Stepper driver supply from 220V*sqrt(2)

[sheena]

Hello!

Would like to ask if anybody have tried to make regulating current
driver supplied directy from rectified AC line. Sorry if such subject was
discussed here - couldn't find it - please delete if not appropriate.

Why to do that and why not to do that? As for me:

PROS:
- no need for extra power supply
- really fast step rates
CONS:
- big capacitor required (1000uF, 350V for me) - not that cheap
- hard to find integrated h-bridge for such high voltage
(anyway my steppers are unipolar, but would like
to make bipolar driver for future).

Would discrete h-bridge be complex for such high voltages?
(worrying about Vgs voltages on top mosfets).

Thanks for any comment!

Greetings!

[kineticstep]

You can buy that kind of driver for around $100 including the fan and heatsink in China. I don't sell them, but I did see them demonstrated and they work pretty well. Not sure what they used inside the box for h-bridge, but it had short circuit protection and a bunch of other features and wasn't very large. If you want to reverse engineer one I can put you into contact with someone.

[sheena]

Originally Posted by kineticstep You can buy that kind of driver for around $100 including the fan and heatsink in China. I don't sell them, but I did see them demonstrated and they work pretty well. Not sure what they used inside the box for h-bridge, but it had short circuit protection and a bunch of other features and wasn't very large. If you want to reverse engineer one I can put you into contact with someone.

Thanks for your kind offer, but I'm afraid that for $100 I cannot do better in DIY fashion. Do you remember anything about that driver? Model or anything else that would help me in finding the specs?
Was that one motor driver?

Greets!

[kineticstep]

PMed.