Schematic

Week 4:

We started working on our schematic. For us it was first time with designing tool like Altium Designer and we had a lot of problems navigating in the program. Our first approach is shown below:

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This approach is far from optimal, but we started. Questions which we faced on that stage was:

How physically we want to provide power to the cicruit? How we want to measure speed of the motor and which in reality is how we obtain feedback voltage from motor to our regulator? How to deal with different supply voltages +18 for amplifiers in PID parts and +12 for motor?

Week 5:

We changed a little bit our design after consultation with our tutor. He suggested us that we should check if amplifiers can work with lower voltage and that we can measure voltage of motor using encoder or we can mount an led and measure time elapsed between every rotation. We decided to add standard 2-pin header to part related to motor. After corrections our schematic looks like below:

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Questions which left: how to obtain -12 voltage for amplifiers? How do we want to provide supply voltage to the PCB?

Week 6:

We solved problem with -12V using inverting amplifier circiut. As previous we added header pin for supply voltage and after discusion we decided to put potentiometer on set point voltage. This way we can adjust reference voltage which corresponds with speed of the motor. We had some lectures on electronics in meantime and we added decoupling capacitors, but our system won’t be working on high frequencies, so that we could just skip them. Now our schematics looks like shown below:

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Week 7:
Our mentor suggested to add functionality for our project which is possibility to turn off/on I and D parts. We added them and started working on layout. Final scshematic is presented below: