Quote:
Originally Posted by ft_sjo
Is this more of a programming exercise than an automotive engineering one?
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I think people are sticking with what the know and we have a lot of programmers. I'm focused on hardware and have parts on the way to start building a prototype. After all programming does nothing without something to test it on.
Quote:
Originally Posted by solma
I think you should go simple on this, first, closed loopback system need stability and there nothing stable in a motor going from stop to high rev with non-linear torque force on it, that why even in slower system like an engine they use mapping that run open loop in fast changing condition.
Second, I think, if you are afraid of restriction, you shoud use a bypass system, it does not take away any energy from the engine when you will not be using your supercharger.
Third, be careful about technical spec on component, MOSfet are not good for most motor control appication Ton-Toff are normally to long(so they heat up to much), use IGBT its like MOSfet but design for this kind of application.
I would go with a simple 8 bit PIC familly microcontroler(microchip), they simple to code, programmer dont cost much, and are stable in a wide range of temp(summer heat in car can get pretty high), oh and do not use a crystal for the clock use an oscillator, vibration will kill the crystal(made this error once and you do not want for full uncontrolable power on the elec. motor).
I least that a few thing I would think about if I would go into that kind of project.
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I'm in total agreement. The closer this is to a stand alone system to start with the better. I like the idea of a bypass, but I'm getting hung up on what to use for the valve.
Two bypass options as I see it:
1. An electrically controlled valve. Using a throttle body is what first comes to mind.
I don't personally like this. It becomes another active component that adds to complexity.
2. A spring loaded valve that is is held open when there is lower pressure on the engine side relative to the intake side. As soon as the compressor kicks in and there is higher pressure on the intake side the valve is forced closed.
Some sequential bi-turbos use this type of valve but I'll be darned if I can find where I can buy one.