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Topic: Controlling the rotation of brushless motor by changing polarity (Read 23243 times) previous topic - next topic


After all that, you are probably better off just following an early suggestion:

Steve Greenfield AE7HD
Drawing Schematics: tinyurl.com/23mo9pf - tinyurl.com/o97ysyx - https://tinyurl.com/Technote8
Multitasking: forum.arduino.cc/index.php?topic=223286.0
gammon.com.au/blink - gammon.com.au/serial - gammon.com.au/interrupts


Hi polimorph,
I don't need to control the speed at this point.
What I need is to control the spinning direction of this motor by swapping of dc power polarity.
This schematic is my principle of achieving that control using my BLDC motor with an external driver.
When this schematic worked, I used a BLDC motor with a built in driver.
This time, my motor has an external driver and I want to make sure on arranging the connection between one of the anti-parallel diode end and the header pin.
The reason why I want to make sure on this thing is because I ended up frying my motor's driver.
I believe I should connect one of the anti-parallel diode end with #1 header pin like this(No shorting two pins in the header pin, only with one pin which is for F.
Tomorrow, I am going to order a new one and try again. Meanwhile, I wanted to make sure on connecting the circuit.


Hi polymorth
Unfortunately, I couldn't get any information about the circuit of this driver.
These are all I could receive from the motor supplier.
* Driver Spec.
* Connector Spec.
* Board

Which driver board - link or datasheet please.
[ I will NOT respond to personal messages, I WILL delete them, use the forum please ]


I couldn't get the datasheet. it wasn't available.
The site link is here.
The driver product name is SBDO-01


Well the best I could find on that site was the manual for the SBDSMA-02A which
is a similar controller, and has connector pinouts etc.
[ I will NOT respond to personal messages, I WILL delete them, use the forum please ]


Hi Mark T.
Thanks for your comment.
I ordered a new driver today which is SBDO-01(the same driver I used before and fried)and I will be getting it tomorrow.
I will test with that new driver using below connecting method and I will get back with result.
This time, I will pay extreme attention when connecting each wires.


May 13, 2014, 05:26 am Last Edit: May 13, 2014, 05:38 am by mingki Reason: 1
I did testing with new driver just now according to this link.
The driver seems to get fried again.

At first, I verified the motor's cw & ccw movement by applying 12V directly to this driver. It worked.
When the header pin is shorted, it rotates at cw. When the header pin is separated, it rotates at ccw.

After verifying this, I connected the driver with this schematic using above mentioned link and tried but the motor rotates only in ccw and never rotates at cw even though I apply 12v directly to the driver.

Do I need to use a certain anti parallel diode end to connect with driver's header pin like this?
Also should I connect 12v negative polarity with driver's header pin GND?

I must be able to control the spinning direction of my motor by changing the DC 12V power polarity to this driver.
Please please help me.  I would try anything.


I think that driver has opto coupled inputs?

You bridge-rectify the supply so the driver has correct polarity, but you also
need to conditionally drive the direction input via a single diode and resistor
so its activated only for one polarity of the supply I think...

[ I will NOT respond to personal messages, I WILL delete them, use the forum please ]

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