[Stevie]

how can you use a unipolar as a bipolar
Just a quick question; do i simply miss the black center tap
also how do you make a PC power supply turn on with out a PC; it just sits there

[Urgundiz]

1) to use a unipolar as a bipolar, just ignore the common wire. It doesn't matter if is 5 wires or 6 wires, just use the end coils wires and wire it to the driverboard like as bipolar.
2) if is AT PSU, it works fine as is, if is a ATX PSU you need to put a load in it, you can use a 5ohm25watt resistor betwenn the 5V (red and black, yellow and black is 12V) of one of the plugs.

hope it helps
/U

[Stevie]

Hi; thanks; yes it is an ATX

I figure I'll just hook into my regular PC for this quick test; I never put the sides back on anyway

[Al_The_Man]

I believe the ATX supply has a PS-ON pin which is pin 14 on the 20 pin connector, it has to be grounded to pin13 to run and will switch on without load.
Al

[Stevie]

thanks Al; I'll give it a shot (I have spares)