Re: Photodiode amplifier noise


On Mon, 04 May 2009 14:39:37 -0400, Phil Hobbs
<pcdhSpamMeSenseless@xxxxxxxxxxxxxxxxxx> wrote:

Jim Thompson wrote:
On Mon, 04 May 2009 13:01:10 -0400, Phil Hobbs
<pcdhSpamMeSenseless@xxxxxxxxxxxxxxxxxx> wrote:

Jim Thompson wrote:
[snip]
Absolutely! I was a circuit designer _before_ I trotted off to MIT.
The education only honed my capabilities.

...Jim Thompson
Ditto. Except that I never took a circuits course. ;)

I had ONE course in transistors... Germanium... how to bias without
thermal run-away ;-)

You didn't have a course in passive circuit theory and analysis?

The difference between an art and a science is that in science the
answer is out there waiting to be found, and we can all agree when we
find it (at least after all the people emotionally invested in incorrect
positions have decently died off).

Like AGW ?:-)

In an art, there are different ways of doing things that are more or
less equally good, it's unclear whether there's really a single best
answer, and the results depend a lot on the personality of the artist.
Not all valid questions are scientific ones, by a long shot.

By these definitions, troubleshooting is a science and design is an art.

Cheers

Phil Hobbs

I'm not sure about your last statement. I tend to think in a language
called "circuits", so I'm really good at debugging... even by remote.
Ask the Stheno guys ;-)

...Jim Thompson


I had part of a class in RLC circuits that I could have taught, but
that's all. The rest I learned from poring over the ARRL Handbook, and
(especially) databooks and app notes. Plus blowing up stuff, and not
chasing girls till I got to be 18 or so. ;)

I could always multi-task ;-)


The main thing that helped was the math, and lots of practice at home.
I got put in charge of all the TX side timing and frequency control on
the world's first direct-broadcast satellite system, two months after
getting my astronomy bachelor's degree (June 1981). (It was the
Spacetel system from AEL Microtel--They really needed people, and I got
insanely lucky.) I'd never built a PLL in my life, but it all
eventually worked fine. That was where I really learned to use a lot of
algebra when designing circuits.

I did have a really good undergraduate class on astronomical instruments
(Astronomy 421, taught by the estimable Professor Gordon Walker), which
is partly where I got my interest in electro-optics. Gordon is a great guy.


I don't think that it's impossible to be good at both design and
troubleshooting, though debugging is partly t'one and partly t'other.
(Michelangelo was a famous fortress expert, f'rinstance.)

Cheers

Phil Hobbs

Math _is_ very important. I _did_ start out my career doing a
complete Algebraic analysis of an OpAmp. Now-a-days I can usually
"see" those solutions, rather than having to crank out each and every
one, though occasionally I have a complex multivariable situation that
brings me back to pencil-and-paper.... like the dB linear gain control
for a sonar, compensated over temperature, power supply voltage, and
process corners... posted here a few years ago to taunt those claiming
they understood... I couldn't get a single taker who could analyze it
;-)

...Jim Thompson
--
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