Speed Control of Brushless Motors

Hope our electronic friends can help. I am conversant with the basic principals of low (24 V DC) motors using the cheap units available on ebay for speed control of brushed motors.

What I need now is information to control and direction and speed of brushless motors, again low voltage. Can anyone help in advising how to solve this problem without too much technical input and using cheap components.

What's wrong with eBay, plenty of brush less controllers for r/c fraternity and cheap to boot. A simple servo tester will drive these boards giving you potentiometer control of speed. For more sophistication you could use an arduino board. 

Regards

Howard

Driver ICs are available to drive low power motors and can feed transistors to provide any level of voltage or current required. The ICs have control pins for speed and direction. A knowledge of electronics and an ability to solder would be required to use one.

If you could say "I have this motor that I want to control" then either here on an electronics forum or E-Bay could provide an answer.

Frank

From what I can find out the drive circuitry is effectively replacing a commutator which means the coils driven by this need to be stationary. The switching frequency controls speed and phase will set direction. A simple view.

I did try playing around with a relatively low rpm per volt model aircraft motor and driver but didn't stick a scope on it to see what was going on. I found that the speed regulation didn't seem to be too good but suspect that was the controller. I had wondered about using one to drive a tool post spindle powered by a redundant power supply intended for use on a server. There is info on getting some of these to run out if a server - some pins have to be shorted etc. One problem is the size of leads needed as the power goes up.

There is plenty of info on the web such as

**LINK**

I'd guess there will be info on using an arduino to do the basic drive about as well.

John

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What about the control for an E-Bike, a lot of them use brushless motors 200 to 500Watt +.

Ian S C

If you want to know the theory behind the control of BLDC motors, with and without a position sensor, check out these two links. Even if you don't want to build a controller from scratch, understanding the principle will help:

www.atmel.com/images/doc8138.pdf - sensor control

www.atmel.com/images/doc8192.pdf - sensorless control (the usual method)

(you need to read the first one to get the basic theory before reading the second one).

Neil

Edited By Neil Wyatt on 26/10/2015 18:35:37

Have used this controller for 12 & 24v motors Brushed and brushless - Am using 4 to control the motors in 5” gauge loco. Also on lathe feed screw.

DCM DC MOTOR CONTROLLER MODULE - Farnell

You will need to type into search engine as does not work as link

my problem is lack of knowledge about electronics. The E bike controllers bristle with all sorts of input leads. I just want to be able to plug in a motor to a controller to a power supply.

Can anyone make it that simple please ?