Wiring diagram/graphics for brushless motor full revolution

csm

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I am trying to cognitively get how the electricity is moving withing the circuits/coils of a brushless motor. So far I understand that brushless motors are 3 phase coil circuits. And some have hall effect sensors in between each of the phase coils and some are sensorless.

W-schms-3p-E.JPG


So I am thinking that for a three phase brushless motor, that there are 3 states at which the motor is moving electricity through the coils, and there are 3 states (combinations at which the hall effect sensors are at. The picture above is one of the best representations I have found for the wiring graphic of the (stator?).

So it seems that the coils each get electrified in the same direction in series and pulls the coil core to the permanent magnet that is closest to it of the opposite pole. And there is only on coil being electrified at a time. Correct? I realise this may be very novice beginner question for many of you. Ideally I will find an animation which shows the electricity flow through all the 3 phases of running the motor and another doing the same for the hall effect sensors in the motor. Seems like this is a primary thing to grasp cognitively before moving forward on doing diagnostics, modifications, hacking, etc.
 
brushless motor wiring diagram and phases for full revolution.jpgI am processing how the electricity is flowing and magnetic states of the components of a brushless motor for one revolution, including the stator coils and the hall effect sensors. This is as far as I have gotten. Is this correct? What am I missing?
 
on this page there is a graphic of how the brushless 3 phase motor is moving electricity through an entire loop. It appears that there are 6 different states that it cycles through until it begins to cycle through them again. http://diandeng.myweb.hinet.net/index_motor_3phase_6step.htm

I am not clear what the symbols mean. I suppost they represent the 3 wires coming from the stator coils (U, V, and W, with the - or + representing direction electricity? Is U, V, and W the standard letters used to represent the wires?) They are also using an apparent color code of black, gray, and red to indicate something. Not sure what it represents at this time.

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I think i am making progress in understanding the brushless motor technology. It seems that there are 6 steps that current flows through the wires untill it loops back and starts again through the 6 steps.

6624606-0-large.jpg
 
Here's an animation showing how the windings in a typical 12 slot, 14 magnet BLDC motor are powered in sequence by the controller:

LRK_in_action.gif


This site has a good explanation of the way commutation works with a 3 phase BLDC and is the one the above animation comes from: http://www.aerodesign.de/peter/2001/LRK350/Warum_dreht_er_so_eng.html
 
there is always TWO windings carrying current at one time, this gives a continuous circuit ( your picture of star and delta you can think of the current going in one end of a phase and coming out the end of another phase to make the circuit), the phase that is not being used has some current/voltage induced into it by it going past the magnets, that induced current/voltage is used by some sensorless controllers to perform the commutation ( switching of currents between phases).
so its always 2 on and one off at any time.
if you wanted an animation that also showed hall sensor firing order, things would get rather complex, I have some vague recollection of seeing such an animation.......somewhere.
 
"Jeremy" and "whatever"... thanks guys! That is the kind of stuff I have been looking for.

(continuing to study how brushless motors work)
 
Nehmo said:
All About Circuits, Brushless DC motor
Electric Motors and Generators
It sure is a cool animation. The 5 wires coming form the Halls are Power, Ground, and one for each Sensor.
On the animation page, the link to ResMed Motor Tech. leads to a ResMed that does something else. I don't get that part.

Thanks for the links. the "power" from all the hall sensors are connected together, all the "ground" wires coming from the hall sensors are connected together, and signal wire from each hall sensor seperately?
 
yup, each hall has three legs, an input ( positive 5v approx) an earth ( negative) and an output, since each hall has the same input and earth, they can all be connected, they are basically just powering the hall sensors. The output on each sensor is a signal that basically switches on/off as the magnets go past the hall sensors. So there are three signals used by the controller to switch the phases on/off ( via the hall sensor signals).
If you measure the hall sensor signal as a magnet goes past it, it gives a change in voltage, its usually something like 1volt and 5v ( they are the on/off signals), when checking if a hall sensor is working you measure this voltage change.
They dont completely switch off ( i.e. go to zero volts) usually its around 1volt or so. The controller picks up this change in voltage of the output wire........its the change in voltage on the output signal thats important for the controller.
Also not all hall sensors are the same, some work on very tiny amounts of power some require more, ebike controllers you need to get the correct type of hall sensors I forget how much current they use its pretty small but you just cant throw any hall sensor in them.
 
whatever said:
yup, each hall has three legs, an input ( positive 5v approx) an earth ( negative) and an output, since each hall has the same input and earth, they can all be connected, they are basically just powering the hall sensors. The output on each sensor is a signal that basically switches on/off as the magnets go past the hall sensors. So there are three signals used by the controller to switch the phases on/off ( via the hall sensor signals).
If you measure the hall sensor signal as a magnet goes past it, it gives a change in voltage, its usually something like 1volt and 5v ( they are the on/off signals), when checking if a hall sensor is working you measure this voltage change.
They dont completely switch off ( i.e. go to zero volts) usually its around 1volt or so. The controller picks up this change in voltage of the output wire........its the change in voltage on the output signal thats important for the controller.
Also not all hall sensors are the same, some work on very tiny amounts of power some require more, ebike controllers you need to get the correct type of hall sensors I forget how much current they use its pretty small but you just cant throw any hall sensor in them.

Thanks "whatever".

In a way the hall sensor is kind of like a diode that has a switch in it that is controlled by magnetic fields?

So hall sensors consume about 1v of some small amount of current, even when in off position? I suppose this is one of the sources of drain on battery when controller is powered but motor is not being engaged to turn the motor?

the "output" leg of the sensor connects (after going through switch in controller) to the same wire/leg as the "ground" legs of the sensors?
 
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