Maker Pro
Maker Pro

Getting started with electronics? :)



Jan 1, 1970
On Tue, 24 Jan 2012 00:23:58 -0800 (PST), spamtrap1888

Do not be too quick to judge on that. Mostly learning it wrong first is
the real stumbling block rather than abstraction itself. Learning formal
abstraction is a different issue, and needs to be treated as such.
Where are the coulombs and joules in that drawing?

The best way to explain three new concepts is not by adding two more
new concepts.

Drilling down to bedrock is not always the best way to learn
something. As a kid, the current convention always bothered me,
because I knew current was a flow of electrons, and electrons went the
other way. Did current reflect a hole-centric way of looking at

But then I realized electrons were irrelevant to my study of current
flow. They're important to a deeper understanding of electronics, but
if you're not operating at that level they just get in the way.

What happened was merely an incorrect A|B choice long before there was
anything enough information to decide correctly. But it has been embedded
in the ASSumptions for hundreds of years and there is no reasonable way of
correcting it. Not that electrons move in conductors at anything like
light speed.



Jan 1, 1970
What do you mean by fundamental property? Resistance (more precisely,
resistivity) is a materials property

I could swear I recall deriving resistivity from the fundamental
properties of the material in question such as it's crystalline
structure, electron scattering cross-section, temperature, etc.
Quantum Thermodynamics or something. It was a very long time ago :)

Since neither "voltage" nor "current" are inherent properties of
materials, resistivity would seem, to me at least, be the more
"fundamental" property.

As an analogy, you can define mass as the ratio of applied force to
acceleration, but I think most people would say that mass continues to
exist in the absence of force and acceleration and hence is a
fundamental property.