doubly bootstrapped photodiode circuit

[John Larkin]

Hey, Phil,

I was reading Burns' biography of Alan Blumlein and found this:

https://dl.dropbox.com/u/53724080/Circuits/Blumlein/Blumlein_1.JPG

https://dl.dropbox.com/u/53724080/Circuits/Blumlein/Blumlein_2.JPG


The photodiode here was actually the pickup plate of an Emitron TV
camera tube. This is from about 1935.

Blumlein was an interesting guy, one of the best EEs that ever lived.
He never learned to spell, was an atrocious writer (see above) and
didn't read very well, so his wife read aloud to him. He may have
saved England from starvation; Hitler credited his H2S radar for
sweeping the U-boats from the Atlantic. He was apparently fearless and
died in a plane crash, testing a radar, in June of 1942.

This guy patented the cathode follower and invented the long-tail
pair, the transversal filter, and the phantastron Miller ramp
generator.


--

John Larkin Highland Technology Inc
www.highlandtechnology.com jlarkin at highlandtechnology dot com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom timing and laser controllers
Photonics and fiberoptic TTL data links
VME analog, thermocouple, LVDT, synchro, tachometer
Multichannel arbitrary waveform generators

[Bill Sloman]

On Oct 15, 11:45 am, John Larkin

<jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
> Hey, Phil,
>
> I was reading Burns' biography of Alan Blumlein and found this:
>
> https://dl.dropbox.com/u/53724080/Circuits/Blumlein/Blumlein_1.JPG
>
> https://dl.dropbox.com/u/53724080/Circuits/Blumlein/Blumlein_2.JPG
>
> The photodiode here was actually the pickup plate of an Emitron TV
> camera tube. This is from about 1935.
>
> Blumlein was an interesting guy, one of the best EEs that ever lived.
> He never learned to spell, was an atrocious writer (see above) and
> didn't read very well, so his wife read aloud to him. He may have
> saved England from starvation; Hitler credited his H2S radar for
> sweeping the U-boats from the Atlantic. He was apparently fearless and
> died in a plane crash, testing a radar, in June of 1942.
>
> This guy patented the cathode follower and invented the long-tail
> pair, the transversal filter, and the phantastron Miller ramp
> generator.

Not to mention stereo recording, and a host of other things.

http://en.wikipedia.org/wiki/Alan_Blumlein

One of his colleague - William S.Percival was still working at EMI
Central Research when I was working there, and I got to meet him

http://en.wikipedia.org/wiki/Distributed_amplifier

--
Bill Sloman, Nijmegen

[John Walliker]

On Oct 15, 1:45 am, John Larkin
<jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
> ... Hitler credited his H2S radar for

> sweeping the U-boats from the Atlantic. He was apparently fearless and
> died in a plane crash, testing a radar, in June of 1942.

Don't forget, though that the H2S radar depended on the cavity
magnetron developed by Randall & Boot.

John

[Bill Sloman]

And most modern electronics despends on the transistor ...

--
Bill Sloman, Sydney

[Phil Hobbs]

On 10/14/2012 8:45 PM, John Larkin wrote:
>
> Hey, Phil,
>
> I was reading Burns' biography of Alan Blumlein and found this:
>
> https://dl.dropbox.com/u/53724080/Circuits/Blumlein/Blumlein_1.JPG
>
> https://dl.dropbox.com/u/53724080/Circuits/Blumlein/Blumlein_2.JPG
>
>
> The photodiode here was actually the pickup plate of an Emitron TV
> camera tube. This is from about 1935.
>
> Blumlein was an interesting guy, one of the best EEs that ever lived.
> He never learned to spell, was an atrocious writer (see above) and
> didn't read very well, so his wife read aloud to him. He may have
> saved England from starvation; Hitler credited his H2S radar for
> sweeping the U-boats from the Atlantic. He was apparently fearless and
> died in a plane crash, testing a radar, in June of 1942.
>
> This guy patented the cathode follower and invented the long-tail
> pair, the transversal filter, and the phantastron Miller ramp
> generator.

Cute, thanks. Bootstrapping is I think even older than that, having
been used to drive the shields on Asdic sets in the late 1920s. IIRC it
was called the 'phantom repeater'.

Blumlein was an interesting guy, and one I should probably know more
about than I do. Another guy of that sort was R. V. Jones, who invented
and ran British scientific intelligence during the war, and was the guy
who figured out how to beat the German navigation beam systems
(Knickebein and its successors). His book, "The Wizard War" (I forget
what the UK title is) should be on every engineer's shelf.

Having a screen grid is handy for bootstraps, but nowadays we can do the
same thing by bootstrapping the bootstrap, or (for low performance
tasks) using a dual-gate MOSFET.

I've been working on a trick to combine BF862s and pHEMTs to make
~400 pV/sqrt(Hz) bootstraps that work from near DC to ~2 GHz. Fun.
(You can't do that with a tetrode!)

Cheers

Phil Hobbs


--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510 USA
+1 845 480 2058

hobbs at electrooptical dot net
http://electrooptical.net

[Joerg]

... and then the financial folks learned from that but screwed it up. As
one of the guys at KFBK once said, they leveraged the leverage that was
already leveraged :-)

> I've been working on a trick to combine BF862s and pHEMTs to make
> ~400 pV/sqrt(Hz) bootstraps that work from near DC to ~2 GHz. Fun. (You
> can't do that with a tetrode!)
>

With the BF862 I'd have no supply worries right now but with pHEMTs you
might want to stash a reel in the nitrogen cabinet.

--
Regards, Joerg

http://www.analogconsultants.com/

[John Larkin]

There were two H2S versions, one klystron based. The magnetron version
was far better, with about 4x the range. The problem with the
magnetron is that it's practically indestructable, so if bombers flew
over Germany, it wouldn't be long until one crashed and the Germans
had a magnetron. That actually happened, pretty quickly, but the
Germans didn't capitalize on it. The decision to use the magnetron
version over Europe went to the highest levels of the British
government.

The klystron, invented by the Varian brothers, was still key, as the
receive LO.

It's astonishing that, not too long after the strapped cavity
magnetron was invented, they were making megawatt, 500ns pulses at S
and X band. Radar went from fuzzy blips to near photographic quality
in a few years.

Burns' biography is good. It doesn't skimp on the technical details,
and it's full of drawings and schematics. A great book about the
Varians (and pre-war California, and Stanford) is "The Inventor and
the Pilot", written by Russel Varian's widow. I have a signed copy!

[John Larkin]

Some things are nichey (sp?) enough that nobody will bother to
integrate them, so we have to make them out of parts. It is impressive
the sort of speeds you can get, putting small parts on PC boards.

>
>Cheers
>
>Phil Hobbs

The next time some amateur/lurker rags me about my spelling, or using
the wrong case letter when the meaning is obvious, all I have to say
is "Blumlein."

[Phil Hobbs]

Yup. If I ever go into the instruments business on my own, there'll be
a few things like that in there.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

[Bill Sloman]

> The next time some amateur/lurker rags me about my spelling, or using
> the wrong case letter when the meaning is obvious, all I have to say
> is "Blumlein."

You aren't dyslexic, and you aren't remotely in Blumlein's class (nor is
anybody else who posts here, so that really isn't an insult) so it isn't
going to work.

Like everybody else, you make "errors of action" aka typo's or
drop-offs, at an average rate of one every thirty minutes (unless you
are drunk, sick, over-tired, or distracted all of which raise the rate).

People can rag you about it, but it's a bit silly to bother.

--
Bill Sloman, Sydney