

    564
    111
    May 20, 2017
    So, what voltages are there on pins 8 and 10?
     
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