Re: Opinions on this Chopper drive schematic? Hold on!

Hi,
Yep, Mach1 and TurboCNC both work fine with this chip. It is what
I use on my three axis and single axis boards. You can see my boards
at:

http://www.xylotex.com

The chips are covered with heatsinks in the photos, so you can't
actualy see the PLCC chip though.

I'm not sure of the voltage limitations of the 297 style chip, but be
aware that the 3977 has a 35V limit which includes back EMF. The
maximum suggested running voltage is 30V. You can get good
performance at 24VDC however. I suggest using a fan when running at
24VDC and at the higher current range of the chip (blowing across
the heatsinks attached).

<SALES PITCH ON>
With my three axis board for $125.00 you get an IDC26-DB25 cable that
allows you to plug into a PC's parallel port (or parallel port
extension cable), and a "power steal" cable which allows you to get
5V for the logic side of the board from a spare floppy/hard disk
drive power connector inside your PC. Setting of the motor current
is done through three different pots onboard. You adjust them and
measure voltages at Vref points with your multimeter to set the
current for the motor. The motor connections have screw terminals as
does the connection for motor power (VBB and GND). If you require a
4th axis, I sell a single axis board for $40.00 that can get its' 5V
power/GND and STEP & DIR signals straight from the three axis board
via the "4th axis add-on cable" that comes with the single axis
board. All of this simplifies putting together a lower voltage/lower
current stepper motor system.
<SALES PITCH OFF>

Thanks,

Jeff

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "ghidera2000"
<ghidera2000@y...> wrote:

> Just discovered the A3977 driver chip on the allegro site. Been
> reading the specs and this looks a lot nicer than the 297/298
> pairing - cheaper too since its a single chip :D
>
> One question though, based on what I've been reading, its looks

like

> I'll probably want to get Mach1 to control this puppy. Can Mach1
> control the A3977 properly?