Toroidal transformer hook up??? from China Help

[tubefrk]

I have a toroidal trns formor made in China, I cant figure out how to hook it up to the power supply. It was sold as a kit,it has variable voltages, the hook up chart, (If you can call it that) may as well be in chineeess. Can anyone Help?? thanks , Mike

[Paul Joppa]

The first step is to identify the leads on the transformer - how many windings are there, how many taps does each one have, and what is the resistance between taps and the total resistance of each winding. You can do this with an ohmmeter, if the documentation is not helpful. By the time you have done this, the documentation may make more sense.

[Grainger49]

Just sit down with a cold drink and pick a lead.  Measure resistance to every other lead and write them down.  Then go to the next lead and measure to all but the first, write them down.

What will happen is you will find some are wired together, have a resistance between each other.  These are one winding.  Once you have windings identified, the largest resistances are end to end, any others are taps on that winding.  Say you have four leads that have resistances of 2 ohms, 4 ohms and 6 ohms.  The 2 and 4 are intermediate taps and the end to end is the 6 ohm reading.  (The readings will never be that even)

[4krow]

While we are on the subject of torrids, should there be a resistor to ground on the primary side of the transformer? I have seen this, but don't understand it's purpose.

[Grainger49]

I can't say that I see a reason for a resistor to ground on the primary.  That would just raise the current through the hot leg, getting the fuse closer to blowing.

[tubefrk]

Thank you Grainger for you'r get back, if I can figure out what you said to do I'll give it a try. Not to smart with the electronics.     Mike

[Grainger49]

Mike,

Tell me how many leads it has on it and what color, I can explain better.