John Larkin wrote:

On Fri, 5 Dec 2008 19:33:40 -0500, "gore"
wrote:

I work at an electronics contract manufacturimg facility. We do work for
several companies and I wonder why they use different labels on the
schematics and pcb's to refer to IC's. Some of them have a U1, an A1, and
X1, or an IC1. Why do they do this? Is there a standard used to label IC's
in a schematic? Just curious why this is.

Thanks


U (IC) = IC

Q (TR) = transistor

D = diode (CR is archaic) (well at least we can agree on that. Why not U and
Q too whilst at it ?)

T (or TR or TX ) = transformer

L = inductor

A = assembly

R = resistor (all kinds)

RN = resistor network.


C = capacitor (ditto)

P, J (CN, CON, CONN, sometime J) are connectors

I prefer J for user selectable 'jumpers/headers' that take shorting links.


B = battery

F = fuse

K (RL, RLY) = relay

S (SW) = switch

V (V for valve) = tube

IC, CON, HDR, TR, VR, CHO, RN, RV, RLY, SW, LED and such are all
amateur inventions.

No they make vastly more sense. How can you justify the use of Q for a
transistor for example ? A quansistor ?

I also use CD = decoupling capacitor to distinguish from a capacitor 'in
circuit'.

Also RT = thermistor.

Graham