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Electronics => Electronics => Topic started by: DanCF on December 11, 2006, 11:32:57 AM

Title: DC motor controller
Post by: DanCF on December 11, 2006, 11:32:57 AM
I just bought an MCU to control all my servos, however I also have an 18 amp motor (12V) which I would also like to control. I understand that there are cards out there which are made specifically to control DC motors. The problem that I am having is that most only support 4 amps or so. Does anyone know where I can find a controller that will support atleast 22 amps (ideally higher because I may need to upgrade)?
Title: Re: DC motor controller
Post by: Admin on December 11, 2006, 11:40:17 AM
Ok, what you want is a motor driver (search the forum for more info).

22amps is really high . . .

this can do 20A continious (30A peak)
http://www.dimensionengineering.com/SyRen20.htm

check this parts list for motor controllers and drivers
http://www.societyofrobots.com/robot_parts_list_electronics.shtml
Title: Re: DC motor controller
Post by: DanCF on December 11, 2006, 11:49:56 AM
Alright well the motor is only 18 amps, but I dont know what the rule of thumb is with amp padding. The one you listed would probably work. I don't see a serial port on that driver, does that connect to my MCU?
Title: Re: DC motor controller
Post by: DanCF on December 11, 2006, 11:57:01 AM
I found this controller which provides more amps, and is a little cheaper, it just doesnt have all the bells and whistles of the other one: http://www.lynxmotion.com/Product.aspx?productID=493&CategoryID=10.

It mentions that a .05HP motor is the maximum it can handle. Why would the HP matter as long as you are within the necessary amp and volt range?
Title: Re: DC motor controller
Post by: Admin on December 11, 2006, 12:00:45 PM
my rule for current is:
the allowable continuous current of the driver should be higher than motor stall current.

the 4th paragraph:  :P

"you can control a motor with: analog voltage, radio control, serial and packetized serial"

I recommend using a digital output pin of the microcontroller to do the radio control method.
Title: Re: DC motor controller
Post by: Admin on December 11, 2006, 12:06:41 PM
Quote
It mentions that a .05HP motor is the maximum it can handle. Why would the HP matter as long as you are within the necessary amp and volt range?

HP doesnt really matter . . . torque relates to current and voltage, but means nothing to circuit design. I think they wrote that just in case you dont know how to spec for current and voltage of a motor. Just use the specs at the bottom . . .