Re: stepster and driver

Doug,

It would be helpful if you could list the website you refer to...

In the absence of that, here's a guess as to what you might have
seen, and how it might have been misunderstood.

Stepster by itself only drives the pins of a parallel port, setting
voltages on certain pins high and low. These voltages are then used
by a driver of some type to make motors turn. I believe you already
understand this.

Here is the possible misunderstanding; Yes, there ARE driver cards
which; A)sit inside the computer, B)use the signals from the parallel
port to determine how the motor(s) is/(are) moved and C) Use the
computer power supply. Other boards do A and B, but use a separate
power supply. Microkinetics offers such a board, optidriver, I think.

Then there are very simple small drivers which can fit in a gender
changer size package. One former mfr. of this type was Digital
Systems, and it worked their MINC software. The board still was fed
by a parallel port, and inside had only a few parts, which were
darlington drivers, and a connector for a wall wart type power
supply. Similar types are used by the telescope positioning crowd...

As Jan R (troll) has already said, you would not drive a stepper
directly from the parallel port pins. BUT, a driver which CAN drive a
stepper can be quite simple (4 transistors, 4 resistors); though it
will have a poor level of performance, relative to other "typical"
choices.

More extensive electronics can also be put in the computer case, on a
p-port card, which stepster could drive. Thus, a driver CAN use the
computer supply, and CAN be part of a parallel port "card" (though it
will have to be one designed especially TO include stepper driving).

Hope this helps,

Ballendo



--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Douglas Pollard"
<dougpol1@o...> wrote:

> There seems to be an implication on at least one web sight

that stepper motors can be run off of a program like Stepster through
a parallel port and parallel port card. Does this mean that a driver
board is not used? If so does the computer supply the power or is a
separate power supply needed. Does anyone know of a site that
explains all this. Will appreciate any help you folks can give.

> Doug
>
>
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