Closed loop stepper motor kit power supply

[the great waldo]

I'm contemplating getting 3 of these kits
https://www.omc-stepperonline.com/1-...or-driver.html
I've got parts for an unregulated power supply 36 volt 500va toroidial transformer which should give me just over 50 volts (36x1.4) am I pushing my luck as the listed voltage on this kit is 36-48volts ? Or should I use a lower power transformer ? or can I reduce the voltage output somehow ?
Thanks in advance
Andrew

[Voicecoil]

Yes, you could be pushing your luck, depending on the robustness of the driver module . 36V x root 2 =50.9V peak, subtract 1.6V for rectifier losses and you'll get a peak on-load voltage of 49.3V. But due to the regulation factor of the transformer, when you're not pulling much power it will rise by probably 5% = 51.8V. And that's at nominal mains, remember it can vary by up to 10% (though I've never seen it up by more than 6% here), so taking that figure you could land up with 55V off-load, high mains. I anticipated the same problem on my setup (albeit with a 35V transformer which makes things a tad better) so have designed a regulator circuit which limits the voltage to slightly over 49V. I haven't fully tested it yet, but will let you know how it works once I've given it a thorough work out.

[the great waldo]

Hi Voicecoil
If you get your voltage dropper tested I would be grateful to see the circuit.
Cheers.
Andrew

[Voicecoil]

Sure thing. BTW, it also does a nice soft start to charge up the reservoir caps gently without pulling 60+ amps on switch on.

[Doddy]

What's the primary coil rating of the toroidal? If 220V then you might be well over the design limit of 48V with a 240V supply.

Personally, if the rectified voltage was 49-50V I probably wouldn't lose sleep over using them myself, but would never design around this for a third party.

[JAZZCNC]

I've used and killed these drives.! . . They don't tolerate any overvoltage. 51V will 100% Kill them and with Back EMf and/or Mains fluctuations you will hit 51V with 36V primary. I Wouldn't go much above 30Vdc with Prime and to be honest you won't notice any difference the few volts gives you.

[the great waldo]

What's the primary coil rating of the toroidal? If 220V then you might be well over the design limit of 48V with a 240V supply.

Personally, if the rectified voltage was 49-50V I probably wouldn't lose sleep over using them myself, but would never design around this for a third party.

Hi Doddy
We have 220 volts here in Austria,
cheers
Andrew

[dazp1976]

I'm contemplating getting 3 of these kits
https://www.omc-stepperonline.com/1-...or-driver.html
I've got parts for an unregulated power supply 36 volt 500va toroidial transformer which should give me just over 50 volts (36x1.4) am I pushing my luck as the listed voltage on this kit is 36-48volts ? Or should I use a lower power transformer ? or can I reduce the voltage output somehow ?
Thanks in advance
Andrew

I'd be a bit iffy.
Lower the power.
https://electro-dan.co.uk/electronics/wiringtrans.aspx
Personally I'd get a set with a 80VAC capable driver and just series wire a 35 to 40v toroidal.
I've seen motors that have the same or higher torque claiming only 2.2mh inductance.