Using surplus power supplies

#1 Wed 29 November 2006, 15:20

I am wondering the viability of one of these units.

Agilent 6626A DC power supply

Does anyone here know whether this could be used for my MechMate project? Will these adapt to this type of CNC setup?
Would I be better advised to just get a constant source DC power supply.

I have found a source for several of these at an auction at greatly reduced prices from what they sold for new.

Ineed quick answers as I ony have about 24 hours left to bid if these might be a good choice. THANKS, Bob C.

#2 Wed 29 November 2006, 15:41

Bob,
I've never used, or even seen the Agilent 6626A DC power supply, but I did a quick Google search. It's not something that I could buy to run a CNC machine. The page that I saw lists the unit as having four outputs, two at 25 watts and two at 50 watts. That would work well in a lab where you needed high precision at low wattage. To drive steppers, you want high wattage without much regard for precision (assuming that a few volts is precise enough).

#3 Wed 29 November 2006, 15:59

Bob, Check out this guy. http://stores.ebay.com/Antek-inc_W0Q...3aUSQ3a3QQtZkm

#4 Wed 29 November 2006, 16:57

Thanks for your help so far. Please keep in mind I am electronicly "challenged", so most of the ideas I pose questions on are from be TOTAL lack of electrical knowledge. I am trying to learn the best and least expensive way to set up my Bot.

Regards,
bob C.

#5 Wed 29 November 2006, 22:10

How about this one and use both secondary windings in series ?:

http://www.toroid-transformer.com/AN-3225.pdf

$48 USD

#6 Tue 30 January 2007, 11:29

Vandeem,
That's similar to the one I use. The 23v+23v 400 VA.
You will gain 10% over his rating in the USA <-- Spec. says 20% This could approach Gecko's recommended limit of 80 volts or less.
I ended up with about 69.5 volts.
With that one you should end up with approx. 77 volts.
Sometimes you can buy from him through Ebay and save a few dollars.

DocTanner

#7 Tue 20 February 2007, 17:54

Doc, did you put the 2 primary windings in phase or out of phase with each other?

#8 Thu 22 February 2007, 10:26

James,
DisClaimer:
These things are dangerous.
Hire a licensed electrician.
Your surviving family will receive flowers for your funeral and nothing more from me.

At http://toroid-transformer.com there is a spec sheet for your tranformer. I assume you got yours there.
Typical of: say the AN-3222 300VA When you plug in both of the 120 volt side in, you will get 22 volts out 2 times
You can connect 1 green and one blue together, the other green and blue will be 44 volts. By the time you run it thru the rectifier and capacitor (Capacitor stores charge for extremely long time.)
you will end up with approx 66 volts dc.
I am not sure of the optimum voltage for the the motors and Geckos. I think several of us are running the same motors and perhaps it would be wise to ask Mariss at Gecko
Mine runs at 69 volts at one amp and no sign of getting warm. There may be some more power available, not sure it is needed. I need to find time to experiment.

DocTanner

#9 Tue 06 March 2007, 17:46

Gerald/ Anyone:

Would this unit be something that could be a substitute for building my own power supply as Gerald has provided plans for on this forum?

I have the ability to pick up one, or several of these New Old Stock never used from a local electronics company. I am unfamiliar with power supplies, and was wondering whether buying one of these would save me creating a home made power supply.

Any imput is greatly appreciated.

Bob C.

#10 Tue 06 March 2007, 21:10

Bob,
There are two things that you have to know about power supplies before you can determine whether a power supply is a good fit.

1. Does it provide the proper voltage?

2. Does it provide enough current?

The photo shows a laboratory power supply. Usually a laboratory power supply can be set to an exact voltage at a low to moderate current. Steppers like lots of current, compared to most electronic devices. The power supply that I'm using on my test bench as a stepper driver provides 10A. That might be more than necessary, but it works.

#11 Tue 06 March 2007, 22:10

I wish I had one of those! Overview, Data sheet.

The photo that you show is of a 3-phase supplied unit (3 input circuit breakers - do you have that?

But the number under the Voltage window seems to be TCR300S9 which is single phase according to the links above.

As Mike says, you have to know your stuff before considering this animal. You could easily end up adjusting the volume and colour of the smoke with the knobs provided.

#12 Fri 09 March 2007, 07:30

Gerald:

LOL the smoke and size of the cloud might fill my shop...

Am I correct in what I am picking up here, that you folks are building your power supply for around $80-$100 U.S. ?

can it be that inexpensive to put one together/

#13 Fri 09 March 2007, 07:55

Yes, we are building power supplies at well under $100. And they mostly work better than the fancy "regulated" versions because they don't complain about short overloads - they just ride the punches.

We make a big issue about how dangerous they are to build, because that is our duty. In reality, they are one of the easiest things to do when building your own CNC system.

#14 Fri 09 March 2007, 15:32

If you really want to pursue the surplus power supply option I would suggest looking for burnt out powerful amplifiers. I know some of them have toroid transformers dunno about the rest though, they might not be powerful enough and it would require the same skills as building one from scratch. On the other hand it might be a freebie and you and up saving $60-100...