David Nebenzahl wrote:

On 6/19/2010 1:19 PM Adrian Tuddenham spake thus:

David Nebenzahl wrote:

(And I don't much like their transistor symbols either)

For junction transistors they are incorrect, I agree, but I have become
used to them. I find it takes me a while to get my mind around the
correct symbols because they are so rarely used nowadays

Just for fun, I've replaced the point-contact symbols in that drawing
with the correct junction ones:

http://www.poppyrecords.co.uk/compto...Amplifier2.gif

The wrong symbols have become so well-estabilshed nowadays that I doubt
if most people even noticed they were wrong.

Now that's just plain *weird*.

I thought you would find them interesting.

Since when are the *conventional* symbols for (junction) transistors
considered to be for the old, obsolete point-contact ones?

When junction transistors were first introduced there was a need for a
new symbol to distinguish them from the point-contact type which the
'conventional' symbol represented. Several eminent journals and text
books changed over to the new 'junction' symbol, but, by then, the
point-contact symbol was so well established that the change never
caught on.

Every single
schematic that uses transistors--modern silicon ones, not ancient
point-contact germanium ones--uses the conventional symbols, like the
ones in the first drawing you posted.

You will find the 'junction' symbols in some Acoustical Quad circuit
diagrams, Peter Walker was a stickler for getting things right. They
also appeared in Wireless World for a while and are used in "The
Foundations of Wireless" by M.G. Scroggie (8th Edition) specifically to
distinguish the two different types of transistor.


I've *never* seen symbols like the ones in your "new, improved" drawing.
Those are just plain idiosyncratic, non-standard and weird. They look
kind of like diodes with an elongated anode.

They certainly look strange when you have been used to the
point-contact symbol, but you must admit they give a clear
representation of a junction transistor.


I'll stick with the tried and true standard symbols, thank you very much.

At least you will be able to recognise the other types if you ever
encounter them again.

--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk