I have a electric power steering pump that uses a can bus control. It is a brushless dc motor with four windings. The speed of the motor is controlled by using PWM I can get it to run, but only at a low speed, 1300 rpm (the range is 1300 - 4500). I would like to be able to control it with either a variable foot pedal or if I can get the rpm to 2800-3000 that would work. Any thoughts or ideas would be appreciated.

 

I have a electric power steering pump that uses a can bus control ... The speed of the motor is controlled by using PWM...

Well, which is it? Do you want a PWM motor controller (widely available cheap online) or a CANbus controller?

 

Well, which is it? Do you want a PWM motor controller (widely available cheap online) or a CANbus controller?

I would like a CANbus controller, but do not know how I could control this unit(software comands). so a pwm motor controller for a four winding brushless if something is available

 

PWM is used over automotive CANbus for heater motor and other automotive controls. I am not all that familiar with CANbus but believe it is similar to Modbus, which I have used.
What PWM controller are you using? Or is it a AC synchronous controller with varying frequency?
Max.

 

PWM is used over automotive CANbus for heater motor and other automotive controls. I am not all that familiar with CANbus but believe it is similar to Modbus, which I have used.
What PWM controller are you using? Or is it a AC synchronous controller with varying frequency?
Max.

I have no controller, when you connect 12v + and - to the power wires and add a run signal 12v + the unit runs at a low rpm. There are 5 wires on the unit (12v + 12v - two CANbus wires and a run signal wire). The unit has a control module built in to it, so as the control module receives the CANbus input the motor will speed up or slow down. I was hoping to remove the control module and use PWM to control the motor, but can not find a controller that will handle four rotor windings. I want to use this pump on a race truck, and need the most pump pressure at low speed when loading on a trailer or driving in a parking area. Thanks

 

You probably need a 2Φ BLDC controller or 4 phase controller should work also.
It may be difficult to find off the shelf.
Max.

 

BLDC motors do not run on just "PWM".
They need a controller to switch the currents through the coils in sequence to run.
This video exlains it...

A BLDC controller is quite different to a PWM DC motor controller.
Some motors have Hall sensors to read the rotor position to tell the controller when to switch the phases, and the controller does PWM the currents to control the speed. You may be able to find if the board uses a separate CAN CPU and motor controller and feed a signal to the controller but that may not work.
If you can find the CAN commands, maybe an Arduino pressed into service to send the CAN commands could work. I don't know if a motor controller used for a big quad copter would be ok.
Or maybe something like this?
http://www.ebay.com.au/itm/12V-36-5...789122?hash=item2a6d625c42:g:sF0AAOSwtnpXmw6S

 

BLDC motors do not run on just "PWM".
They need a controller to switch the currents through the coils in sequence to run.
This video exlains it...

A BLDC controller is quite different to a PWM DC motor controller.
Some motors have Hall sensors to read the rotor position to tell the controller when to switch the phases, and the controller does PWM the currents to control the speed. You may be able to find if the board uses a separate CAN CPU and motor controller and feed a signal to the controller but that may not work.
If you can find the CAN commands, maybe an Arduino pressed into service to send the CAN commands could work. I don't know if a motor controller used for a big quad copter would be ok.
Or maybe something like this?
http://www.ebay.com.au/itm/12V-36-5...789122?hash=item2a6d625c42:g:sF0AAOSwtnpXmw6S

Yes this motor has hall effect sensors. The item on ebay that you referenced is for a three winding motor, the unit that I have has four windings. That is the problem that I have. I need a BLDC controller for a motor with four windings.

 

As in #6, you may find it difficult to find an off the shelf 2Φ controller for this particular motor, 3 winding BLDC are the much more common now.
Max.

 

Have a look at this, maybe it will give some ideas on how its done. www.lsicsi.com/pdfs/App_Notes/AN101.pdf

 

Have a look at this, maybe it will give some ideas on how its done. www.lsicsi.com/pdfs/App_Notes/AN101.pdf

So I should try the CANbus route, I found some code but am not sure how to put the hardware and software together. Any suggestions on a CANbus controller?