Possible to make a trapezodial motor run on sinusodial cont?

Pota

100 W
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May 15, 2017
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I have a Trapezodial Boma motor i would like to run on a sinusodial Controller. Is that possible?
The Controller is a Sabvoton SSC72150.
Can the hall be changed to fix this or what?
 
There is nothing trapezoidal inherent to a permanent magnet motor. In fact, any motor will run more efficiently on a sine wave.
If your motor has 3 big phase wires and 3 hall sensors (5 small wires), then it can be run fine by the Sabvoton. I think yours is the case.
If it only has 2 big wires then it is a DC motor with mechanical commutation and can not be run on brushless controllers.
 
miuan said:
If your motor has 3 phase wires and 3 hall sensors (5 small wires), then it can be run fine by the Sabvoton.
If it only has 2 wires then it is a DC motor with mechanical commutation and can not be run on brushless controllers.

Aha, but ive done all phase and hall combinations (36). And the Hall test still fails.
Ive also adjusted the hall angle(tho the sabvoton should autodetect this). Im running everything between 5 and 28current.
But since this is a Sinusodial Controller (sin wave) will it then also run a trapezodial motor like the Boma.
The motor is running but stuttering and not very delicate on the throttle. It goes from low rpm, and if i turn the throttle abit more it goes to max rpm.
 
Have you checked if the hall sensors output proper signal? All 3 of them should alternate between zero and 5 volts as you slowly turn the rotor.
Also, does the motor turn freely? There can be a short in the phase wiring or windings.
 
Yes. All 3 output between 0. and 5v. So that shouldent be an issue.
I dont know about phase wires. How can that be checked?
 
Pota said:
Yes. All 3 output between 0. and 5v. So that shouldent be an issue.
I dont know about phase wires. How can that be checked?

turn the rotor by hand. then connect any 2 out of 3 phase wires together. see if the motor gets harder to turn when phases are connected. repeat this 3 times to check every phase combination (A+B, A+C, B+C).
if you can't tell the difference between connected and disconnected, it means the phases are shorted to each other. This makes motor run hard and very hot.
It may however also be controller issue. There may be a short on the board or some mosfets may be blown. Have you got any other brushless controller to try the motor with?
 
Should i connect the battery, usb to pc and controller when performing the test?
No i have no other controller :(

But will the sabvoton be able to run trapezodial motor?
 
Pota said:
Should i connect the battery, usb to pc and controller when performing the test?
No i have no other controller :(

But will the sabvoton be able to run trapezodial motor?

You have to disconnect everything before performing the motor phase test. But when disconnecting the controller, do it one phase at a time and turn the motor by hand everytime to see if it will make the motor turn easier. That would indicate a short within the controller.
I repeat, there is nothing trapezoidal inherent to a permanent magnet motor. In fact, any motor will run more efficiently on a properly setup sine wave controller.
 
Aha. But will it work if there is no battery connected? I mean, how is it possible for the motor to get lighter or heavier to turn if there is no battery connected.

Thank you so much for helping me out btw :)
 
miuan said:
Pota said:
Should i connect the battery, usb to pc and controller when performing the test?
No i have no other controller :(

But will the sabvoton be able to run trapezodial motor?

You have to disconnect everything before performing the motor phase test. But when disconnecting the controller, do it one phase at a time and turn the motor by hand everytime to see if it will make the motor turn easier. That would indicate a short within the controller.
I repeat, there is nothing trapezoidal inherent to a permanent magnet motor. In fact, any motor will run more efficiently on a properly setup sine wave controller.

Okay ive done the tests and here are the results:

With battery connected AND disconnected to the controller
A + B = Hard to turn
A + C = Hard to turn
B + C = Hard to turn
Both way, disconnected and connected gave same results.

With battery connected.
A + B + C connected: Still as light as disconnected
Removed A: Still as light as disconnected (2 phases connected)
Removed B: Still as light as disconnected (1 phase connected)
Removed C: Still as light as disconnected (no phase connected)

Got the info you needed? :)

Here is a video of it running with all phases connected
[youtube]
https://youtu.be/CzVIDEvilOc[/youtube]
 
The point of that test is if it starts cogging (getting hard to turn), then there isn't a short in the windings​, but that sounds like it isn't the problem. You asked how it could change without a battery attached, as one winding goes past a magnet it generates a little pulse of electricity. When they're connected it feeds right back into the next winding, where it makes the opposite push on a magnet, making that cogging feel.
But it's a disconnected from the controller test.... And won't tell you anything about the functioning of the controller as far as I know.
 
He probably has noisy halls. This is a cheap motor after all. They won't have good halls in them. I bet that the hall signals are full of momentary spikes that are confusing the motor controller.
 
The Sabvoton has autodetect, don't try halls/phase combos, just hook up and run the detection to map the motor.

The sinewave controller makes a smoothly rotating field in the motor, instead of snapping it in 60 degree jumps. This works fine with a BLDC motor. It just operates it smoothly instead of hammering it.
 
Alan B said:
The Sabvoton has autodetect, don't try halls/phase combos, just hook up and run the detection to map the motor.

The sinewave controller makes a smoothly rotating field in the motor, instead of snapping it in 60 degree jumps. This works fine with a BLDC motor. It just operates it smoothly instead of hammering it.

THat's what should happen, but it's not. There is something wrong here and I'm wagering on the halls being flaky.
 
Ill buy these halls

Honeywell SS41
But there are many types:
SS411A
SS413A
SS495A1
SS413A
SS441A
SS41F

Since my Boma has crappy cheap halls :)

I bought SS411A since they have it here in Norway, will that work?

Sounds good?
 
Pota said:
I have a Trapezodial Boma motor i would like to run on a sinusodial Controller. Is that possible?
The Controller is a Sabvoton SSC72150.
Can the hall be changed to fix this or what?
Of course you can! You just won't experience the benefits of the sine controller, given that your motor's windings are constructed and oriented at an angle phi that results in a trapezoidal wave when repulsed/attracted by the magnets. No controller will ever change that. What you will gain though is more power efficiency especially at low speeds. Maybe also little battery life improvement, but that's just about it! Sorry


Sent from my iPad using Tapatalk
 
adaoud said:
Pota said:
I have a Trapezodial Boma motor i would like to run on a sinusodial Controller. Is that possible?
The Controller is a Sabvoton SSC72150.
Can the hall be changed to fix this or what?
Of course you can! You just won't experience the benefits of the sine controller, given that your motor's windings are constructed and oriented at an angle phi that results in a trapezoidal wave when repulsed/attracted by the magnets. No controller will ever change that. What you will gain though is more power efficiency especially at low speeds. Maybe also little battery life improvement, but that's just about it! Sorry
Sent from my iPad using Tapatalk

Also a more smooth run. Sinewave is quiet.
 
Think about this in a different way - the motor rotor is attracted to different positions by the current in each pair of the three wires. These positions are 60 degrees apart in a 3 wire motor. Now, instead of putting the full current through one pair of wires at a time, and using a "hard" transition by switching one wire suddenly, instead smoothly reduce the current on one wire while iincreasing the current on the previously unused wire. The third wire current remains constant through the "commutation". So the controller smoothly reduces one current while increasing the next wire's current, maintaining the same total current. Now the rotor smoothly moves from one position to the next, instead of trying to "snap" 60 degrees all at once.

The motor's rotation may not be completely smooth if the magnetic design is wrong, but it will always be smoother than a 60 degree "snap".
 
Sinusoidal controllers are better in general, but on an inrunner it's hard to tell the difference between sinusoidal or trapezoidal. I've tried both sin and trap on BOMA's, LightningRods small/big blocks and on AstroFlight 3220's and can't hear of feel a difference. I think you really hear/feel the difference on a hub motor the most. And yes no matter what controller you use, that won't fix the trapezoidal back EMF of the motor...if it is trapezoidal...it's going to stay trapezoidal.

Hey POTA...
Turn off the halls in your Sabvoton and unplug them from the controller. Try running the motor. Does it run smooth without the halls?
 
ElectricGod said:
Sinusoidal controllers are better in general, but on an inrunner it's hard to tell the difference between sinusoidal or trapezoidal. I've tried both sin and trap on BOMA's, LightningRods small/big blocks and on AstroFlight 3220's and can't hear of feel a difference. I think you really hear/feel the difference on a hub motor the most. And yes no matter what controller you use, that won't fix the trapezoidal back EMF of the motor...if it is trapezoidal...it's going to stay trapezoidal.

Hey POTA...
Turn off the halls in your Sabvoton and unplug them from the controller. Try running the motor. Does it run smooth without the halls?

It wouldent run withouth the halls connected :S
 
Pota said:
ElectricGod said:
Sinusoidal controllers are better in general, but on an inrunner it's hard to tell the difference between sinusoidal or trapezoidal. I've tried both sin and trap on BOMA's, LightningRods small/big blocks and on AstroFlight 3220's and can't hear of feel a difference. I think you really hear/feel the difference on a hub motor the most. And yes no matter what controller you use, that won't fix the trapezoidal back EMF of the motor...if it is trapezoidal...it's going to stay trapezoidal.

Hey POTA...
Turn off the halls in your Sabvoton and unplug them from the controller. Try running the motor. Does it run smooth without the halls?

It wouldent run withouth the halls connected :S

There has to be a controller setting that turns off the halls as well.

That or we are delusional and the controller wont work at all without halls.
 
Pota said:
Ill buy these halls

Honeywell SS41
But there are many types:
SS411A
SS413A
SS495A1
SS413A
SS441A
SS41F

Since my Boma has crappy cheap halls :)

I bought SS411A since they have it here in Norway, will that work?

Sounds good?

I read somewhere that SS411A will not work as they are bi-polar and that you should use SS441A as they are unipolar. Anyone used SS443A successfully?
 
Trap BEMF motor should ideally have a trap output from controller for best efficiency.

It will work also with sine controllers, better or worse as the inductance always to some degree smoothes out the trap waveform towards sine form depending on the motor.

The general rule is motor and controller waveform should match.

SS411 is a great sensor for commutation use, it's not an issue that it is bipolar, why would it be since the rotor is bipolar. :D
 
miuan said:
There is nothing trapezoidal inherent to a permanent magnet motor. In fact, any motor will run more efficiently on a sine wave.

Nothing inherent? If bemf is trap then it's trap. It's an inherent characteristic of the motor and won't change. Current waveform from controller should match BEMF waveform - trap motor will not be run more efficient on a sine waveform, where do you get this from?
 
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