Toroidal trannie question

[Daniel Stover]

Hi there,

Newbie to the group, semi-newbie to electronics.

I'm building a tube mic and power supply. Rather than a single
transformer, it calls for two trannies with one backwards.

So when I go to mount them, should I mount them on the same plane, or
is is alright to stack them. Either way doesn't really matter as the
PSU boards aren't very big and i'll have plenty of room between them
and the trannies.

Mainly wanting to know out of curiousity and for future reference.

Thanks,
Daniel

 

[Kevin R]

On Fri, 02 Jul 2004 15:59:40 -0500, Daniel Stover <K.a.s.p.a.r.g.u.y@h.o.t.m.a.i.l.c.o.m>
wrote:

Hi there,

Newbie to the group, semi-newbie to electronics.

I'm building a tube mic and power supply. Rather than a single
transformer, it calls for two trannies with one backwards.

So when I go to mount them, should I mount them on the same plane, or
is is alright to stack them. Either way doesn't really matter as the
PSU boards aren't very big and i'll have plenty of room between them
and the trannies.

Mainly wanting to know out of curiousity and for future reference.

Thanks,
Daniel

I think it is probably better to avoid stacking them. I think the risk of the magnetic
field from one affecting the other is quite small, but it is a risk. But the main thing
is that you are reducing the surface area exposed to air and so it is less able to
dissipate heat.

One big thing to remember with toroidal tansformers is do not short the top end of the
bolt with which they are bolted down to the metalwork at the other end of the bolt or it
will constitue a shorted turn.
Also do not over tighten the bolt. I have seen this done on a number of occasions where
it has resulted in shorted turns.