[R-390] Role of the 3TF7 in PTO frequency changes

[sigmapert]

Hi David,

THX for another NON-OT msg.

You are right that the main component is a high frequency high
efficiency (95%) switching voltage regulator. The output is pure DC.
Maximum ripple & noise is 30mVpp.

Thorough testings (e.g. using a network analyzer) showed no signs of
spurious harmonics of the switching frequency in the receiver.

Kurt Schmid

> I offered a similar plug-in replacement (proudly
> named the "3DW7" after my initials) a few
> years ago and was mostly ignored.  My design
> does not need grounding.  I regulate RMS current
> (necessary to avoid the ground pin) by switching
> individual cycles of AC.  I figure that Kurt
> rectifies, and then regulates the output with
> a high-frequency switcher.  This has been done
> before, but not in a 3TF7-size package.  Is your
> output smooth DC, Kurt, or pulsating DC whose
> RMS value is 12.6?

> Dave Wise