[SOLVED] Control 20A- 12V DC motor

[vishy71]

Hi

I wanna control speed of motor witch one is 12V - 20 AMP(actually 15AMP)
can u help me plz! can I use PWM to control this motor?
thanks

 

[Tahmid]

Yes, you can use PWM to control this motor. To control the speed only, you can use one MOSFET/BJT to control the motor. To control the direction as well, you need to implement a full-bridge circuit.

At this power level, I'd recommend that you use a MOSFET. What is the frequency of PWM that you are going to use?

You can use a POWER MOSFET, which has a low Rds(on). So, you minimize power loss and increase efficiency. However, this will require a driver circuit that will provide the MOSFET with around 10v from the logic level of the microcontroller and also supply more current.

Alternately, you can use a logic level MOSFET. However, they tend to have higher Rds(on). By using a logic level MOSFET, you can drive the MOSFET directly from the microcontroller. STP55NF06L is among the better logic level MOSFETs I've come across. It has an Rds(on) of about 18mohm. This is quite low for a logic level MOSFET and even comparable to POWER MOSFETs. The IRFZ44N has a higher Rds(on) than STP55NF06L. Using a logic level MOSFET simplifies the drive circuit.

Hope this helps.
Tahmid.

 

[kak111]

Schematics for example.......
check needed modifications for current

http://electro-circuit.com/wp-content/uploads/2011/06/Speed-Controller-Motor-DC-24V-20A.gif

http://ww1.microchip.com/downloads/en/AppNotes/00531e.pdf

http://ww1.microchip.com/downloads/en/appnotes/00807a.pdf

**broken link removed**

KAK

 

[bigdogguru]

Here are some appnotes and example projects:

PICMicro Tips ‘n Tricks DC Motor Control

PIC Based Speed Controller

H-Bridge Microchip PIC Microcontroller PWM Motor Controller

These should give you some ideas concerning implementation of DC Motor Control.

 

[wizpic]

Here's another one
Silicon Chip Online - 12V-24V High-Current DC Motor Speed Controller, Pt.1

You don't have to use the whole thing but gives you the idea

 

[vishy71]

Hi

thanks anybody.thanks
I must try all of youre ways.so this treat must be cosed! if i find an error or problem I will be come back.thanks