[dude_500]

I can't find any information about the phase of the transformer in the documentation on the sigma-22. I'm ready to hook mine up and am wondering about the secondaries and their phase. I attached a picture of how the two phases could be wired, would I want option A or B?

I think option A makes sense based on my knowledge of AC but since I don't have any real training in AC theory I just want to make sure before I blow something up

 

[digger945]

"A" would be correct if your looking at the schematics for your particular transformer.
What kind of transformer are you using and do you have the secondary diagram?

Basically during one phase, you'll want the positive leg of one secondary attached to one extreme end, the negative leg of that secondary attached to the positive leg of the other secondary(these are connected together on the sigma board) and then the last leg attached to the last connector.

 

[MrMajestic2]

A would be correct. If the transformer is an Avel Lindberg then its Black, Red, Orange and Yellow going in that order or reverse into the S22 board.

 

[dude_500]

It's a Hammond toroidal but I do have the phase diagram so I can hook it up that way. Thanks for the verification on which way to configure it.

Would it be a good idea to first test on a variac or would that not work/be worse due to the design of the power supply?

 

[MrMajestic2]

Quote:

Originally Posted by dude_500 /img/forum/go_quote.gif It's a Hammond toroidal but I do have the phase diagram so I can hook it up that way. Thanks for the verification on which way to configure it. Would it be a good idea to first test on a variac or would that not work/be worse due to the design of the power supply?

I would go straight to hooking the toroid up. If its gonna blow, its gonna blow even with a variac

 

[dude_500]

Quote:

Originally Posted by MrMajestic2 /img/forum/go_quote.gif I would go straight to hooking the toroid up. If its gonna blow, its gonna blow even with a variac

I mean using both the torroid and the variac, put the variac at a very low voltage and then test to see if there are decimal dc volts at the output with the hopes that if there is a fault it will show up without damaging the components at full voltage... but I'm not sure if that would work or not as some power supplies won't operate at a lower-than-designed voltage such as a computer supply.

 

[MrMajestic2]

Quote:

Originally Posted by dude_500 /img/forum/go_quote.gif I mean using both the torroid and the variac, put the variac at a very low voltage and then test to see if there are decimal dc volts at the output with the hopes that if there is a fault it will show up without damaging the components at full voltage... but I'm not sure if that would work or not as some power supplies won't operate at a lower-than-designed voltage such as a computer supply.

I've never seen anyone do that and I don't thinks its a good idea either. The S22 is built for a certain output voltage and to achieve that you need a certain input voltage.

 

[digger945]

Also you need to be aware that the sigma 22 has zero current limiting.
Does you toroid not have a model number that can be looked up online?
If you could post the model number or a link or the diagram then we could help you to get it hooked up properly the first time.

Time would be better spent making sure that every component is in the correct place and mounted in the correct orientation and looking close with a loupe to make sure you don't have any cold joints or solder bridges.

 

[dude_500]

It is a hammond 182K30: Hammond Mfg. - Toroid Power Transformer - (182 Series)

I believe I should have Black/Brown and White/Orange on AC with sigma-22 socket being Red-Blue-Grey-Yellow

 

[Ferrari]

You have answered your own question.

Just connect your transformer as depicted on the diagram, showing at the Hammond website and you ar fine.