At 02:33 PM 2/13/01 -0800, Dennis Saputelli wrote:
>I hope it doesn't give CR for a diode !

standard is D or CR. I prefer D because it takes up less room. Sometimes VR 
is also used for a diode used as a voltage regulator

>or IC for a U

right. U is "inseparable subassembly, integrated-circuit package, 
microcircuit, micromodule," though A is used for separable subassemblies. 
IC is completely nonstandard and unnecessarily long.

(longer names, especially for common parts, make problems on the schematic 
and on the component legend [Protel "overlay."])

>so what do you do with a 3 pin regulator that looks like a Q?
>I have taken to naming them Q or sometimes REG
>if you name them U the assembly people look all around for an IC type
>package

Any assembler who hasn't seen a 78L05 or the like called U-something has 
been asleep for the last twenty years or more. I'd say that one out of 
fifty schematics I receive deviates from that.

Components are named for their function and character, not for their 
package style. If I have an inductor that looks like a resistor, do I call 
it "R"? I think not.

>personally I like Z for a zener and TZ for a tranzorb, but I'm sure
>these are non standard and will cause disagreement
>this way you can look at a board and have a small idea what is going on

True. However, standards in general help that process and leaving them can 
hinder it. Z for zener is fairly harmless, though it is usually pretty 
obvious what is a reverse-bias diode and what is not.

By this argument, using Q for a regulator will *really* confuse the tech.

>the real fun comes in trying to get J $ P to be logical and consistent

It's much easier than one might think, though most engineers don't know the 
standard.

The primary distinguishing characteristic is that J is stationary and P is 
mobile. If both J and P are mobile, or are equivalent stationary, which 
usually means cables floating around to be connected together, then P is 
male and J is female.

That's the standard. I'd add that if male and female are not 
distinguishable, as with some connectors which have both pins (male) and 
sockets (female), then I would make the hot connector (powered when 
unconnected) J and the other P, if there is any difference, which is what 
one would do anyway with good connector design.

I.e., the wall socket is J and the lamp plug is P, because:
         (1) The wall socket is stationary.
         (2) The wall socket is female.
         (3) The wall socket is powered.

So an extension cord has a P on the end which goes into the wall, and a J 
on the other end, even though both ends are stationary. Except for the one 
I made in an emergency when I had a job to finish and the power company 
told me my block's power was going off for the day and I rented a generator 
but not a transfer switch. That cord had P on both ends. Now I worry about 
it sitting around, that someone might need an extension cord and plug it 
in, before noticing that the other end was a bit unusual.

[EMAIL PROTECTED]
Abdulrahman Lomax
P.O. Box 690
El Verano, CA 95433




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