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Electronics => Electronics => Topic started by: mstacho on April 16, 2012, 07:26:58 AM

Title: H-Bridge ICs
Post by: mstacho on April 16, 2012, 07:26:58 AM

Howdy all,

I'm wondering if anyone has any ideas on an H-Bridge IC I can use.  My application is just simple DC motor control, but I'd like to do it using only one PWM input and one digital IO pin for direction control, rather than two PWM inputs that most ICs seem to need.

I know I can do what I'm looking for with AND gates and NOT gates, so it's not a massive deal, but I wonder if anyone has any other suggestions?  I can't use breakout boards because I want to make this with a minimal amount of external wiring (although some great breakouts exist that I've used in the past to do this very thing).

MIKE

Title: Re: H-Bridge ICs
Post by: billhowl on April 16, 2012, 07:44:45 AM

What is the voltage and current the DC motor need? how many motor for "only one PWM input and one digital IO pin for direction control"? is it two motors?

Title: Re: H-Bridge ICs
Post by: mstacho on April 16, 2012, 07:48:17 AM

7V, 0.2A.  Little motors, basically.  The L298 IC chip drives them pretty well now, but it's in a breakout board that implements the DIR/PWM stuff for me.

I don't mind having one H-Bridge chip for each motor.  I'm using one right now, in fact, but it needs two PWM inputs (apparently.  I'm up for being wrong on this :-P)

MIKE

Title: Re: H-Bridge ICs
Post by: billhowl on April 16, 2012, 08:07:18 AM

What is the stall current? why not use the L293?
(http://www.kmitl.ac.th/~kswichit/c52robot/circuit3.gif)

Title: Re: H-Bridge ICs
Post by: mstacho on April 16, 2012, 08:09:05 AM

Awesome, exactly what I was looking for.  Thanks!

MIKE

Title: Re: H-Bridge ICs
Post by: ben23f on April 19, 2012, 02:26:14 AM

Hi just wondering what is the difference between this and the SN754410 from Texas Instruments? Thats what im using and all the pins are identical, is there any difference?

Title: Re: H-Bridge ICs
Post by: infurl on April 19, 2012, 05:12:36 AM

According to the datasheets, the SN754410 can handle a continuous output current of 1.1 amps per channel (2 amps peak) and L293D can handle 600 mA per channel (1.2 amps peak).

Title: Re: H-Bridge ICs
Post by: Soeren on April 19, 2012, 10:33:39 PM

Quote from: ben23f on April 19, 2012, 02:26:14 AM

Hi just wondering what is the difference between this and the SN754410 from Texas Instruments? Thats what im using and all the pins are identical, is there any difference?

The L293 (less a trailing D) handles 1A (2A peak), has got a shorter rise time and only use half the letters/numbers ;)
IOW, you'll observe practically no difference in average use.