I'm a lawyer by profession, so that post was relatively short by my standards.

Sign seen in a lawyers office: Eschew Obfuscation

 

Sign seen in a lawyers office: Eschew Obfuscation

A rarely observed phenomenon in my profession.

 

A TO-3 can survive 23 watts, but attaching a heat sink can only make it more reliable.

What?
You must have missed a decimal point.
A TO-3 has a thermal resistance case-to-air of about 35°C/W, thus for a 25°C ambient and a 125°C maximum junction temperature, the absolute maximum allowed power dissipation would be 100/35 = 2.85W, so a value of 2.3W would be in the ball park.

The derating factor in converting from RMS transformer sine-wave current to rectified/capacitor output DC current is about 50%-60%. At that DC current level the pulsed RMS transformer current is approximately equal to the RMS current rating due to the high peak pulse nature of the current.
Thus the DC output should not be much more than 50% of the transformer RMS rating.

 

Yeah. Bad phrasing on my part. A TO-3 package can survive 23 watts, but you must attach a heat sink.

 

The max power dissipation happens when the output current hits the limit with minimum voltage drop over the regulator. That's when the output is shorted.

Power dissipated in this case is (23 - 0) x 1, or 23w.

That number divided by thermal resistance to ambient gives you the temperature rise.