Re: ebay board kits v 542 boards
Quote:
Originally Posted by
crossleymarko
are all the wire colours on the tororial universal...?
Try this one:
http://www.arceurotrade.co.uk/projects/PSU/index.html
(I notice that diagram has fuses on the secondary side, however I did not include them since each stepper driver already has an internal fuse to protect against over-current. Also any 'nuisance' blowing of that fuse could damage the stepper drivers.)
The colours are not universal, however there is always a clear diagram on the transformer which labels which colour is which.
Re: ebay board kits v 542 boards
Quote:
Originally Posted by
Jonathan
Also any 'nuisance' blowing of that fuse could damage the stepper drivers.
No the fuse is on the supply input. Stepper drives are damaged when the motor supply leads are interfered with.
Re: ebay board kits v 542 boards
Quote:
Originally Posted by
John S
No the fuse is on the supply input. Stepper drives are damaged when the motor supply leads are interfered with.
It's on both sides in the diagram on Arc Euro. Stepper drivers can be damaged if the power wires are suddenly unplugged for similar reasons to doing the same to the motor wires. It's less likely but still possible since interrupting the current causes a high dI/dt which will cause a voltage spike.
Re: ebay board kits v 542 boards
Re: ebay board kits v 542 boards
Quote:
Originally Posted by
crossleymarko
You would still ideally want two of those. No reason to spend £10 on a high quality capacitor when three £0.82 capacitors in parallel will do the job better.
Re: ebay board kits v 542 boards
Quote:
Originally Posted by
Jonathan
It's on both sides in the diagram on Arc Euro. Stepper drivers can be damaged if the power wires are suddenly unplugged for similar reasons to doing the same to the motor wires. It's less likely but still possible since interrupting the current causes a high dI/dt which will cause a voltage spike.
So what happens when the onboard fuse goes or does that behave differently ?
Re: ebay board kits v 542 boards
overkill is my theory for future upgrades.. same with the transformer. what would you recomend for overkill..
also i read it as your stepper is rated at x volts. how is the homebrew psu regulated.. to said volts..
Re: ebay board kits v 542 boards
Never rely on colour codes being universal, not even from the same maker, just something I found out.......
Colours for the trafo linked to by Jonathan are in the PDF:
http://www.rapidonline.com/pdf/88-3781.pdf
Grey and Violet are joined, Blue is Neutral, Brown is live on primary.
Orange and Black joined are 0V
Yellow and Red joined are +V on secondary
Steppers are current driven rather than voltage, the drives take care of the current regulation just need a stiff enough power supply and will drive enough volts through to maintain current.
Cheers
Adam
Re: ebay board kits v 542 boards
so orange and black is -v on the secondry... think i get it. how you worked that out i have no idea.. as grey is 115v and violet is 0 volts.
also on the description ie. 500va 0-35 0-35.
does this mean its 70v output.
Re: ebay board kits v 542 boards
Quote:
Originally Posted by
crossleymarko
how you worked that out i have no idea.. as grey is 115v and violet is 0 volts.
The position of the black dot on the diagram shows the relative polarity of the windings, so if a primary wire with a dot is connected to one without, and the other two are connected to the mains that's correct for 230V. If the dotted wires are connected together, then to the mains and similarly for the wires without the dot then the primary windings are in parallel and in phase, so 115V is required - i.e. ideal for the countries with 115V mains (e.g. USA). Any other connection is not permitted since it will involve connecting the windings 180° out of phase, so they'll approximately cancel and you'll get nothing.
Quote:
Originally Posted by
crossleymarko
also on the description ie. 500va 0-35 0-35.
does this mean its 70v output.
If you put the two secondary windings in series then yes you would get 70V, however we want them in parallel to get 35V at twice the current as if they were in series. Most transformers are wound with at least two secondaries to give you this option.