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


Respectfully disagree, John. I grew up in the era of the #47 pilot lamp
being ubiquitous in radio dial lighting in everything I worked on that
needed backlighting or pilot lights. (I) was the standard; I never once saw
DS.

Jim

We've developed one that works well for us. R1 is mounted on the cabinet or
chassis. R101 is on the first subassembly (generally a pcb), R201 on the
second subassembly, and so on. I've been asked what happens when you get
past the 9th subassembly and I reply that we are building small aircraft
electronic devices, not locomotives.

Jim

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

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.

Graham

On Sat, 06 Dec 2008 17:30:05 +0000, Eeyore
wrote:



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.

---
You will on stuff that we send there.
---

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 ?

---
It is if it's a subassembly, which is when the 'A' reference designation
is used.
---

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.

'unknown' and 'unique' are nonsensical. 'U' is not, and when seen on a
schematic unambiguously identifies the part.

Besides, since the integrated circuit was invented in the US, no doubt
the 'U' reference designator was too.

That, in and of itself, was probably enough to send you lot into a tizzy
and cause you to spend a lot of sleepless nights trying to come up with
something other than the NIH 'U'.

Typical.

JF

Tom Del Rosso wrote:

"Eeyore" wrote
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.

Why use another letter when you 2 that describe the part properly ?

Graham

Jim Thompson wrote:

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 ?

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

Not on a circuit board it isn't.

Graham

John Larkin wrote:

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.

LP here I think.

Graham

"RST Engineering (jw)" wrote:

We've developed one that works well for us. R1 is mounted on the cabinet or
chassis. R101 is on the first subassembly (generally a pcb), R201 on the
second subassembly, and so on. I've been asked what happens when you get
past the 9th subassembly and I reply that we are building small aircraft
electronic devices, not locomotives.

I've seen PCBs with R numbers 1000.

Graham

On Sat, 06 Dec 2008 17:39:59 +0000, Eeyore
wrote:



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.

---
Where?

JF

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 ?

Single part: U1

Dual part: U1A, U1B

Quad part: U1A, U1B, U1C, U1D

Easy, huh? BTW, I thought you said once upon a time that you were
conversant in ORCAD.

Have you totally forgotten everything?

JF

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

Graham


OK, I'm going to try and put a stop to this senseless bull**** badminton
game. Graham, point me to a page where you were the chief engineer on a
product that is on the market for sale. If you can, I'll continue the
discussion, but from what I've seen here, you've never had the
responsibility for a complete marketable product or you wouldn't be going on
and on about nonsensical reference designators.

95% of what I've designed over the last 50 years is obsolete and no longer
marketable, but for current products, please to go and see
www.rstengineering.com.



Jim

John Fields wrote:

Eeyore wrote:
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.

---
Where?

In one of the sci.electronics groups.

Graham

"RST Engineering (jw)" wrote:

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

Graham

OK, I'm going to try and put a stop to this senseless bull**** badminton
game. Graham, point me to a page where you were the chief engineer on a
product that is on the market for sale.

The most recent.
http://www.studiomaster.com/products/VMS.htm

Graham

OK, then, all I can say is that I pity your poor customer's technical
service department trying to cope with your nonstandard nomenclature.

Jim

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


"Eeyore" wrote in message
...


"RST Engineering (jw)" wrote:

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

Graham

OK, I'm going to try and put a stop to this senseless bull**** badminton
game. Graham, point me to a page where you were the chief engineer on a
product that is on the market for sale.

The most recent.
http://www.studiomaster.com/products/VMS.htm

Graham

"RST Engineering (jw)" wrote:

OK, then, all I can say is that I pity your poor customer's technical
service department trying to cope with your nonstandard nomenclature.

They understand it perfectly. US usage is deprecated here.

Graham

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.

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).

---
Attached...

JF

On Sat, 6 Dec 2008 10:00:40 -0800, "RST Engineering \(jw\)"
wrote:


We've developed one that works well for us. R1 is mounted on the cabinet or
chassis. R101 is on the first subassembly (generally a pcb), R201 on the
second subassembly, and so on. I've been asked what happens when you get
past the 9th subassembly and I reply that we are building small aircraft
electronic devices, not locomotives.

---
Why do you top post?

JF

On Sat, 6 Dec 2008 09:58:33 -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


Respectfully disagree, John. I grew up in the era of the #47 pilot lamp
being ubiquitous in radio dial lighting in everything I worked on that
needed backlighting or pilot lights. (I) was the standard; I never once saw
DS.

---
DS was used in military equipment and stuff that was documented to ANSI
standards.



JF

On Sat, 06 Dec 2008 18:09:49 +0000, 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.
---

Connectors can be CN, CON or CONN.

---
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.

JF

---
Why do you top post?

Because in this one, where I am asked a direct question, it makes more sense
to answer immediately after the question. In some where the body of the
message is quite long, it makes more sense to comment directly to that
paragraph inside the body of the message. In some, where it is a general
comment made in oblique reference to something that is said, it makes more
sense to top post as it would look in an original message.

Jim

On Sat, 06 Dec 2008 18:11:31 +0000, Eeyore
wrote:



Tom Del Rosso wrote:

"Eeyore" wrote
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.

Why use another letter when you 2 that describe the part properly ?

---
Why add another designation when there's absolutely no ambiguity
surrounding the original?

JF

On Sat, 06 Dec 2008 18:12:50 +0000, Eeyore
wrote:



Jim Thompson wrote:

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 ?

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

Not on a circuit board it isn't.

---
Geez, Graham, it sure doesn't take long for that veneer of adequacy to
wear off, does it?

JF

On Sat, 06 Dec 2008 18:25:10 +0000, Eeyore
wrote:



John Fields wrote:

Eeyore wrote:
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.

---
Where?

In one of the sci.electronics groups.

---
This one, a few minutes ago, huh?

JF

Eeyore wrote:

"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.


Actually, I didn't. The British designs were something they
couldn't build, so why brag about being so incompetent?

Radio, RADAR and electronics, in general was a new field, so lots of
designs were worthless mental exercises withiout the knowledge to round
off the rough edges and make the damn things work.?


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The crazy, and the insane.
The first sign of insanity is denying that you're crazy.

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.


Your replies are all particularly STUPID responses, and we expect no
more from you.


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

Graham


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Eeyore wrote:

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


Sensible people use TP to wipe their ass.


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The first sign of insanity is denying that you're crazy.

John Larkin wrote:

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.


Who in their right mind would expect to sell to NASA, NOAA, and the
US military or the aerospace industry, using crap designators like the
dumbass donkey does? Of course, his target market was burnt out
druggies, running crappy sound systems.


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.


I agree 100%, John. In fact, I still have a copy of the Microdyne
design reference manual around here somewhere, and it uses US & NATO
military designations. It was written in the early '70s, and was still
the design bible when L3-Com bought them out in 2000.


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The first sign of insanity is denying that you're crazy.

On Sat, 6 Dec 2008 10:00:40 -0800, "RST Engineering \(jw\)"
wrote:


We've developed one that works well for us. R1 is mounted on the cabinet or
chassis. R101 is on the first subassembly (generally a pcb), R201 on the
second subassembly, and so on. I've been asked what happens when you get
past the 9th subassembly and I reply that we are building small aircraft
electronic devices, not locomotives.


Tektronix used to use R1201 , R1301, etc on replicated circuits or
sections of circuits. Back when they allowed people to see their
schematics.

John

Eeyore wrote:

"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.


I had to throw you a bone, dumbass.



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The first sign of insanity is denying that you're crazy.

Eeyore wrote:

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


It could also be confused with (TR)ansformer, dumbass.


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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:

"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.


That are incapable of even producing 50% of the worlds weapons &
defense electronics let alone medicnes and other expensive research.



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Jim Thompson wrote:

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 ;-)


DD: Demented Donkey


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John Fields wrote:

On Sat, 06 Dec 2008 18:12:50 +0000, Eeyore
wrote:



Jim Thompson wrote:

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 ?

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

Not on a circuit board it isn't.

---
Geez, Graham, it sure doesn't take long for that veneer of adequacy to
wear off, does it?


So much for him being civilized, and well educated. The dumbass can't
even tell when you are joking with him.


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The crazy, and the insane.
The first sign of insanity is denying that you're crazy.

"Eeyore" wrote in message

Tom Del Rosso wrote:

U is 100% unambiguous too. It means IC.

Why use another letter when you 2 that describe the part properly ?

I first saw U on a schematic around 1980, because that's when I first saw
schematics of a commercial product. Before that, all I had seen were the
diagrams in Popular Electronics magazine, and they always used IC.

So honestly, it conveys a meaningful distinction for me. When I see U that
tells me it is (more likely to be) a professional design.


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On Sat, 06 Dec 2008 14:35:22 -0500, "Michael A. Terrell"
wrote:


Eeyore wrote:

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



What a hideous hack!

John

"John Larkin"
wrote in message ...
On Sat, 06 Dec 2008 14:35:22 -0500, "Michael A. Terrell"
wrote:

Eeyore wrote:

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

What a hideous hack!

John


Doesn't the term 'Hack' imply that? ;-)

Bill Garber

"RST Engineering (jw)" wrote in message
...

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


Respectfully disagree, John. I grew up in the era of the #47 pilot lamp
being ubiquitous in radio dial lighting in everything I worked on that
needed backlighting or pilot lights. (I) was the standard; I never once
saw DS.

Jim

Some of the Emerson schematics I see use DS to indicate a LED.

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.

---
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

"RST Engineering (jw)" wrote:

---
Why do you top post?

Because in this one, where I am asked a direct question, it makes more sense
to answer immediately after the question. In some where the body of the
message is quite long, it makes more sense to comment directly to that
paragraph inside the body of the message. In some, where it is a general
comment made in oblique reference to something that is said, it makes more
sense to top post as it would look in an original message.

At least you think about it, unlike some degenrate top posters who will post at
the top of 200 lines of text (mostly pointlessly repeated).

Graham

John Fields wrote:

Eeyore wrote:
Tom Del Rosso wrote:
"Eeyore" wrote
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.

Why use another letter when you have 2 that describe the part properly
?

---
Why add another designation when there's absolutely no ambiguity
surrounding the original?

Well if I posted a question in s.e.d asking " Do you know any Us that can
convert frequency to voltage ?" it would looks bloody silly wouldn't it ?

So stick with IC !

Graham