Peter Baxandall's 1959 Class-D oscillator paper.

[Bill Sloman]

This has been available on my web-site for a couple of years.

The web-site has moved to Australia and the URL has changed in the process.

The new URL for the scanned image of the paper is

http://sophia-elektronica.com/0344_001_Baxandal.pdf

It has been posted with permission from the UK IEE who own the copyright, as noted here

http://sophia-elektronica.com/Baxandall_parallel-resonant_Class-D_oscillator1.htm

This web-page is missing it's graphical images, which is a bit odd. I spent a tedious afternoon correcting the relevant file-names so they displayed properly on the new IP's dummy web-site.

It will get fixed eventually.

 

[piglet]

Interesting, thanks, but isn't that a confusing use of the term *class D* which is nowadays regarded as something quite different? I think naming this a *current-fed push-pull convertor* would describe it clearly to a modern audience.

 

[Phil Allison]

"piglet"

Interesting, thanks, but isn't that a confusing use of
the term *class D* which is nowadays regarded
as something quite different?

** The first PWM amplifier was produced in 1964, the notorious Sinclair
-10 - but AFAIK Clive never described it as being "class D".

Anyhow, still long after Peter Baxandall's clever sine wave oscillator was
published.

I think naming this a *current-fed push-pull convertor*
would describe it clearly to a modern audience.

** Fraid the original name is bound to stick:

Baxandall "class D" sine wave oscillator.



..... Phil

 

[Bill Sloman]

Interesting, thanks, but isn't that a confusing use of the term *class D*which is nowadays regarded as something quite different? I think naming this a *current-fed push-pull convertor* would describe it clearly to a modern audience.

It's what Peter Baxandall called his circuit in 1959. Nobody in the US everseems to have read his paper, so the term has been used to describe other circuits since then, not all that consistently.

It's certainly a current-fed inverter, but "push-pull" is a bit specific.The parallel version, which is the more popular one, in part thanks to Jim Williams (who described it as a current-fed Royer inverter, which is nuts), is pull-pull (or push-push with PNP transistors or PMOS FETs). The serial version could be described as push-pull.