This looks dead-simple and very compelling!
I just have one question:
If I wanted to output sinusoidal waveform (example: for my ironless assemblies) IÃ¢â‚¬â„¢d need to use another device rather than the MC3033, yes?
Well done. KF
texaspyro wrote:Put a ceramic on the FET driver chip (and maybe a tantalum). Wouldn't hurt to put a couple more ceramics on the phase lines.
Jeremy Harris wrote: <snip>
This chip only does 6 step (so-called trapezoidal) commutation, which is hard-wired in and driven by the standard Hall sensor outputs. It can't be changed to run sinusoidal PWM variation with electrical angle, as it doesn't have either a position encoder input or anything other than the hard-wired 6 step commutation table.
Sinusoidal commutation ideally needs a way of measuring absolute rotor angle more accurately than just three Hall sensors will allow. One way to do this is to fit an encoder on to the shaft to provide the additional angular resolution needed. It is possible to interpolate between Hall sensor pulses to derive an estimate of the required angular position, which works OK at steady speeds, but this method has significant errors if the motor has a low rotational inertia and is capable of changing speed rapidly.
Kingfish wrote:Thank you for the explanation; greatly appreciated. I have some more questions but they are OT so I shall ponder and start a new thread so as not to steal any more thunder from your most excellent effort:
The design of your board is truly a clean layout. Quite inspiring, friend.
HAL9000v2.0 wrote:Great design, Jeremy.
The laser printer method is great!!!! This is missing reason to buy new printer. Never heard of it before. I did all kind of etching masks but this seams super simple, Thanks for sharing.
Alan B wrote:Nice job, Jeremy!
What software do you use for layout?
Alan B wrote:When I was making double sided PCBs at home I drilled a couple of small holes to use as fiducials to align the sides. These are drilled after one side's resist is applied and before the other side is done. The second side can then be aligned on those holes.
Jeremy Harris wrote:The driver chips have local decoupling on the 12V Vcc lines, you can see the 100uF electrolytics on the board layout, I just missed them off the schematic. There's one 0.1uF ceramic on this line already, but I guess I could add some locally right at the driver, if they're needed, or maybe swap out the electrolytics for some affordable low voltage tantalums.
vanilla ice wrote:Nice! An inkjet printer and a clothes iron.. gotta love it.
I'm very curious how that alt throttle mode is going to feel. Throttle feel is oft ignored but very important imo.
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