Quote:
Originally Posted by solma
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.
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The IGBT always has a 1.8-2 V junction drop, so they only make sense in higher voltage designs. If you drive your motor at 12 V, then the IGBT will lose 2/12 = 17% efficiency right off the top, before switching losses. At 24 V, it's 8%, so still quite a bit.
Yes, MOSFETs switch slower, but as of around 2005 it is not really an issue below say 10 kHz, and at low battery voltages they have much lower voltage drops than IGBT. This is why MOSFETs are still used in so many ESCs. Switching noise will most likely not be an issue, especially if you drive at 20 kHz, and there is no point in going to higher frequencies for this project.
The bottom line is that you should let the design dictate the details. If you want to drive at 70 V, then maybe an IGBT looks pretty good, but if you are driving at 20-30V, you can use automotive grade MOSFETs and get higher efficiencies.