How to control the motor

[Tommy_Sia]

I'm curently having some problems with the motor application.
First of all, the motor i'm currently using is a DC motor.
Most probably a 12-24V DC-Motor.
The DC Motor should rotate in both back and forward directionn automatically..
Is there any other method to control the change of direction of the motor without involving a microcontroller..?
Can any mechanical method involve..?

 

[ante1]

Hi Tommy,
Welcome to this forum.

Are you referring to any special motor application?
Can you describe what you like to accomplish with the motor circuit? Usually there is no reason to involve any microcontroller to control a motor.

 

[MP1]

Tommy,
It sounds like you are trying to describe what is called an H - Bridge for the motor control. It is built with 4 transistors.

MP

 

[Yevgenip]

I have a circuit for that - it works with only two transistors, but with two batteries.
I can't upload the picture right now, but I'll post in a while.

 

[CRE]

Do keep in mind that while most DC motors will operate in either direction depending on the polarity of the voltage, that if it is not brushless or designed for such operation the brushes inside may be damaged... it's all a matter of how it's constructed of course.

 

[ante1]

CRE,

It

 

[Yevgenip]

I have troubles uploading so I'll explain:

You connect the emmiters of an NPN and a PNP transisotr to one connector of the motor and connect the other connector to the grounded connection of the positive end of one battery and the negative end of another.
Connect the other ends of the battery to the transistors collector accordingly through a selector switch.
Connect the transistors bases together and then to the collectors. Use resistors when needed.
You can also control the motors speed by connecting a potentiometer to the base input.

 

[Tommy_Sia]

ya.....i'm not using microcontroller to control it..
instead i m using a H-Bridge instead...
well....i'm applying it in my project..which is the "Automatic Swing System"
Have u seen those playground swings....?
my project is based on that concept....the only thing is that it swings back forward automatically....

I'm attatching a circuit which i tot could help me solve my problem..
Can you give me any comment regarding this circuit....

But i was confuse about the operation.
For example, if the motor is rotating in clockwise direction, can i immediately change the polarity to rotate it in the opposite direction?
By doing so, can the motor be damage due to the immediate change of current?

Well i having problem uploading it........
so

The_H_Bridge_for_DC_Motor_Control.zip

 

[ante1]

Hi Tommy,

I think the motor will suffer if you just switch from forward to reverse without any time to

 

[MP1]

Why not a motor on each side and alternate the on-state? The sensors that ante has suggested could determine which is on.

MP