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

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


There probably _is_ a standard, but it was probably devised by some
committee of cretins sitting for the IEEE, so it's generally ignored.

The schematic representation doesn't matter anyway.

What matters is how the "template" for the part is seen by the
simulator, for instance...

Schematic Simulator

U1 X_U1
A1 X_A1

etc... ("parts" are either devices, Q, R, L, C, M, D... or
subcircuits, X...)

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine Sometimes I even put it in the food

"gore"

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.


** Like many things in the wide world of electronics, there are common
conventions that apply but no universal standard exists.

So folk in different places and in various companies do what seems logical
to them.




...... Phil

"gore" wrote in message
...
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.

U is quite common for ICs. X ought to be a crystal, typically. IC1 is
probably from some smaller design house where they're making up their own
standard as they go along (they probably also use, e.g., LED1...).

There is no universal standard, although growing companies often decide at
some point to go out and review some documented choices, such as what the IPC
recommends.

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

Q = transistor

D = diode (CR is archaic)

T = transformer

L = inductor

A = assembly

R = resistor (all kinds)

C = capacitor (ditto)

P, J are connectors

B = battery

F = fuse

K = relay

S = switch

V = tube


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


John

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


The standard reference designator for integrated circuits is "U" -
anything else is wrong! ( IMHO :-) )


--
Peter Bennett, VE7CEI
peterbb4 (at) interchange.ubc.ca
GPS and NMEA info: http://vancouver-webpages.com/peter
Vancouver Power Squadron: http://vancouver.powersquadron.ca

"John Larkin" wrote in
message

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

CR is still common. Is that supposed to be "controlled rectifier" (like in
SCR)?

Speaking of which, what do you use for SCR's and triacs?


--

Reply in group, but if emailing add one more
zero, and remove the last word.

On Fri, 5 Dec 2008 22:11:43 -0500, "Tom Del Rosso"
wrote:


"John Larkin" wrote in
message

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

CR is still common. Is that supposed to be "controlled rectifier" (like in
SCR)?

It was "crystal rectifier", and D was "dynamotor". You don't see many
surface-mount dynamotors [1] any more, so lots of people have swiped D
for diodes.

These designators are the classic military ones.


Speaking of which, what do you use for SCR's and triacs?

Q.

John

[1] a dynamotor is a rotating dc-dc converter.

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.

X should be a crystal.
A would be an amplifier (I haven't ever seen that btw)
IC is self-explanatory and is widely used in Europe
U is some weird US practice. U for what ? Rumour has it that it meant
'unknown'.

Graham

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

Peter Bennett 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.

The standard reference designator for integrated circuits is "U" -
anything else is wrong! ( IMHO :-) )

And what does U stand for ? Probably the stupidest choice ever aside from Q.

Graham

Tom Del Rosso wrote:

"John Larkin" wrote in

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

CR is still common. Is that supposed to be "controlled rectifier" (like in
SCR)?

Speaking of which, what do you use for SCR's and triacs?

SCR. Since a Triac is bilateral SCR, you could presumably use that too.

I also forgot LD or LED = light emitting diode.

Graham

John Larkin wrote:

"Tom Del Rosso" wrote:
"John Larkin" wrote

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

CR is still common. Is that supposed to be "controlled rectifier" (like in
SCR)?

It was "crystal rectifier", and D was "dynamotor". You don't see many
surface-mount dynamotors [1] any more, so lots of people have swiped D
for diodes.

These designators are the classic military ones.

In the USA !

Graham

Eeyore wrote:

John Larkin wrote:

"Tom Del Rosso" wrote:
"John Larkin" wrote

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

CR is still common. Is that supposed to be "controlled rectifier" (like in
SCR)?

It was "crystal rectifier", and D was "dynamotor". You don't see many
surface-mount dynamotors [1] any more, so lots of people have swiped D
for diodes.

These designators are the classic military ones.

In the USA !


Of course in the USA. America has built most of the military
electronics that have been used, since the start of WW-II. We can't
leave a task like that to amateurs, and idiots.


--
http://improve-usenet.org/index.html

aioe.org, Goggle Groups, and Web TV users must request to be white
listed, or I will not see your messages.

If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm


There are two kinds of people on this earth:
The crazy, and the insane.
The first sign of insanity is denying that you're crazy.

Eeyore wrote:

Tom Del Rosso wrote:

"John Larkin" wrote in

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

CR is still common. Is that supposed to be "controlled rectifier" (like in
SCR)?

Speaking of which, what do you use for SCR's and triacs?

SCR. Since a Triac is bilateral SCR, you could presumably use that too.

I also forgot LD or LED = light emitting diode.


No, LED = Lie Emmiting Donkey.

--
http://improve-usenet.org/index.html

aioe.org, Goggle Groups, and Web TV users must request to be white
listed, or I will not see your messages.

If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm


There are two kinds of people on this earth:
The crazy, and the insane.
The first sign of insanity is denying that you're crazy.

Eeyore wrote:

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 ?

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.



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

Also RT = thermistor.

Graham


--
http://improve-usenet.org/index.html

aioe.org, Goggle Groups, and Web TV users must request to be white
listed, or I will not see your messages.

If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm


There are two kinds of people on this earth:
The crazy, and the insane.
The first sign of insanity is denying that you're crazy.

Eeyore wrote:

Peter Bennett 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.

The standard reference designator for integrated circuits is "U" -
anything else is wrong! ( IMHO :-) )

And what does U stand for ? Probably the stupidest choice ever aside from Q.


Sigh. Do ANY of your neurons work? It was another available letter,
and used to identify the 'Unique' integrated circuits.


--
http://improve-usenet.org/index.html

aioe.org, Goggle Groups, and Web TV users must request to be white
listed, or I will not see your messages.

If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm


There are two kinds of people on this earth:
The crazy, and the insane.
The first sign of insanity is denying that you're crazy.

Eeyore 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.

X should be a crystal.
A would be an amplifier (I haven't ever seen that btw)
IC is self-explanatory and is widely used in Europe
U is some weird US practice. U for what ? Rumour has it that it meant
'unknown'.


Only outside the USA, by know nothing 'experts'.

--
http://improve-usenet.org/index.html

aioe.org, Goggle Groups, and Web TV users must request to be white
listed, or I will not see your messages.

If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm


There are two kinds of people on this earth:
The crazy, and the insane.
The first sign of insanity is denying that you're crazy.

"Michael A. Terrell" wrote:

Eeyore wrote:
John Larkin wrote:
"Tom Del Rosso" wrote:
"John Larkin" wrote

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

CR is still common. Is that supposed to be "controlled rectifier" (like in
SCR)?

It was "crystal rectifier", and D was "dynamotor". You don't see many
surface-mount dynamotors [1] any more, so lots of people have swiped D
for diodes.

These designators are the classic military ones.

In the USA !

Of course in the USA. America has built most of the military
electronics that have been used, since the start of WW-II. We can't
leave a task like that to amateurs, and idiots.

Actually, you simply copied many British designs.

Graham

"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 ?

Graham

"Michael A. Terrell" wrote:

Eeyore wrote:
Peter Bennett 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.

The standard reference designator for integrated circuits is "U" -
anything else is wrong! ( IMHO :-) )

And what does U stand for ? Probably the stupidest choice ever aside from Q.

Sigh. Do ANY of your neurons work? It was another available letter,
and used to identify the 'Unique' integrated circuits.

Again, what a stupid answer.

Graham

"Michael A. Terrell" wrote:

Eeyore 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.

X should be a crystal.
A would be an amplifier (I haven't ever seen that btw)
IC is self-explanatory and is widely used in Europe
U is some weird US practice. U for what ? Rumour has it that it meant
'unknown'.

Only outside the USA, by know nothing 'experts'.

The USA represents 5% of the world population.

Graham

On Sat, 06 Dec 2008 08:17:33 +0000, Eeyore
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.

X should be a crystal.

---
No, a crystal is designated with a 'Y'.

What you're probably thinking about is the abbreviation for 'crystal',
'XTAL'.
---

A would be an amplifier (I haven't ever seen that btw)

---
Then how would you know?

Anyway, it's not for 'amplifier, it's for 'assembly'.
---

IC is self-explanatory and is widely used in Europe
U is some weird US practice. U for what ?

---
Unit.

JF

On Sat, 06 Dec 2008 08:27:06 +0000, Eeyore
wrote:



Peter Bennett 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.

The standard reference designator for integrated circuits is "U" -
anything else is wrong! ( IMHO :-) )

And what does U stand for ?

---
Unit.
---

Probably the stupidest choice ever aside from Q.

---
No doubt the likes of you would have used 'T'.

JF

On Sat, 06 Dec 2008 08:29:53 +0000, Eeyore
wrote:



John Larkin wrote:

"Tom Del Rosso" wrote:
"John Larkin" wrote

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

CR is still common. Is that supposed to be "controlled rectifier" (like in
SCR)?

It was "crystal rectifier", and D was "dynamotor". You don't see many
surface-mount dynamotors [1] any more, so lots of people have swiped D
for diodes.

These designators are the classic military ones.

In the USA !

---
Well, no ****, Sherlock?

JF

On Sat, 06 Dec 2008 08:27:06 +0000, Eeyore
wrote:



Peter Bennett 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.

The standard reference designator for integrated circuits is "U" -
anything else is wrong! ( IMHO :-) )

And what does U stand for ? Probably the stupidest choice ever aside from Q.

Graham

Perhaps U = Unit?


--
Peter Bennett, VE7CEI
peterbb4 (at) interchange.ubc.ca
GPS and NMEA info: http://vancouver-webpages.com/peter
Vancouver Power Squadron: http://vancouver.powersquadron.ca

On Sat, 06 Dec 2008 11:09:39 -0600, John Fields
wrote:

On Sat, 06 Dec 2008 08:17:33 +0000, Eeyore
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.

X should be a crystal.

---
No, a crystal is designated with a 'Y'.

What you're probably thinking about is the abbreviation for 'crystal',
'XTAL'.
---

A would be an amplifier (I haven't ever seen that btw)

---
Then how would you know?

Anyway, it's not for 'amplifier, it's for 'assembly'.
---

IC is self-explanatory and is widely used in Europe
U is some weird US practice. U for what ?

---
Unit.

JF

HB: Hierarchical Block ;-)

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine Sometimes I even put it in the food

John Fields wrote:

Eeyore 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.

X should be a crystal.

---
No, a crystal is designated with a 'Y'.

What you're probably thinking about is the abbreviation for 'crystal',
'XTAL'.

You won't see any Y crystals in Europe IME.


A would be an amplifier (I haven't ever seen that btw)

---
Then how would you know?

Anyway, it's not for 'amplifier, it's for 'assembly'.

Which is hardly a pcb component is it ?


IC is self-explanatory and is widely used in Europe
U is some weird US practice. U for what ?
---
Unit.

Terrell disagrees. I have now heard explanations of Unknown, Unique and Unit !

IC otoh is 100% unambiguous.

Graham

On Sat, 06 Dec 2008 16:02:24 +0000, 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?


JF

On Sat, 06 Dec 2008 04:19:03 -0500, "Michael A. Terrell"
wrote:


Eeyore wrote:

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 ?

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.



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

Also RT = thermistor.

Graham

I justify my use of mil-std reference designators by the fact that
using arbitrary junk would convince my scientific and aerospace
customers that I'm an amateur who is ignorant of industry standards. I
really wouldn't want that to happen.

You may as well scatter parts around on a layout at odd arbitrary
angles, or use florid gothic script on orange front panels. Or invent
your own revision and ECO standards. Mount heatsinks with duct tape.
Send any messages you like.

John

John Fields wrote:

Eeyore wrote:
Peter Bennett 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.

The standard reference designator for integrated circuits is "U" -
anything else is wrong! ( IMHO :-) )

And what does U stand for ?

---
Unit.
---

Probably the stupidest choice ever aside from Q.

---
No doubt the likes of you would have used 'T'.

TR for TRansistor. He's the famous Quad 405 amplifier. The 'current dumper'.
http://www.geocities.com/ResearchTri...ad405cirb.html

Graham

On Fri, 05 Dec 2008 18:48:53 -0800, Peter Bennett
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


The standard reference designator for integrated circuits is "U" -
anything else is wrong! ( IMHO :-) )

It's certainly non-standard. I suppose you could make up your own
letters to represent the elements in a chemistry reaction, on the
theory that things like Sn and Pb are illogical.

But it would be tricky to get that published.

John

Peter Bennett wrote:

Eeyore wrote:
Peter Bennett 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.

The standard reference designator for integrated circuits is "U" -
anything else is wrong! ( IMHO :-) )

And what does U stand for ? Probably the stupidest choice ever aside from Q.

Perhaps U = Unit?

That's 2 votes for Unit and one for Unique so far in this thread. I have also
heard Unknown mentioned.

Graham

"Eeyore" wrote in message

John Fields wrote:

Eeyore wrote:
A would be an amplifier (I haven't ever seen that btw)

---
Then how would you know?

Anyway, it's not for 'amplifier, it's for 'assembly'.

Which is hardly a pcb component is it ?

Sure, it could be a smaller board.


IC is self-explanatory and is widely used in Europe
U is some weird US practice. U for what ?
---
Unit.

Terrell disagrees. I have now heard explanations of Unknown, Unique
and Unit !

IC otoh is 100% unambiguous.

U is 100% unambiguous too. It means IC.


--

Reply in group, but if emailing add one more
zero, and remove the last word.

John Fields wrote:

Eeyore wrote:

U is some weird US practice. U for what ?

---
Unit.

And if it's quad part ? QU ? Dual DU ?

Graham

Because I was already taken for an (I)ncandescent Lamp, and I was used
because L (Lamp) had been assigned to Inductor a great long time ago.

Similarly, T for Transistor was taken when Joseph Henry wound the first
(T)ransformer.

These two little rascals came along relatively late in the electronics game
and there weren't a lot of letters left.

It is left as an exercise for the student to list those letters that are not
assigned to any individual component (i.e. those still available for
assignment).

Jim

--
"It is the mark of an educated mind to be able to entertain a thought
without accepting it."
--Aristotle


"
And what does U stand for ? Probably the stupidest choice ever aside from
Q.

Graham

On Sat, 06 Dec 2008 09:16:03 -0800, Peter Bennett
wrote:

On Sat, 06 Dec 2008 08:27:06 +0000, Eeyore
wrote:



Peter Bennett 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.

The standard reference designator for integrated circuits is "U" -
anything else is wrong! ( IMHO :-) )

And what does U stand for ? Probably the stupidest choice ever aside from Q.

Graham

Perhaps U = Unit?

I think that was the origin. That's distinct from A, Assembly, which
has its own BOM. A Unit can not be disassembled.

Formal military systems often used nested designators: A3A6R41
uniquely located a resistor in a radar system. Some of the older HP
schematics used this convention, too.


John

On Sat, 06 Dec 2008 17:41:51 +0000, Eeyore
wrote:



John Fields wrote:

Eeyore wrote:

U is some weird US practice. U for what ?

---
Unit.

And if it's quad part ? QU ? Dual DU ?

Graham

U1A, U1B... U1F is how a hex inverter is labeled.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine Sometimes I even put it in the food

On Sat, 6 Dec 2008 09:45:19 -0800, "RST Engineering \(jw\)"
wrote:

Because I was already taken for an (I)ncandescent Lamp, and I was used
because L (Lamp) had been assigned to Inductor a great long time ago.

I recall lamps being DS.

John

On Sat, 06 Dec 2008 16:04:16 +0000, Eeyore
wrote:



"Michael A. Terrell" wrote:

Eeyore 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.

X should be a crystal.
A would be an amplifier (I haven't ever seen that btw)
IC is self-explanatory and is widely used in Europe
U is some weird US practice. U for what ? Rumour has it that it meant
'unknown'.

Only outside the USA, by know nothing 'experts'.

The USA represents 5% of the world population.

---
Yes, and never have so many owed so much to so few.

JF