[sdiy] transformer question

[Czech Martin]

Ok, torroids are nearly humless.
They have low stray inductance. This means they represent a 
very stiff voltage source, e.g. if you short them
you'll be sorry. They also tend to blow fuses when turning on.
For rectifiers with caps this means huge
peak currents, a lot of noise in the mains supply.
At least I think so. Ok, we can handle that and use a 
inductor coil to smooth that current. ANother component.

????

Wouldn't it make sense to use a transformer with a large stray
inductance in the first place. Ok, it will make stray fields,
but the turn on current and rectifier peak current will
behave. OTOH it has a soft characteristic, which means that
you need more voltage margin, leading to more regulator
drop/heat.

??

I'm not so sure that a torroid core is always a good choice
for a regulated dc supply.

Sure , it will make a difference where the inductance is placed,
before or behind the rectifier. Certainly not the same.
Have to think about that again...


m.c.