About using oversized transformer

[amb]

TimmyMac, I don't recommend a direct paralleling of the MOSFET like that. Each MOSFET should have its own gate resistor and source resistor. The two onboard MOSFETs per rail are set up that way.

 

[TimmyMac]

Quote:

Originally Posted by amb /img/forum/go_quote.gif TimmyMac, I don't recommend a direct paralleling of the MOSFET like that. Each MOSFET should have its own gate resistor and source resistor. The two onboard MOSFETs per rail are set up that way.

Oh, I see. I thought you meant that the MOSFETs could be paralleled on the existing boards. Guess it's back to many boards then.

 

[Navyblue]

Thanks for the great explanation AMB.

Btw I should have received those stuffs you sent me yesterday, but no one was home at the time and I'll have to collect them from the post office tomorrow. Thanks.

How about using two 2x15V transformers? Is there a way to do that? I know too little to know if it defies common sense.

 

[amb]

Quote:

Originally Posted by Navyblue /img/forum/go_quote.gif How about using two 2x15V transformers? Is there a way to do that? I know too little to know if it defies common sense.

Yes, you could do that. Just connect the two 15V secondaries on each transformer in series to make a single 30V one.

I gotta ask, though. Why go through so much trouble? 2x30V transformers in the 80VA range should not be difficult to source. People all over the world have built these amps with them...

 

[FallenAngel]

Except for it being more expensive than necessary, using 2 2x15 transformers should be possible if you connect the secondaries of each transformers in series and then you'll have essentially 2 1x30 transformers.

 

[Navyblue]

Quote:

Originally Posted by amb /img/forum/go_quote.gif Yes, you could do that. Just connect the two 15V secondaries on each transformer in series to make a single 30V one. I gotta ask, though. Why go through so much trouble? 2x30V transformers in the 80VA range should not be difficult to source. People all over the world have built these amps with them...

The lowest 2x30V I can get locally are the 63VA, the next step up would be the 160VA. I'd like to avoid importing as the shipping cost would be more than 100% of the cost of the transformer, which in my book isn't a fair price to pay. But now it looks like I gotta get one shipped from the US, as two 2x15V aren't cheap either. Or I'd have to go 2xS22.