Feedback of my schematic/diagram

Discussion in 'Homework Help' started by MrBear, Jul 31, 2013.

  1. MrBear

    Thread Starter New Member

    Dec 3, 2012
    19
    0
    Hi Forum.

    I have started to draw a schematic of my project but think i might have been lost somewhere in between a schematic and a wiring diagram (not 100% sure what the difference is).
    I have a system composed of a motor, motor-controller, an Arduino (micro controller), a bridge amplifier and a simple circuit. I am a ME so electronics are a new world (of fun) for me. If you feel like giving me some feedback of the schematics/wiring diagram i would be pleased.
     
  2. LDC3

    Active Member

    Apr 27, 2013
    920
    160
    The 7805 will get very hot. Why not use the 24V supply to make your voltage divider?
    I'm guessing that one of the resistors (R4-R7) is going to be replaced by a sensor.
     
  3. wayneh

    Expert

    Sep 9, 2010
    12,154
    3,061
    With a 20k load? I don't think so. It's just acting as a voltage reference, as far as I can tell. Might have missed something.
     
  4. LDC3

    Active Member

    Apr 27, 2013
    920
    160
    I thought the MPU was powered by 5V, so the 7805 was supplying more than just the voltage divider.
     
  5. WBahn

    Moderator

    Mar 31, 2012
    17,777
    4,805
    But then using a 24V supply directly isn't an option.

    Is port A6/SCL of the Arduino an A2D input? It would seem that the output of the bridge amplifier is likely an analog signal that is being biased to the midpoint. If it is a digital signal, then why the bias to the midpoint and not just a pullup, assuming that is even needed?

    As tot he difference between a schematic and a wiring diagram, the two have a lot in common and sometimes the same diagram serves both rolls. The main difference is usually the intent as far was what information is conveyed. A schematic generally focuses on revealing how and why a system works or on what it accomplishes. A wiring diagram is primarily focused on how the system is put together. A wiring diagram will incluse a lot of other information, such as connector pin identifiers, wire colors, wiring harness information, that is not relevant to knowing how a system works and may leave out information about what the signals are on the pins of a component which aren't relevant (directly) in being able to hook it up. Also, when you have multiple pages, the decision of what goes on what page in a schematic is based on the information carries by the signals on the connectors, whereas in a wiring diagram is it often based more on the physical routing of the signals, often using the connectors as page ports.
     
  6. MrBear

    Thread Starter New Member

    Dec 3, 2012
    19
    0
    Hi.
    Thank you all for the reply. I am sorry i haven't had the chance to reply before now.

    The resistors r4 -r7 are a configured in a Wheatstone bridge and are therefore used to measure strain. I have placed them on a shaft so i can monitor the torque in the shaft. The bridge amplifier outputs a bipolar +-10V but the arduino can only read 0-5V, thats the reason for the resistors r1-r3. The 7805C does not get hot.

    A force is measured on the shaft, the signal is converted into something the Arduino can read (0-5V) and then the arduino sends PWM to the OSMC which controls the torque of a brushed DC-motor.
     
  7. MrBear

    Thread Starter New Member

    Dec 3, 2012
    19
    0
    Hi Again.

    I have now made some few adjustments on my schematic. I have been reading up on decoupling Caps and as far as i can read, i need some;-).

    From the material i have read, i would place the following (please correct or add):

    1) One over each motor, as close to the motor as i can.
    2) at both Mot+ (don't know if that is necessary if i have the motorcap).

    Thats it!

    How does that sound?

    One more thing. I have to power the hallsensor, and the 2 pots - is that best done with the microcontroller or is there a reason to do it from one more voltage regulator?

    Thank you again for all your help.

    MrBear
     
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