On Mon, 06 Sep 2010 09:20:33 -0500, John Fields wrote:

On Mon, 06 Sep 2010 01:47:41 +0100, Eeyore
wrote:

Fred Abse wrote:
On Sat, 04 Sep 2010 07:56:51 +0100, Eeyore wrote:

Do please especially explain the relevance of the letter Q to indicate a
transistor or U for an IC.

No sillier than "L" for inductance, or "Z" for impedance, or "Y" for
admittance, or "B" for susceptance, or "G" for conductance.

What kind of equations do you use for calculating impedances ?

For example Z = 2.pi.f.L is a common one.

---
That's only true because:

Z = sqrt (R² + (Xl - Xc)²)

and it's the only circuit element being considered.

More correctly, 2pi f L is considered to be the "inductive reactance"
of an inductor, and the equation is written:

Xl = 2pi f L
---

L is clearly a well-understood 'shorthand' for inductance along with R
and C for resistance and capacitance.

I don't know of any components requiring designation on a schematic or
PCB that require defining by Y, B or G,

---
"Y" is the reference for any sort of resonator, but more particularly
for the ubiquitous quartz crystal resonator.

"B" is the reference designator for a blwer, motor, or synchro, and
"G" is the reference designator for, among other things, a generator.

Saw G1 for a overvoltage phone line protector (Gas discharge?) recently.

Grant.