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Topic: H Bridge Chip Suggestions (Read 1 time) previous topic - next topic

dezguy

I've been working on a robot project, and I'd like to build a custom PCB which combines a avr microcontroller, power supply, h-bridge and sensor circuits. My attempt is partially to learn about making my own PCB, but also I'd like to make a nice clean robot without a bunch of wires hanging off it.

So far nothing has been too overwhelming, but I came across quite a few h-bridge chips in my research and I wondered if there was some guidance from the group on some of the options.

My needs are pretty basic. Two 0.15 amp 3v motors, I'd like to operate fwd/reverse with PWM speed control.

A few chips I've looked at:

L293D
754410
L298
LMD18200

Does anybody have experience with these chips and how did it work for you?

I have a couple of 298s in my stock, but I don't have fast recovery diodes. But, overall it seems a bit overkill for my needs.

If you need further details just let me know.

Many thanks,
Mike

CrossRoads

I was just reading the L293D datasheet for someone else, looks like it'd do the trick for those motors.
Built in diodes too.
Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

zoomkat

Be aware that these types of chips may have a voltage drop across them that might be significant in the 3v range. 4.5v might be needed to get full performance from the 3v motors.
Consider the daffodil. And while you're doing that, I'll be over here, looking through your stuff.   8)

dezguy


Be aware that these types of chips may have a voltage drop across them that might be significant in the 3v range. 4.5v might be needed to get full performance from the 3v motors.


I was planning on a 9V power supply (AA batteries) for the entire board, so I'm thinking I should be ok?

dezguy

#4
Feb 26, 2011, 04:48 am Last Edit: Feb 26, 2011, 05:53 am by dezguy Reason: 1
I'm wondering, did I get the hook ups on the 293D correct (see circuit attachment)?

Do they make a dual inverter? Or do I need to use a hex, and waste the empty pins?

CrossRoads

Sure, you can get a dual inverter - its called 2 transistors :)

But if you're not doing much else, why not just use 2 more pins?
Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

dezguy

Yeah that looks much simpler. :)

Do you mean, use two pins on the mu?

CrossRoads

Yes, 6 pins total from the arduino. 1A ,2A, 1-2Enable, 3A, 4A, 3-4Enable.

Transistor and 2 resistors about as simple as it gets for an inverter. I used that to invert a TTL level serial stream so the 328 UART would read it correctly.

You could try this sn74lvc2gu04 from TI if you don't mind surface mount
http://focus.ti.com/lit/ds/symlink/sn74lvc2gu04.pdf
Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

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