Hi there -
I recently was given a 12v, 7-pin brushless motor without much data. I believe it is a "dual channel phase-tracking encoder" - but I'm struggling a bit to understand what that all means. I tend to understand things better once I have some code and schematics in front of me!
I was hoping to get some advice for how to safely attempt to drive it with an Arduino, not knowing entirely what I'm dealing with.
Thanks!
For a DIY project, you really, really need a data sheet for the motor/encoder. Otherwise, look for the matching driver, and its documentation.
Model and code numbers printed on the motor casing will help with web searches.
HI @jremington
I was able to find this: eBay link -
Which seems to be the same item.. but I am unable to find a corresponding datasheet.
Is there a cautious, sensible way to proceed, though? I would like to make use of something, rather than garbage.
Yes, of course! Buy a motor that meets your requirements, and has a complete data sheet with clear operating instructions and example wiring diagrams, from a reputable supplier that supports their products.
The motor you linked evidently has a built in driver, and there appears to be barely enough information on the ebay product page to get that motor working, if you have basic understanding of motor control, and can get the designated wired connector, along with a clear description of what each wire does.
Looks very cool. It would be nice to have a Pinot but I would try putting 12v into the red and black and see if anything happens.
If that does make the motor run one of the other colors connected to black might reverse the direction. Using the servo driver from your Arduino you might be able to control the speed on another pin.
Searching around I found a similar motor with this color code:
Red +12
Black ground
Green frame ground
Yellow fwd/rev
Blue pwm speed
White brake
Does that help ?
Great - this seems to get me into the ballpark. Powering the device with 12v to Red and GRD to black makes sense to me. I will try that and see if anything runs.
I'm a little less certain about the anticipated signal for the other wires, though. I'm assuming some kind of voltage applied to Blue can reverse the direction - and that White is expecting some kind of PWM signal to modify speed* - but I'm not sure what "SP" means.
FG1 and FG2 are also a little obscure to me - but as page suggests there is a "two channel pulse signal output" - I suspect that might be the White and Grey wires.
I was thinking since people on this forum probably work with so many motors, some of this stuff would be common knowledge - but I guess this will be more difficult than I expected.
*Re:PWM - I'm assuming sending a low-voltage PWM from an Arduino would not do much at this pin, though I could start there. Is there a general-purpose way of amplifying a PWM signal that would make sense for this motor, based on what has been revealed so far?
Looking again at the eBay page:
The speed can be adjusted when the PWM port has input voltage of 4.6V~0.8V, the motor will start work at 4.6V and will work with full speed at 0.8V, users can also use the PWM signal to control the speed,
Recommended PWM frequency: 10KHz
This makes me think that the PWM input is expecting a steady DC voltage that it converts to a PWM frequency.. but then it seems to suggest inputting a frequency of 10KHz. I would be curious if anyone had a intuitive read of this information.
That ebay link has some model numbers, like "3630-37-14", and plugging them back into google gives this ebay link: Brushless DC Gear Motor DC 12V BLDC Gear Motor PWM CW/CCW Dual Channel Pulse | eBay which has this wire ID diagram:
That might be a place to start.
The pwm signal will be a square wave at around 10khz where the duty cycle represents the desired speed.
FG means frame ground and can be ignored. A logic level high signal means forward and a logic low is reverse.
The CHA and CHB part of the CHA(FG1) and CHB(FG2) might mean encoder A/B channels.
Or possibly the pins might be alternate FG1/FG2 Frequency Generator signals as per https://www.hitachi-power-semiconductor-device.co.jp/en/products/ic/pdf/PDE-ECN30216S-2.pdf if the motor happens to be equipped with that feature.
Hi all -
Thank you for helping with this.
I plugged in the 12v this evening (12v to red wire, grd to black wire). No movement just yet.
Then I plugged in 2.5v, using a 5v power supply over a voltage divider, to the white wire. This started the motor moving.
The question I would have is what the best way of giving the motor a voltage would be. Could I simply take the 12v power, put that through another voltage divider, and send it to the white wire? Does the white wire need a separate voltage source? Should I be using a voltage regulator?
The speed control is PWM. Connect it to a PWM pin on the Arduino and set PWM values according to desired speed (using analogWrite(x)).
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