--- DC motor DriveR ---

[benji]

I was thinkin to build/design a circuit to optimally control dc motors
i mean

1/ speed
2/ position
3/torque
4/ brake  << most important

anyways the most used way to control speed is PWMing the dc motor so the average voltage would change
but,, is this efficient enough ? wouldnt be more efficeient if we decrease the supply voltage?

i was thinking if a group of us share the design , we can build it together,, wut do u think?

[airman00]

you are trying to make continuous rotation or not?

[benji]

both ,,

[ArcMan]

anyways the most used way to control speed is PWMing the dc motor so the average voltage would change
but,, is this efficient enough ? wouldnt be more efficeient if we decrease the supply voltage?

i was thinking if a group of us share the design , we can build it together,, wut do u think?

A PWM motor drive is very efficient.  A PWM motor drive effectively decreases / increases the supply voltage to the motor by vary the PWM duty cycle.  There are many, many designs out there already and even chips that implement those designs.

[benji]

well i was talking about the 4 things i want to control,, im thinking an individual speed/torue/position driver

[ArcMan]

Oh.  OK.  That does sound like a good project.

There is a commercial version:
http://www.pololu.com/catalog/product/425

but I haven't seen many hobbyist-designed solutions.

[Webbot]

I was thinkin to build/design a circuit to optimally control dc motors
i mean

1/ speed
2/ position
3/torque
4/ brake  << most important

anyways the most used way to control speed is PWMing the dc motor so the average voltage would change
but,, is this efficient enough ? wouldnt be more efficeient if we decrease the supply voltage?

i was thinking if a group of us share the design , we can build it together,, wut do u think?

Have you seen my Motor Driver tutorial at http://www.societyofrobots.com/member_tutorials/node/159

This helps set speed etc and the Tri-State Switch also provides braking.

[benji]

hey webbot ,,good work ,,ihave seen some ICs ,they could be helpfull
they can be included in such a circuit i guess,,
but im talking about somthing bigger,,, maybe close to industrial inverters for ac motors

[benji]

well first , considering such a project one should model the dc motor,, have the equivalent circuit
i ve been lookin for it and most sites on the internet tell that its (R ,L ,emf) the emf is propotional to the rotational velocity

any other components to include?

[benji]

now i know where to start , first to model then to build the controller, im gonna use matlab for modeling/controller PID design

i found this link very benefical and it has some other links mentioned below in the page

www.engin.umich.edu/group/ctm/examples/motor/motor.html