From PA0SE to All
Alan Melia wrote:
Hi all, I dug out a copy of an article by Nathan Sokal (Pres. of Design
Automation) that was published in Design Electronics on 20 Sept 1977 titled
"Class E can boost efficiency".
This turns out to be a very practical article with simple design formulae,
and a 'build it and play' circuit with example scope traces of current and
voltage waveforms. The test circuit is to run at 10 MHz but the detail
looks
eminently suited to 136kHz. Efficiencies of 82 to 95% are quoted for some
very ordinary transistors and FETs. There is no formula given for the RF
Choke but I think that can be scaled from the 10MHz value.
I know some have Class E stages already, but this may be a help to others
to
get the parameters right. It looks as though I no longer have the original
magazine, but it looks as though the copy I have will re-copy. Anyone
interested.......if there are too many, can anyone offer to scan it in?
Though there may be a copyright problem there even on a 22 year old
article.
I have a sneaking suspicion the gentleman is a Ham, though he didn't admit
to it in the corresponece I had with him in the late 70s or in the article.
I wonder if Andre knows?
In the meantime I'm willing to snail-mail copies (until the Bank Manager
objects)
Useful information on class D, E and F amplifiers with references to the
original articles can also be found in Technical Topics by G3VA in Radio
Communication of:
August 1997 p. 77
October 1996 p. 77
73, Dick, PA0SE
| 