John Fields wrote:

Eeyore wrote:
John Fields wrote:
Eeyore wrote:
"Michael A. Terrell" wrote:
Eeyore wrote:
John Larkin wrote:
"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 ?

It was justified by the fact that it was available. It doesn't need
any more justification for people who know what they are doing.

What a particularly STUPID response.

Why not E, H, N, P, W for example ? Or Z ?

---
'E' was being used for test points, 'P' for male (plug) connectors with
either male or female contacts, 'W' for wire harnesses or cables, and
'Z' for filters.

So out of 'H', 'N', and 'Q', 'Q' was chosen.

What gives you heartburn about that? That it wasn't you who got to
choose?

Sensible people use TP for test points. Connectors can be CN, CON or CONN.

---
Then, no doubt, you'd use 'FR' or something like that.
---

The only use of FR I know w.r.t. PCBs is 'fire retardant' as in FR-4.


Connectors can be CN, CON or CONN.

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They can be designated anything when left to the likes of you, but
they're usually designated 'PXXX' or 'JXXX' by people who know what
they're doing.

Not here. Another one is SKT (socket). I think BT (our equivalent of Bell) like that one.
I think they also use PL = plug.

You see using more than one letter makes it so much more descriptive and avoids all those
crazy miltiple allocations in your ANSI doc.

Graham