Regulated psu, do i need capacitors?

[Guldberg]

Im thinking of changing the toroidal transformer in my current project for a regulated powersupply. Would i still need the capacitors or are they built in to the unit?

It is a stepper system consisting of two 5.5amp motors. Right now i have a 24amp transformer with two giant capacitors. The regulated will be a 7.3amp, but as far as i have read a good rule of thumb for the calculating the need, is to time the motor ratings with 0.6: 5.5x2x0.6 = 6.6amp

[Al_The_Man]

Normally with a switching supply, you can use it up to the current capacity of the supply without extra capacitors.
1ph Linear supplies require to remove 100% ripple at 120hz, with switching supplies the frequency is much higher, therefore less need to use large cap. value smoothing.
Incidentally, why are you 'switching' over, linear supplies are generally more rugged and are easier to repair.
Al.

[Guldberg]

I think i changed my mind again. I just got tired of messing around with that big transformer. Also hate playing around with "high" voltage, so i liked the idea of just having a finished unit instead of that transforme/bridge/capacitor thing. A second thing is that the motors are rated at 5.5a/2.3v and the transformer is running at 60vdc which is just above the recomended 25times.

I just read through geckos stepper/motor basic guide, they suggest a unregulated supply and caps (why?), so i think ill just save the money and stick to what i got. Just have to fix it properly, its humming like hell right now:-)

[Al_The_Man]

Originally Posted by Guldberg I just read through geckos stepper/motor basic guide, they suggest a unregulated supply and caps (why?),

Probably because of the ruggedness issue and regulated is not really required for stepper/servo supply.

Originally Posted by Guldberg Just have to fix it properly, its humming like hell right now:-)

If the transformer is humming AND getting hot off load, then you have an overload somewhere, disconnect the load and try again, if it is not overheating, then it could be winding/lamination noise, but this is very rare on a Toroidal.
Al.