On Mon, 18 Jun 2007 14:37:50 -0700, Jim Lux wrote:
>Actually.. I think it would be better to make the "power handling"
>wires the short ones, and the "information handling wires" (the RS232
>connection) the long one. Rather than try and develop and build 8
>drivers (2 coils for each of 4 steppers), just buy an off the shelf
>long distance serial connection.
Jim, you may have hit the nail square on the head (as usual)! If the
StepIR will work that way from a user interface point of view (that is, if
the user controls aren't on the box that you want to move to the base of
the tower), that makes a lot of sense. RS232 will easily go several
hundred feet if low capacitance twisted pair (like CAT5) is used for each
circuit and the wiring avoids pin 1 problems and hum loops. Follow the
instructions in my RFI Tutorial, and be careful NOT "ground" the RS232
signal at more than one point. A good way to do this is to keep it off of
ground at the tower, and let it get its power from the shack.
If you want to go further, B&B Electronics (google to find them) has good
interfaces at moderate cost that convert the RS232 signal to a balanced
Jim Brown K9YC
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