[sdiy] How to predict a transformer's current capability?

[Jaco Sloof]

Hmm, gaps in the core...

This concerns me a little bit, because:

I'm still constructing my power supply, and 
the transformer HAS gaps, as in; mounting holes to screw it
to the chassis, THROUGH the core...

Is this Bad?
(hole diameter is 4.5 mm, that on each corner thus 4 holes...)

Rrrrr, i'm getting saturating shivers here, with lots a background
noise...

--- harry bissell <paia2720 at yahoo.com> wrote:
> You should be able to detect core saturation by
> watching the current very carefully... as saturation
> approaches the current increases very quickly... a
> knee
> similar to diode conduction (but going the other
> way...
> bigger!)
> 
> Another way is to use a "telephone pickup coil" to
> listen to the hum (flux leakage) around the
> transformer. When the core saturates, the magnetic
> field will grow in the air surrounding the core.
> 
> This will also identify transformers that by design
> or mistake, have substantial gaps in the core (usually
> a bad thing...)
> 
> H^) harry


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