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Discussion: Schematic designators: T vs Q (also U vs IC)

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TimFox:
My guess is "U" for "unit", but I never saw an origin for "Q".  "CR" for diode lasted a long time.  Perhaps "Q" comes from your DIN definition of its function?
"T" may be clear for transistor, but what, then, should we call a transformer?

RedLion:

--- Quote from: TimFox on July 14, 2021, 10:56:19 pm ---Perhaps "Q" comes from your DIN definition of its function?

--- End quote ---
No, I don't think so, that norm is quite recent.

--- Quote from: TimFox on July 14, 2021, 10:56:19 pm ---"T" may be clear for transistor, but what, then, should we call a transformer?

--- End quote ---
We use TR for transformer. Not better on the confusion bit, but well, whadyagonnado?
I've seen TF somewhere as well, not sure how I feel about that.

CatalinaWOW:
The use of U for integrated circuits comes from the ASME/IEEE standard where U is used for an "inseparable unit".  Logical but not the easiest thing to remember.

It doesn't seem that component designators have ever been important enough for force international standardization.  When the designator is next to the symbol (which is slightly more standardized worldwide) it is obvious enough, and in a stand alone parts list the part number identifies the part well enough that knowing its category isn't too important.  The only time I have really found much use for the designator is in sorting parts lists, and for that purpose consistency within the list is all that is necessary.  It really would be awkward using multiple designators in a single schematic.

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