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LDmicro Forum - Control of motor by MOSFET

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Control of motor by MOSFET (by hassan)
Is it possible to help from the experts? I want to control the motor of a forward and backward direction at a speed of 10 hz via two keys.
Please help. Six control outputs and the coil for clarification.
Wed Oct 27 2021, 10:09:08, download attachment 3 Phase Schematics.pdf
(no subject) (by MGP)
Read this:

I can assure you that it will be very difficult to get that working.
Wed Oct 27 2021, 16:49:44
(no subject) (by Ziggy)
The schematic is OK.
The problem is to implement an algorithm to get the motor to run with reasonable torque.
I assume the motor is a brushless, sensorless DC motor.

Such motors typically require a predefined starting point along with back emf sensing.
At any point in time only two of the three windings are energised in a predefined sequence.
Initially the motor is brought into a known position by energising only two predetermined windings.
This is followed by the next pair of windings being energised so that the rotor starts to move ( there are six valid combinations of energising windings for a full 360 degree turn of the shaft.)
Back emf builds up with shaft speed and depending on how well the BEMF sensing circuitry works the motor may be switched from a slow ... very slow acceleration regime untill BEMF sensing works ok to full synchronised switching , synchronised to motor rotor speed.

Starting and direction changes are a problem without hall sensors.
as MGP pointed out.. a hard thing to tune and get to run well .
Fri Oct 29 2021, 04:04:55
(no subject) (by hassan)
Thank you very much for the clarification
Wed Nov 3 2021, 14:07:00
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