Search results

  1. A

    Simple Unipolar Stepper Driver

    Yes, you are right it is a huge waste of power, which is probably why most modern drivers use a current chopper.  Could you list a couple, so that I could look into them a bit more? I have, but used a very different method.  I had some low power transistors that I attempted to match and stack. ...
  2. A

    Simple Unipolar Stepper Driver

    Thank you audioguru... I appreciate the time you are taking to help me along. Yes, this makes sense to me.  But.. to make sure we are on the same page... a stepper coil supplied directly with 6V and 1.5A reacts slower than a stepper plus resistor (or current sink) supplied with  more Voltage...
  3. A

    Simple Unipolar Stepper Driver

    Ok thank you, I will get rid of the zener and add in a regular diode.  IIRC... that will give me about 0.65V a peice... so say I use 1.. I need a 0.4 or 0.5 ohm R4.  If I use two diodes (3 total now)  I have R4 at 0.9 Ohms... and so on. So any advice on sizing R3 and power rating the...
  4. A

    Simple Unipolar Stepper Driver

    Alright... lets try this: Found out my stepper voltage rating... can be safely ignored... the 1.5A is what cant be exceeded.  My power source is a 140W ATX. I have added a constant current source to each coil.  If I make D3 a 2V Zener... that means R4 should be ~1.3Ohms ... which will limit...
  5. A

    Simple Unipolar Stepper Driver

    audioguru, thank you for the reply
  6. A

    Simple Unipolar Stepper Driver

    Anyone? Any ideas?  Do I need to supply more information?
  7. A

    Simple Unipolar Stepper Driver

    This is a quick attempt at a diode/transistor based current source.  Again... dunno if this is right... but I think my load is in the right place this time.  I think I would have to use a PNP for it to be correct on the other schematic.
  8. A

    Simple Unipolar Stepper Driver

    Hello everyone... it looks like you all have a great forum here! Brief introduction... I have some basic experience with electronics.  My problem is I have been out of it for a number of years, and most of the basic concepts that had to come easy to me, have been forgotten about.  A few days...
Top