DC motor controll using a PIC Microcontroller

[kad_911]

PIC controlled motor

Im using a PIC16F877A to control a 12V DC Motor.
How can i controll the speed of the motor?

I know how to use pwm but how can i apply that here because the output of the PIC is 5V but i want the motor to run at 12V max...

 

[anandpv2009]

Use l293d motor diver IC.
Good luck

 

[IanP]

Use a power MOSFET or BJT .. see attached picture ..

Also see:
http://picprojects.org.uk/projects/ppc/index.htm

IanP

 

[hameeds01]

u can control the speed of DC Motor via PWM

 

[Tahmid]

Hi,
You can use a MOSFET like IanP showed, or you can use a BJT, but for MOSFET, a logic-level MOSFET, eg, IRL3303, should be used if you drive the MOSFET directly from the microcontroller. If you use a power MOSFET, eg IRF3205 you should use a MOSFET gate driver, like TC428, IR2110, etc.

Hope this helps.
Tahmid.

 

[kad_911]

can u be more specific? like how the PIC comes in and how to control speed?

 

[Tahmid]

Hi,
You have some frequency, eg, 1kHz and you have a variable duty cycle (on time). You have time period of 1ms. So 50% duty cycle (50% on time) = 500us = 50% motor speed.
You can have a variable resistor or switches that set your speed accordingly, by changing the duty cycle.

The output PWM from the PIC goes to a driver and then MOSFET which controls the motor.

Hope this helps.
Tahmid.

Added after 5 minutes:

Take a look at this:


Hope this helps.
Tahmid.

 

[kad_911]

thanx.. but what i dont understand is,

The output PWM from the PIC goes to a driver and then MOSFET which controls the motor.

what is a motor driver?

 

[IanP]

MOSFET is the motor driver ..
MOSFET’s gate is directly driven by your PIC, and that’s how you implement pulse-width-modulation ..
Just look at the drawing:
mosfet and motor2.gif

IanP
:idea:

 

[anandpv2009]

For bi-directional operation use L293D dual channel H bridge (Low power, 600mA max/channel)
http://letsmakerobots.com/node/2074
http://www.extremeelectronics.co.in/avrtutorials/pdf/avr_tutorial7---motor-control.pdf
(Don't follow programs of above links)


And you can use PWM to control speed of motor.

You have to use power devices if u want to drive heavy machines, otherwise you can use Dual channel H bridge l293d.

Specify your purpose/Motor power and C compiler/(using assembly).

Good Luck.

 

[hameeds01]

PIC (PWM) ----> MOSFET Gate Driver --------> MOSFET Motor Driver -------> DC MOTOR