PIC Step & H-Bridge

[LazyBee]

Hello,

is it possible to drive the PicStep with a normal discrete H-Bridge that generates motor current like the L298?

Thanks

LazyBee

[LazyBee]

Hello,

no ideas?

LazyBee

[kodalo]

Originally Posted by LazyBee Hello, is it possible to drive the PicStep with a normal discrete H-Bridge that generates motor current like the L298? Thanks LazyBee

I am not expert, but I think software is written for LMDs not for L298. At least, L298 doesn' support microstep.

[LazyBee]

Hello,

yes, you are right.

Now I'm looking for an other possibilty to drive a H-Bridge with a pic for my cnc.

Thanks

LazyBee

[dtman2]

What is your reason for wanting to move away from the LMD18245? It is a bit expensive at 2x$12 per axis, but it has all sorts of advantages over a discrete implementation. Do you need more current than 3A, or much less?

[LazyBee]

Hello,

yes, I would like to build a stepper driver with 5 or 6 amps or more (bipolar motors, minimum 1/8 step). I want to have more power to play around different cnc machines.

I the moment I use a driver with IMT901 from Nanotec wit only 2 amps.

A set of LMD is a little bit expensive.


LazyBee

[10bulls]

Originally Posted by LazyBee ...I would like to build a stepper driver with 5 or 6 amps or more (bipolar motors, minimum 1/8 step).

http://pminmo.com/ has a great selection of drivers. There maybe something there that could be adapted. I hate to say it though, there are some great prebuilt stepper drivers around now for not much more than you could build it yourself (much cheaper if you factor in time).

Saying that, I have 2 x 15.2A steppers that I want to start using next year so I too will be looking into high power designs. My PICSteps drive these motors fine at 3A 40VDC though!

One idea I had was to use the drive circuit from the UHU servo motor driver or the Open Source Motor Controller (http://www.robotpower.com/products/osmc_info.html) and connect 2 of these to a pic (or maybe even a DSP if I start taking my brain tablets).
I think this would be more for fun than economics though.

[LazyBee]

Hello,

yea a had a look at http://pminmo.com/ . But I don't foud what I'm looking for. My first idea was to use mircochip AN822 without the L298 and to use instead L298 a discrrete h-bridge. But the AN822 works on a serial port and my software is for a par port (step/direction).

LazyBee

[10bulls]

Originally Posted by LazyBee ...But the AN822 works on a serial port and my software is for a par port (step/direction).

AN822 uses a step and direction pin AND a serial input. I am pretty sure they will work without the RS232. You'll only get 2A though and they can get pretty hot. I think you can parallel them to get more current though this may get a bit tricky with the current sensing.

[LazyBee]

Ok. I want to have a deeper look to this AN. I think it is interesting to start with one L298 and look how it works.

With kind regards.
LazyBee

[dtman2]

How about this h-bridge, 50V, 20A

http://www.irf.com/product-info/data...rel/m3h310.pdf

I got my picstep working yesterday, drove the keling 282 oz-in steppers without warming up much using a 40V supply, no mechanical load though. Used some old pentium 2 cpu heatsinks I had, didnt need to hook up the fans on them. This was the first time I built anything with a PIC in it, they are impressive little devices.

[dalescnc]

hi all Anyone have a link to circuit using L297 with 2 L6203 outputs with filter back to the ref voltage or gated back to the ref ? thanks