12V DC bidirectional motor and microcontroller

[Tyler62]

Im looking for some insight on controlling a dc motor and also a couple of 12V actuators with a microcontroller. I need some help with how exactly i can reverse the polarities automatically to reverse the direction of the motors. Is there and circuitry that can switch the directions of motors? Before anyone tells me to use stepping motors, the actuators are not equipt will them so i need to control a simple dc motor. Thanks in advance.

 

[cbarn24050]

Hi, you need a H bridge, look up L6209 datasheet to get you started.

 

[ScottyUK]

Or a DPDT relay, and a transistor to interface to the micro.

It really depends on how often you want to reverse direction. cbarn's solution is better if you are frequently reversing; the relay will work out cheaper and simpler.



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[automatic2]

Depending on you power requirements, Dedicated PICs are available that will direct drive. Onboard profiling, limit switch inputs, etc.

 

[Madcow]

Try this

http://www.microchip.com/1010/suppdoc/appnote/all/an893/index.htm

You can reverse by changing 2 bits in software.

 

[BoonS]

If you are trying to controle 3 or more motors, controling the 4 H bridge lines and minimize transistor drive crossover may require too many lines and much more software and be timing critical.

For 12V applications where motor current may be over 2A I found a very good Hbridge motor driver from ST the TD340,

http://www.st.com/stonline/books/ascii/docs/7048.htm

it allows you to reverse using 1 pin
and PWM for power control.
Syncronous high side rectification for minimal heat.


Boon Spangler, Principal EE
Brother International Corp.,
Research and Development
7777 North Brother Boulevard
Bartlett TN 38133
Tel:: 901 379 1000 ( central)
Tel: 901 379 1697 (direct)
Fax: 901 379 1710
EMAIL: boon.spangler@brother.com

 

[nbucska]

Some DC motors have permanent magnet (PM), some have field winding.

If there is field winding internally connected to the
brushes (serial or parallel) so it has only 2 accessible
leads, the direction can't be reversed.

In the case of PM or 4 accessible leads you can change
the polarity of one coil ( if there is wound field)



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