Motors

[goblin_techies]

hi,
just want to know what the differences of these:
stepper motor
DC motor
servo

thanks!

 

[qsiguy]

Well here are some links explaining each.

Stepper motor
https://en.wikipedia.org/wiki/Stepper_motor

DC Motor
https://en.wikipedia.org/wiki/DC_Motor

Servo
https://en.wikipedia.org/wiki/Servo

 

[Sceadwian]

Simple Answer.

DC motor = a motor powered by a DC current. Current controls motor direction (in it's simplest form) Basically on or off full.

A Stepper motor is a multi poled DC motor, driven by pulsed DC or AC waveforms from generall four coils. Very high degree of control in rotation speed. Used extensivly in printers, and they're accurate to about 300-600 DPI

A Servo is a motor with feedback control. Generically it is fed a position and through feedback from it's output stage is driven as close as possible to the true desired position.

Each of these generic definitions can be further complicated with study, but they all bascially have the same features. Control of a motor and it's direction and applied force for a specific reason.

 

[goblin_techies]

Thanks....
but how can i controll them using computer? especially the stepper motor

 

[penoy_balut]

first you have to write software, any language will do, but VB is easiest in creating GUI, then send data to the port depends on the motor used, either unipolar or bipolar, steps in angle, volts, winding resistance, torque required etc

 

[Sceadwian]

The drive circuitry for a bipolar is more complex as they require h-bridge circuits to drive. A unipolar stepper motor can be driven by simple transistor or mosfets, one per line. You can drive the fets or transistors from say a parallel port. Unipolars have to have each coil sequentially energized, sequentially energizing pairs of coils will give you a half step (doubling the resolution) and using more complex waveforms you can micro step but only high end printers and people that need VERY smooth transistion between steps micro step to that degree. Just look up unipolar stepper and parrallel port on google, should keep your reading for hours. Including several circuits for driving one from a parallel port.

 

[goblin_techies]

what h-bridge??
do you have a schematic diagram of a h-bridge????

 

[dknguyen]

https://www.modularcircuits.com/h-bridge_secrets1.htm