P\S Options

[Trentec]

I have a couple of options to choose from and was hoping someone could help me choose the best of the two. I have read the switchers are not "ideal" for stepper drivers but I have these IOTA DLS-30 units available (12V 30A, Ripple and Noise = <50 mV rms) I know 30A is overkill and series wiring may work isolating one of the chassis grounds. But is not something I am comfortable with as these are not dirt cheap units. The second is two old battery charger transformers 12V 6A and from what I have read this would be a better option. Ok heres the but, they seem to have a center tap with one diode (half wave I assume) and I need to know if in series how these diodes will affect the output and where to place the other two diodes or can I just put the outputs through a full wave Br Rec I have already? I would love to just get rid of the existing diodes so this would be easier for me to understand if thats possible can I just jumper where the diode is and remove it?

Also if it matters I plan on using the Zylotek drives and motors. Because as much as I would love to try and build my own drivers overall success is something I would like to achieve with as little singed hair as possible!

Thanks in advance

[NC Cams]

Read the following first:

Daisychaining ATX power supplies:

http://www.cnczone.com/forums/showth...015#post142015

http://forums.bit-tech.net/showthread.php?t=108208

Linear P/S design/construction
http://www.campbelldesigns.com/files...ply-part-1.pdf

How to properly phase a transformer in linear p/s:
http://cnczone.com/forums/showthread.php?t=14821&page1

Servo amp P/S design
http://www.elecdesign.com/Articles/A...7635/7635.html

Servo motor , servo amp, powersupply sizing for CNC
http://www.rutex.com/pdf/Mystique2.pdf

[Al_The_Man]

What you need to figure out is what the transformer has for secondary outputs (AC) , measure the outer ends and to centre tap, ignore the rectifier for now or remove it.
And then we can advise from there.
Al.

[Trentec]

I will wire one of these after work tonight and measure the outputs until then I can tell you that they are still wired in the chargers and the outputs are as follows, the far left (single coil lead) gives 6V 2A the center tap is common, second to left and first right of center gives 12V 2A and the right of center alone is 12V 6A what appeared to be a fourth tap is just the other end of the resister or diode hard to tell because it is wrapped in the insulation. The other odd thing is that it has three inputs the first ac input goes to a breaker then to a shunt the two black trans leads are connected to the shunt. The other ac lead goes through the ammeter then to the white lead of the transformer. I thought the shunt was for the ammeter but now Im confused.

1 2 3 4 5
6V2A 12V 2A 12V 6A common
single Double connected to double
coil lead coil 5 via diode or coil lead
lead resistor common
to all outputs
(single coil lead)

I also have a much simpler 12V 15 A transformer and I think I can get another. The reason I wanted to use the ones above is because I have seven of them all identical so replacement parts would be on hand.

[Trentec]

sorry the above needs correction terminals as listed give the rated voltage with the common they are not combined. sorry the switch was mis-leading. I promise not to post any more replies until I am wide awake!

[Trentec]

eek the diagram above got condensed and is now useless so I will give my latest revelation the outputs are inputs and the inputs are outputs...lol all the leads were cut off long ago for use as 12V power supplys by someone else. Although the DC ammeter on the AC side and the green ground wire running down the middle of my po neg leads should have been a clue!! Dont worry this is why I poke prod and ask questions before adding AC...! but this does place the unknown resistor or diode on the input side and the shunt on the output side still not feeding the ammeter. Can I just leave them wired as is switch selectable and all (in series) by-pass the shunts and use my Bridge rectifier giving 24V 6A? or do I have to use the 24 X 1.4 =33.6 to determine the voltage in this case? and yes the power supply provided by the vendor is looking cheaper by the minute.

[Al_The_Man]

Not really sure what you have there!
Once you rectify and add capacitors, you have to apply the 1.414 multiplier to the AC.
Al.

[Trentec]

Hope these help.

[Al_The_Man]

Still not clear on the secondary side, I suggest pulling the leads off the secondary and measuring resistance to see how many windings and what is centre tapped etc, also do a A AC voltage check when unconnected, did you identify the device in the lower right with the three transformer leads on? rectifiers ? Or is that the range switch?
Al.

[NC Cams]

Trentec = you have a multipurposed tranformer that shares a common core with multimle secondary windings. Via this design, they effectively generate multiple voltages with distinctly different current capacities from a common set of primary windings.

Although you can start to rehook the secondaries up in series to gain higher voltage, you're still goint to be limited to the current output of the LOWEST current capacity secondary winding once you hook them together.

If you have multiple idential transformers, I'd consider hooking up the high current simillar windings in series to gain the higher voltage you need. Hooking up the 12 amp phase to a 2 amp phase to get the desired total voltage is NOT adviseable.

Better yet, you really should draw up a schematic ala what Jerry the Fly Guy did. He learned a lot from doing it. It is simply FAR TOO EASY to get confused by simply hooking up wires, expecially if you don't have a logical plan/schematic to follow. To do the schamtic, you'll have to draw up a transformer. Once you "see" how the windings work and trace them out with a VOM, it is much easier to figure out what needs to be hooked where.

[Al_The_Man]

I think I may have interpreted wrong, I took it the RH side was the secondary, but looking again it could be the primary?
If this is correct then you have a full wave centre tapped supply.
I think you need to add a bit more info!!
Al.

[Trentec]

The seletor switch is on the right and the shunt\breaker is on the left. I am still not 100% positive about which side is the primary input my suspision is that the AC input is on the right side and the shunt is used for rectification if so I can easily series these without rewiring. I also have a larger simpler 12V 15A two inny two outy and I can aquire another, would 15A be too much with proper fusing? I also read that I cannot get a correct reading of the outputs with an ordinary multi-meter is this true and if so how do I measure? I have decided to purchase the power supply for the steppers from the vendor because frankly as you can tell I'm dangerous with electronics! But this is not in vain as I am going to build this supply for learning purposes and your input is greatly appreciated I have some work to do getting the measurements suggested and I will get some pics of the larger transformers.

Thanks again