Please Help Toroid Question for F1

[milezone]

Hello,

So I'm building a First Watt F1 and recently purchased this transformer: http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=TE60602-ND

I thought it fit the specifications however after some inspection I noticed that it seems to be missing a couple leads. The one I ordered has six leads however transformers in photographs of the amp appear to have around 8 or 9 leads. I'm concerned that I need to return the unit. Is what I'm describing a problem? Can it be alleviated with some modification? Please help!

 

[Redshift187]

Is it the 60602? It looks like it should have single primary designed for 117V (will work with 110V and 115V), and dual 18V secondaries. That would be 6 wires. The photos are not always exactly what you're ordering.

 

[milezone]

It is the 60602. I received it and it is six wires. My sense tells me that there should be more wires however (i.e. dual primary dual dual secondary). I assumed the F1 would use a single primary transformer but now I'm not sure upon looking at photos.

 

[Redshift187]

The number of primaries is irrelevant to the amp. If you are in the U.S. as your location flag tells me, the transformer will work. Dual primaries just makes a transformer work for most countries, 110V or 220V, as long as it was designed for both 50Hz and 60Hz.

 

[milezone]

I am in the US. Thanks for the assurance. I assume that means that I can leave the 240v input holes on the power filter pcb blank. Right...? Also shouldn't there be a ground lead as well?

 

[Redshift187]

Someone else should chime in, but looking at the service manual from the First Watt website, I would say connect the transformer to the spots marked 120A and 0A, then the thermistor between 0A and 0B. That would give you one thermistor in series with the transformer, the way it should be for a single 120V primary.

There is no ground on a dual secondary transformer, that's only on center-tap transformers. You may want to do a lot more reading about transformers and amp power supplies before attempting to build this. You don't want to make a mistake with the power supply.

 

[milezone]

Thank you for the help. I've done some research though I can't find much regarding the thermistor placement. I'm pretty sure the leads mount onto the power supply board however I've seen some more primitive uses (connecting them directly to the transformer wires. Any suggestions would be greatly appreciated.