Greetings!!!


Can a Toriod transformer be Glued to a heat sink??? The Toroid
will be JB welded to the heat sink.

The toroid will be wound with a 30 degree gap between the start of
the winding to the end of the windings the toroid will ( winding
gap) be glued at that that point vertical position the windings
will be about 1/4 inch above the heat sink.

Comments???

Thanks!!!

On Dec 27, 11:57*pm, wrote:
Greetings!!!

Can a Toriod * transformer be Glued to a heat sink??? * The *Toroid
will be JB welded to the heat sink.

The toroid will be wound *with a 30 degree gap *between the start of
the winding to the end of the windings * the toroid will ( winding
gap) *be glued at that that point *vertical position * the windings
will be about 1/4 inch above the heat sink.

Comments???

Thanks!!!

Ummm, not a good idea from my experience... I would be happier to see
a non metallic spacer between the toroid and the heat sink...

denny

On Dec 27, 8:57 pm, wrote:
Greetings!!!

Can a Toriod transformer be Glued to a heat sink??? The Toroid
will be JB welded to the heat sink.

The toroid will be wound with a 30 degree gap between the start of
the winding to the end of the windings the toroid will ( winding
gap) be glued at that that point vertical position the windings
will be about 1/4 inch above the heat sink.

Comments???

Thanks!!!

Is the toroid getting so hot that RTV will not work? If so, then you
have other problems. Toroids are not supposed to get hot! Most toroids
are attached to circuit boards with RTV. I have never seen one needing
a heat sink.

JB Weld is wonderful stuff, but will crack if subjected to stress or
vibration. If you still want to go ahead with this, you need to make a
rough surface on the toroid and the heat sink to give the JB Weld a
place to attach to.

Paul, KD7HB

On Dec 27, 8:57 pm, wrote:
Greetings!!!

Can a Toriod transformer be Glued to a heat sink??? The Toroid
will be JB welded to the heat sink.

The toroid will be wound with a 30 degree gap between the start of
the winding to the end of the windings the toroid will ( winding
gap) be glued at that that point vertical position the windings
will be about 1/4 inch above the heat sink.

Comments???

Thanks!!!

I certainly would prefer to use RTV since that allows for different
temperature expansion between the toroid and the mounting surface. Toroids
are rather brittle and need some amount of flex in the way they are mounted.

Jim Pennell
N6BIU


--

17:56 Pacific Time Zone
Dec 30 2007

International Time
01:56 UTC
31.12.2007

On Dec 27, 11:57*pm, wrote:
Greetings!!!

Can a Toriod * transformer be Glued to a heat sink??? * The *Toroid
will be JB welded to the heat sink.

The toroid will be wound *with a 30 degree gap *between the start of
the winding to the end of the windings * the toroid will ( winding
gap) *be glued at that that point *vertical position * the windings
will be about 1/4 inch above the heat sink.

Comments???

Are you trying to heat sink the transformer? That's a mistake. The
glue will be an insulator, not a conductor!

If you're just physically mounting it, a good stiff bolt running
through the center, with some rubber isolation, is how I always see it
done.

Tim.

Tim Shoppa wrote:

On Dec 27, 11:57*pm, wrote:
Greetings!!!

Can a Toriod * transformer be Glued to a heat sink??? * The *Toroid
will be JB welded to the heat sink.

The toroid will be wound *with a 30 degree gap *between the start of
the winding to the end of the windings * the toroid will ( winding
gap) *be glued at that that point *vertical position * the windings
will be about 1/4 inch above the heat sink.

Comments???

Are you trying to heat sink the transformer? That's a mistake. The
glue will be an insulator, not a conductor!

If you're just physically mounting it, a good stiff bolt running
through the center, with some rubber isolation, is how I always see it
done.
==================
A toroid carrying a RF signal should never get hot ......if it does there is
a serious design problem.

Frank KN6WH / GM0CSZ

I did not see the OP as being a heat issue, just a mechanical mounting
issue... THough toroids are more self shielding than than non toroids,
they are not perfect... Based on my experience with toroids in VFO's
being very close to a metal object does affect the inductance, I would
prefer to see him glue an insulator pad to the heat sink as a spacer
and then glue the toroid to that... IF he was in fact trying to
heatsink the toroid, he has major design problems he needs to solve..

denny / k8do

"Denny" wrote in message
...
I did not see the OP as being a heat issue, just a mechanical mounting
issue... THough toroids are more self shielding than than non toroids,
they are not perfect... Based on my experience with toroids in VFO's
being very close to a metal object does affect the inductance, I would
prefer to see him glue an insulator pad to the heat sink as a spacer
and then glue the toroid to that... IF he was in fact trying to
heatsink the toroid, he has major design problems he needs to solve..

denny / k8do

I agree. If the toroid is getting that hot. ie too hot to hold your finger
on it, then the core is under sized. A re-design is called for.