[Amps] Switch-mode HV power supply

[ka1xo at juno.com]

The switch-mode power supply design has replaced the ferro-resonant transformer (Class-A) product used in the telecomms world. A rectifier putting out 100 amps at negative forty-eight volts weighed-in, let's say ten years ago, at roughly 300 pounds. 

A 100 amp switching module weighed thirty pounds five years ago, and the ones we are installing nowadays weigh twenty pounds apiece.

The solid-state devices need less heat-sink mass and there are fewer demandds for iron-core transformers and chokes. The newest modules are called ARGUS and they weigh about 23 pounds and put out a clean 100 amperes, DC at +24 or -48 volts.

However, the PA design for high power as discussed herein sounds redolent of the 5-tube AM receivers of forty years ago where one side of the a.c. line was directly connected to the chassis and the power plugs weren't polarized like they are today. I wouldn't want to be on a DXpedition using a switch mode amp with one side of the chassis possibly hot, in a tent, in the rain, etc., etc.!

Hal Mandel
KA1XO