Testing a Power Supply

[JerryFlyGuy]

Ok, so my Gecko's came yestarday [ Thanks Mariss & Crew] and I've got my steppers, and all the needed comp's for the power supply, and my B/o boards etc.. [ it's only taken me 3 months to accumulate and decide on all of this stuff so its a milestone ] Now, I'm concerned that I'm gonna build the power supply incorrectly and blow one of my Gecko's needlessly..

Is there a way to build and test my power supply w/out having to hook it up to the Gecko's and motor's? I'd like to be able to hook it up to something and then use my multimeter to check and make sure that the power level's are what I'd calculated them to be, that way I know what I'm dealing w/ before hooking my expensive electronic's up to it, that it will be ok. Would hooking it up to an old oven element or something be ok?

As always oppinion's welcome...

Jerry

[keebler303]

amps don't really matter as far as too little won't hurt the drivers and the geckos will only pull what they need so too much doesn't matter either. for the voltage you can just use a multimeter. for voltage under load hook up a load ( oven element, dc motor, string of light bulbs, you name it and check the voltage under load. if you hook up something big like an oven element you can also find the max current output of your supply.

[JerryFlyGuy]

Keebler, your a great help Another thing, the torid I'm going to use will need two 110 feeds in, these should be off two different household circuits right? Otherwise I'll overload my breaker at max amp's output?? I don't expect to see that for a while but... for now I'll most likely just use both from the same wall plug, simplify's it for just getting the motor's running, I'm hoping to get 220 into my garage come spring so then I'll just hook that and won't need the dual 110. I can't tell you what my power supply was supposed to output, that info is at home right now....

That all sound about right?

Jerry

[Al_The_Man]

NO, you should not run it off of two circuits for a couple of reasons, One you would have to make sure the supplies are on the same 120v leg otherwise you would have 2x120v out of phase with each other and blow the breakers, the other reason if one breaker trips the other could remain on.
They should either both be connected across the same 120 volt supply, windings in parallel or in series on 240v supply with a tandem breaker.
The first method involves the Neutral conductor, the second no neutral is used.
Al.

[keebler303]

your power supply woudl require some nuts to blow a standard 15a breaker. even if you are running at 60 volts you should get close to 30 amp output before you blow a breaker. i doubt you need that kind of power do you?

Matt

[Al_The_Man]

It is not so much the normal running current, With a high VA transformer the inrush current combined with the fact the PS capacitor charge appears momentarily as a short circuit during the charge time.
Fortunately most breakers have a time delay trip. But if fast blow fuses are fitted in the primary, this can cause nuisance blowing.
Al.

[keebler303]

so if thats the case then just put a 15 amp light dimmer on it and slowly bring it up to full juice. might be a pain but would alleviate the problem, as would a larger breaker and heavier wiring.

[JerryFlyGuy]

All good to know, I would have ended up putting it on two circuits and wrecking something even though I was trying to be extra carefull. I think the 220 re-wire is the way to go, best option. I went back and looked at my notes and the power supply is supposed to deliver 60v and up to about 20amp's so this should work pretty well w/ a parrellel setup off 1 , 110v line.

The power supply would HAVE to be hooked to something that uses power to properly test it right? I couldn't just that the leads out of the caps and screw them to two terminals and check the voltage across them ??

I think I know where and old oven element is so that would probably be best but.. thought I'd check.

Jerry

[smarbaga]

how many va are your transformers , and how much dc amps do u think u need to run these drives ?

[JerryFlyGuy]

Originally Posted by keebler303 so if thats the case then just put a 15 amp light dimmer on it and slowly bring it up to full juice. might be a pain but would alleviate the problem, as would a larger breaker and heavier wiring.

think I could use that as a load circuit? those dimmers work by resistance right? ... if so.. why don't they get hot [ that just poped into my head after asking this...] Ahh.... electricity just isn't my cup o' tea...

Jerry

[JerryFlyGuy]

Originally Posted by smarbaga how many va are your transformers , and how much dc amps do u think u need to run these drives ?

my torid is 1000VA I think [ I'd have to go dig it up], I'm running 4 drives w/ four steppers, all 6.3a @ 2.3v.

Jerry

[smarbaga]

most light dimmers use alternisters and a diac, a type of chopping transistor from techor,