Archive for category how-to
Vision response vs. Planck’s Black Body Curve
Posted by Michael Beach in application notes, how-to, math, metrology, optics, tech notes, technical articles on March 14th, 2009
Color temperature is based upon the idea of a Planck black-body radiator.
Here’s a Tech Note that shows how our eyes respond to the Planck Black-Body radiator.
For a lamp filament at a certain ‘color temperature’ there’s a curve of how our eyes
respond to the lamp. Pete put this into a MathCAD model, and there’s a pdf here
that shows off a few nice graphs.
attenuators, connectors, etc.
Posted by Michael Beach in how-to, parts, prototype, tech notes, tools, vendors on March 13th, 2009
Here’s where to get quality attenuators and connectors
Testing any high gain low noise amplifier requires a nice clean attenuator.
You need to drop the level of your function generator,
or that x1000 gain amp would need to supply 100 V output.
Pasternack Enterprisese sells a nice 30dB atten for about $42.
Their part number is PE7000-30.
If you put 2 of these in series, you have about x1000 attenuation.
(These assume a 50 Ohm load, so buy one of those too).
Here’s a link to their website:
http://www.pasternack.com/
Actinica Book List
Posted by Michael Beach in application notes, books we like, how-to, math, metrology, optics, research papers, tech notes on May 31st, 2008
Ok, we have a book problem.
Both of us waay like good engineering books. A good explanation, or a great
graph that sums up why that camera ‘sees’ differently than my eyes, etc.
Since we’re always stumbling on more good books, this list will grow.
Drop by later see what’s new.
Here’s some of the books we like, as a pdf file here,
and here’s some more books we like:
- the Feynman Lectures on Physics, a 3 volume set. Here’s a guy who can explain anything well. Like how sine, cosine and the magic number e all relate to the imaginary number i (square root of -1). He also has a great description of how a ’50 Ohm’ transmission line acts like ’50 Ohms’ no matter how long it is. For a really great puzzle – read his description of how charging a capacitor really involves magnetic fields outside the cap’s plates.