Help with toroidal transformer

[CAM_MAN]

Could someone please help me out with the wiring of my transformer. I bought this transformer and didn't get any instructions with it. I got brave one night and sat down with my fluke meter and started measuring ouput voltages of the outputs on the transformer. I was assuming that I had it wired right when I was getting about 58 volts output. But now I am wondering if I actually have it wired right. The reason being is that I have smoked two G201's and blown several fuses. Also when it was running my motors they acted pretty erratic. They would go from running smooth to growling and missing steps but with no real heat buildup. Measured them with a laser temp and they never got over 120 degress F. The Geckos never got over 100 dgress F. I hate to admit that I am stumped but I am. Any how the specs on the transformer are 50V, 20 amps. There is a label on the transformer that has this wording on it.


I/P 0V -------------- 115V----------------230V

-------BLK----------- Red --------------Yellow

O/P 0V-----50V-------- 0V-----------50V

BLU--------BLU----------- GRN--------- GRN



There is a black, red and yellow input. There is two green outputs and two blue outputs. Now I was assuming that the black and red was the input for 115v and that is how I hooked it up. Now as far as the output goes I went with the two green because I was getting 58v from them. Could someone please help out a lost newbie and put him on the right track. I have a 4 x 8 router collecting dust because my electronics just aren't working.
Thanks.

[Al_The_Man]

As far as the primary is concerned if it is a centre tapped winding at 115v then it would not matter if you went from blk to red or red to yellow for the 115v input.
In any case hook up the primary first and check the secondary ac voltage on blu to blu and grn to grn if they are the same voltage on each they can be paralled up for double current rating, the only thing is they have to be phased right, they may have a marking on one blu and one of the grn wires.
The AC voltage you are getting on the secondary will be mulitplied by 1.414. -1.2v for a DC bridge rectifier supply with capacitance smoothing.
If you need help phasing the secondaries more help can be given, if the secondaries are different voltages then you cannot parallel them.
Al.

[CAM_MAN]

Hi Al.
I was hoping you would reply. I am using a 10000 MFD cap rated at 125V and my bridge is rated at 125V also. I am getting 78V coming off the cap. This kind of worried me because it is so close to the 80v rating on the G201's. It has been awhile since I did the voltage check on the transformer secondaries but if I remember correctly I think the voltage was the same on the two blue wires. And I remembered seeing a post about wiring in parallel and I tried that with some severe wire overheating. The transformer heated up like a waffle iron. So if there is a way to run them in parralel could you help me figure it out. Would this possibly help my motors from freaking out. I have 1200 oz in tormacs. Thanks.

[Al_The_Man]

To phase the secondaries, take ONE wire from each sec. and wire together, then measure the ac voltage on the two open ends, there should be close to zero voltage, if you get double the voltage of one sec. then swop one of the connected wires for the other of the same secondary.
When you have zero of the two open ends then they can be paralleld.
Al.

[CAM_MAN]

So you are saying to take one of the blue and one of the green and wire together. Then measure the voltage across the remaining blue and green wires. And if that doesn't read 0V swap green for green or blue for blue until I get 0V on the 2 open ends. Is that correct? Once I get there what do I do as far as connecting all four wires. I am a little confused on this, sorry.

[Al_The_Man]

I think you have it, once you get 0v across the two open ends, then these two open ends can be connected together , what you are doing is connecting both secondaries in parallel, one across the other so you end up with two connections with a blu and grn connected at each end.
When you tried before, you probabally had them connected this way but they were not phased properly.
BTW did you get this from the guy who sells them on ebay, as usually he marks the start winding of each secondary by a piece of black heat shrink.
Al.

[CAM_MAN]

Thanks alot Al. Yes the first time I tried connecting them in parallel I got the major heat thing and figured it was just not going to work that way so I gave it up. I purchased the transfomer and cap from Homeshopcnc and there was no marking on any of the wires. I'll give it a try sometime tomorrow. Thanks again.

[CAM_MAN]

Hey Al. The tip you gave me worked as I figured it would. The first set of wires I tied together did double the voltage then I swapped the green for green and ended up with 0V on the two open ends. So now with a blu green, blue green tied together I have 63 volts. So will that double my amperage output? So now running thru the bridge and the filter cap I have 88.7 volts. Will this be to much voltage for my Gecko G201's? I think this might be why I ahve smoked several drives already. I could have sworn when I first tested it I was only getting 78.5V. Is there any way to lower the voltage on the transformer. I would be a lot more comfortable if my filtered voltage was about 65V.