is this the place for a newbie question?

[Colin Stutt]

I have changed a 3 phase motor to operate as a stepper. I now want to
control it from the printer port of my computer, the programming of the port
is not the problem for me, I am looking for help with the electronics, What
would you suggest as a circuit to control 5v input from the port to 56vdc
output? I have tried relays but they are too slow to get the stepper to the
speed I need. Would I be correct to say I need to use (is the word) descrete
components?
Cheers to you all in anticipation of your help

 

[ptw]

What
would you suggest as a circuit to control 5v input from the port to 56vdc
output? I have tried relays but they are too slow to get the stepper to the
speed I need. Would I be correct to say I need to use (is the word) descrete
components?

You need a transistor. A discrete component is just a "not inside an IC
chip" thing.

An example setup with a NPN transistor:
+5V to base (resistor may be required)
+56VDC to motor to collector
Common GND to emitter

Someone else might suggest a part number.

 

[James Thompson]

I have changed a 3 phase motor to operate as a stepper. I now want to
control it from the printer port of my computer, the programming of the
port
is not the problem for me, I am looking for help with the electronics,
What
would you suggest as a circuit to control 5v input from the port to 56vdc
output? I have tried relays but they are too slow to get the stepper to
the
speed I need. Would I be correct to say I need to use (is the word)
descrete
components?
Cheers to you all in anticipation of your help

How much current draw will your motor need? You may be able to get by with
a uln2023a high voltage/ high current driver type chip if the current is low
enough. It can switch loads at 95 volt from ttl inputs. I have a drawer
full of em if you can't find any..