| Electronics > Projects, Designs, and Technical Stuff |
| pinout puzzle on big BLDC drivers (repurposed automotive motors) |
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| mtraven:
--- Quote ---The measured phase resistance of the coils means nothing. --- End quote --- well shit that's a useful piece of information. Would measuring the inductance be of any use to me? --- Quote ---A EPAS system in order to provide the maximum fidelity must provide torque assistance to the driver..... --- End quote --- while I very much appreciate your detailed explanation, all I was really trying to say was the column mounted, wormgear style assist systems get away with a smaller motor because of the huge reduction in a worm gear. I just didn't want people to think it was one of those smaller ones. and that is enough on that. --- Quote ---You won't get any info from Hella regarding the driver IC, as that is a proprietry automotive chipset, so you'd have to sign an NDA with them before they will release it to you. --- End quote --- I didn't even ask for a schematic, just a pinout and what the pins were expecting...but they didn't even bother send a "no" ...seems a bit unprofessional if ya ask me. --- Quote ---Realistically, peak motor currents of around 100 amps are used, perhaps as high as 150 amps for a few seconds, but the resistance of a lead acid battery starts to become limiting, ie the supply voltage falls with increasing current, limiting the power you can pull from the battery to a couple of kW at peak. --- End quote --- so based on that, how much current should my mosfets be rated for? 150? 200? your comment about a limited supply from a battery got me thinking, what the hell kind of power supply and I gonna need to run this thing. I made a spot welder a few years back that supplies 1200-1500amps, but that's just a few seconds..thats going to need some serious consideration. On a related note, I have just learned one of the methods for controlling speed (maybe the only?) is to regulate the supply voltage feeding the mosfets. Do I have that right? So that is another big ass mosfet(or set of mosfets) correct? I had just assumed the gates of the Fets would be driven by a variable input that would determine speed. I am sure there is a reason they don't do it that way, any idea what that reason is? |
| james_s:
Something I forgot to mention, there is an open source firmware called BLHeli, and another one the name of which escapes me. Those and the associated hardware notes are a treasure trove of information on driving BLDC motors. |
| oPossum:
--- Quote from: james_s on December 02, 2019, 04:41:21 am ---Something I forgot to mention, there is an open source firmware called BLHeli, and another one the name of which escapes me. Those and the associated hardware notes are a treasure trove of information on driving BLDC motors. --- End quote --- SimonK is one of the others. I think they both are derived from an earlier firmware. edit: Derived from Bernhard Konze's tp-18a firmware There is also the more comprehensive VESC firmware (unrelated to the previous). |
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