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Electronics => Electronics => Topic started by: wany on November 29, 2010, 12:20:53 AM

Title: Using an L293 as a H-Brigde
Post by: wany on November 29, 2010, 12:20:53 AM

So i am just wondering i seen circuit where people use LM293 as an H-Bridge to drive motor.
I am just wondering how to Hook up the L293 to do this. I have an idea but i am a bit uncertain and i just want to verify.
http://www.robotshop.ca/content/PDF/dfrobotshop-rover-schematic.pdf (http://www.robotshop.ca/content/PDF/dfrobotshop-rover-schematic.pdf)

This is a link to a Ardurio board hooked up with a L293.  Where do you apply the PWM to which PIN.
Yes as you can tell i am bit confused I see it has two inputs i am guessing on inverting input and one is not.

So where do i apply the PWM pin D8 and D7 right. and I just drive pin D5 and D6 high. But then how do i get it to do the reverse. Yes i am pretty sure i have the idea behind this wrong since doesn't make much sense.
So please explain.

Title: Re: Using an L293 as a H-Brigde
Post by: billhowl on November 29, 2010, 12:54:39 AM

(http://arduino.cc/en/uploads/Hacking/Atmega168PinMap2.png)
To apply the PWM from PIN D5 and D6 to ENA and ENB of L293, these two pins are for Enable H-Bridge.
The pin D7 and D8 are for direction change.

 

Title: Re: Using an L293 as a H-Brigde
Post by: Soeren on November 29, 2010, 01:20:08 PM

Hi,

Quote from: billhowl on November 29, 2010, 12:54:39 AM

To apply the PWM from PIN D5 and D6 to ENA and ENB of L293, these two pins are for Enable H-Bridge.

Enable inputs shouldn't be used for PWM, since they're slower shifting - the drive signals should be the PWM signals.