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How to start BLDC motor only 1 turn with max torque and power
mgwalker95:
The most efficient way to drive a linear motor like this is going to be a control algorithm that will measure the position of the shaft and use sinusoidal control, But you can use Trap control if you want it easier to control and dont care about noise. the position of the shaft shouldn't be hard to measure because all you need is 3 hall sensors like a regular BLDC motor or you can use one hall sensor that reads the magnetic field as a analog value.
Here is a good beginners guide from digikey:https://www.digikey.com/en/articles/how-to-power-and-control-brushless-dc-motors
One big difference between a regular BLDC motor and a "BLDC motor" like this is that this motor can reach an end where the motor must stop, so your control algorithm must take this into account.
cmcraeslo:
--- Quote from: Benta on July 29, 2020, 07:53:06 pm ---Don't mushroom us when asking questions. It decreases your popularity to far below zero.
--- End quote ---
It was not my intention to mislead. It was just the fact that this is indeed a BLDC motor, just laid out differently. I was merely explaining what the setup and the reason behind the "1 turn" motor be.
cmcraeslo:
--- Quote from: duak on July 30, 2020, 12:33:54 am ---If the point is to accelerate as quickly as possible with the simplest driver and smoothness is not important, it might be possible to adapt a Sensorless BLDC driver that reads the Back EMF voltage off the windings as they pass over the magnets. Here's some of many links available: https://www.nxp.com/docs/en/brochure/BBCNTRLBLDCART.pdf
https://www.st.com/resource/en/application_note/dm00072008-sensorless-sixstep-bldc-commutation-stmicroelectronics.pdf
--- End quote ---
Point is to accelerate as fast as possible, position and smoothness is not important as it will be stopped mechanically (and obviously controlled by the electronics). It is to replace pneumatic actuator.
There's no Back EMF voltage when motor is stalled so I'm worried i'll get unwanted forward/backward moves when starting the commutation.
cmcraeslo:
--- Quote from: jbb on July 29, 2020, 10:27:47 pm ---Yeah, it makes no sense to deliberately ask about the wrong thing.
I’m sure there’s research on that kind of motor. Maybe it’s a Linear Permanent Magnet motor? Looks like the kind of thing that might be used for machinery - are special things like accurate positioning and low vibration needed?
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I'm trying to replace pneumatic actuator (on/off), so no, position and and smoothness is not important. Only speed and power. It will be stopped mechanically. End switch will be available to stop it in the software.
Berni:
--- Quote from: cmcraeslo on July 30, 2020, 04:58:18 am ---
--- Quote from: Benta on July 29, 2020, 07:53:06 pm ---Don't mushroom us when asking questions. It decreases your popularity to far below zero.
--- End quote ---
It was not my intention to mislead. It was just the fact that this is indeed a BLDC motor, just laid out differently. I was merely explaining what the setup and the reason behind the "1 turn" motor be.
--- End quote ---
Asking an incomplete cut down question on forums is the best way of getting answers that go in the complete wrong direction. Quite often the person asking the question then finds out 3 pages of discussion later that what he is trying to do is the wrong solution for the problem to begin with.
If this is some super secret project where nobody must know what you are doing then figure it out yourself. If you ask people for free engineering advice at least put in the work to describe the whole problem accurately. People here are friendly and happy to help, but not asking the question correctly just wastes everyones time.
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