> On Feb 5, 2017, at 12:02 AM, 'woody stanford' via BeagleBoard > <[email protected]> wrote: > > OK, here is my best guess. I'll need to breadboard it out to get it working. > It basically glues some reference designs (off of the Internet...beware lol) > with some approaches that I've used for years together. I have to admit that > I'm a little shaky in the MOSFET area, but I know I can get a design like > this to work with some fiddling. > > I would recommend to someone trying to get this to work to breadboard a > SINGLE CHANNEL of it, maybe using the PWM on the BBB PRU to output signal to > the optoisolator stage of the circuit. Or if you can find a solid > pre-programmed PWM PIC out there (and there are quite a few smaller operators > that sell ASIC-type preprogrammed PIC's with some operation or function on > them...for example, hobby servo control is a nice starter design to mess > with) to drive your isolated power electronics with some kind of > off-the-shelf motor. > > *** Can you treat a propeller like a resistor? *** > > An interesting idea I had was to treat my motor-propeller combination as a > true electrical component, looking at it from a power transfer perspective. > What I mean by this is there are equations out there that model perfectly a > propeller's force and a propeller's effective power transfer to the air it > pushes, that I suspect that you can equate the electrical equations involved > with the mechanical POWER ones for propellers (and the electromechanical > setup of the motors used to drive them). An idea. But it would allow you to > fully model a drone's power systems in a way I don't think heretofore done. > > OK here we talk about how to power the 3 voltage zones. You'll notice that > I've chosen holistically to do it with dumb voltage regulators and this is a > product of kinesthetically "knowing" the current draw on each of the zones. > The BBB is probably a little more of a power hog than people give it credit > for, though I can feel the heat coming off it to be not much, so I'm sure it > can be driven off of VR. The PIC the same...very energy efficient so a 7405 > will keep my workload low. Also added are some pulldown resistors (on the > "optional" network) because I'm afraid my MOSFET's are going to "float" (they > call it) and have the BBB to PIC issue worked out (you can float PIC lines > because they have built in pulldown resistors). > > Again, untested. I don't use this term loosely. There is no guarantee that > this circuit will even work at this stage. Well, it won’t work because the diode of the optocoupler is connected incorrectly.
Regards, John > > > <https://lh3.googleusercontent.com/-bsKGGuckDZI/WJbcHZX_WKI/AAAAAAAAAF4/_fYnYOdEk-gN1hVCGdXQc7mPDSl549BTgCLcB/s1600/drone_mosfet2.png> > > > > On Monday, January 30, 2017 at 6:19:30 PM UTC-7, woody stanford wrote: > I posted the remote control for this in Software, but I put a bunch of > hardware in it so I thought I'd post it here. > > https://groups.google.com/forum/#!category-topic/beagleboard/software/evSIUcuWfUY > > <https://groups.google.com/forum/#!category-topic/beagleboard/software/evSIUcuWfUY> > > -- > For more options, visit http://beagleboard.org/discuss > <http://beagleboard.org/discuss> > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected] > <mailto:[email protected]>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/beagleboard/eea20b90-eda4-474e-8ab6-515f8689cd8f%40googlegroups.com > > <https://groups.google.com/d/msgid/beagleboard/eea20b90-eda4-474e-8ab6-515f8689cd8f%40googlegroups.com?utm_medium=email&utm_source=footer>. > For more options, visit https://groups.google.com/d/optout > <https://groups.google.com/d/optout>. -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/EE51A195-BE28-40EA-B61E-DD709763D444%40gmail.com. For more options, visit https://groups.google.com/d/optout.
