Krumlink

For my *secret* robot I want to use a small very compact easy to build freeformable H-Bridge that can handle up to 1 amp at 9V. The robot it will be in will be *secret* hence I must be very *secretitive* about this *secret* project, codenamed *secret* robot. I will post the results of this *secret* robot and its *secret* specifications once I complete the *secret* robot. I would rather use the 2N2907A and the 2N2222A because I have over 100 of each that I got from my favorite supplier, which is *secret*. I would prefer the H-Bridge to have a *secret* device inside of it that would prevent me from smoking it, or what I *secretly* call the anti-smoke device, which name was reccently de-*secret*-itized.

I willl use my *secret* robot for the good of mankind

__________________
MechTronics

World of Warcraft is a disease

blueroomelectronics

Try a SN754410 1.2A drivers, with diode clamps.

__________________
Bill
Smart Kits build Smart People
http://www.blueroomelectronics.com

Krumlink

I dont know....

What company makes it? Does maxim make motor Drivers? I really like TI and Maxim

__________________
MechTronics

World of Warcraft is a disease

kchriste

TI makes the SN754410
http://focus.ti.com/docs/prod/folder.../sn754410.html
and the L293
http://focus.ti.com/docs/prod/folders/print/l293.html
There are others, but they are a *secret*!

__________________
--- The days of the digital watch are numbered. ---

bryan1

If your secret robot is so secret keep it secret and leave us all alone

__________________
" The only way to avoid human error is to avoid the use of humans"

Krumlink

lol ok it is for my walking robot

__________________
MechTronics

World of Warcraft is a disease

Hank Fletcher

Didn't we sort this out already? I'd thought we'd come to the conclusion that you could get 2A per chip, and that diodes were not required (because they're included on the chip - but maybe that's what you meant)?

Krumlink, you need to loosen up and share your ideas for your walker robot. It's easy to be tempted into coveting ideas, for fear that someone might "steal" them (or accuse you of stealing them), but that fear has a false basis.

Strangely enough, you're much more likely to come up with an original idea the more you share it with others. Also, by posting your work and process on this forum, you can establish precedent for your ideas by way of witnesses should the originality of your project be called into question.

Think of sharing your ideas as a type of pre-emptive protyping. Everyone has their own perspective, so when you share ideas with other people there's an opportunity there for people to point out how things can fit together in a way you otherwise might not have thought about. That's a bonus, not a threat, to your inventions. I'm blown away by how many times the way around a seemingly insurmountable task for me has been elucidated by someone with a simple solution, just because they were able to see what I was trying to do from a different point of view. That's the benefit of collaboration, and that in turn is the virtue of getting along with other people: the sum of collective minds tends to be greater than the parts.

blueroomelectronics

Might as well build something like the Parallax walking bot. It uses two servos and although it's designed for the BASIC Stamp any small micro should have no problem with a pair of servos. The key word is "micro" would be tricky to do it with discreet logic.

__________________
Bill
Smart Kits build Smart People
http://www.blueroomelectronics.com

Hero999

If I remember correctly, the 2N2222A will don't pass 800mA and the motor will draw a lot more than that when started.

You could parrallel a load of them using 0R5 emmitter ballancing resistors but you're better off using MOSFETs.

__________________
I also post at the following sites:
http://www.stop-microsoft.org http://www.heated-debates.com
Screen name: Aloone_Jonez

theinfamousbob

Good chip, but the diodes aren't needed(page 2 in datasheet).

I've used them before, and they can be stacked if the load is too high. Looks like they're 1.1A continuous.

Attached Files

3177384.pdf (107.0 KB, 21 views)

__________________
-Ian

blueroomelectronics

The schematic of the outputs show a pair of diodes.
http://www.kronosrobotics.com/an101/AAN101.shtml

edit: I read your message wrong, thought you said the diodes were needed...

__________________
Bill
Smart Kits build Smart People
http://www.blueroomelectronics.com

Wingmax

[quote=blueroomelectronics]Might as well build something like the Parallax walking bot. It uses two servos and although it's designed for the BASIC Stamp any small micro should have no problem with a pair of servos. The key word is "micro" would be tricky to do it with discreet logic.
[quote]

Thanks for the suggestion. It's a very good book, can be downloaded too.

__________________
May the force be with you.


My project: Simple White Line Follower

http://au.youtube.com/watch?v=8Z_MmrdH4oc

http://i271.photobucket.com/albums/j...nefollower.jpg

Krumlink

THe ratings are 60ma no load, and 600ma stall at 6V. I am building this "style" of walker:



I have seen books saying to use the SN74AC245N Paralleled up to create H Bridge Drivers, but my motors wont work with these, so I was thinking of making this kind of H Bridge:



Only thing is that you remove the Schmitt Inverters on it. I will use the one above, beacuse it is easily free formable and easy to make.

__________________
MechTronics

World of Warcraft is a disease

3v0

Why do you want to build a H-Bridge from transistors when you can buy the SN754410A suggested by Bill?

I can only speak from my experiance. I have built the Miss Motor H-Bridge using 2N2222's and 2N2907 transistors. It is not a great preformer. The SN754410A transfers more power at a given voltage.

If you are going to use transistors at least use the ones I mentioned above. David Cook compares transators here. The ZTX ones are nice but spendy. Do not think they have samples.

Krumlink

I was going to use the 2N2222 and 2N2907s, because I got a ton of em.

__________________
MechTronics

World of Warcraft is a disease