On Jan 15, 22:54, Tony Duell wrote:
> > >Read that as 2SB1243 -- which is not in 'Towers International
Transistor
> > >Selector'. Can you check that number, please. In fact, please post all
> > >markings on the original transistors.
> >
> > I thought I did, unless there are more markings on the side against the
PC
> > board? I'll look again.
>
> Peter has already posted some info on this transistor. My 'Towers',
> normally a good reference for obscure transistors, has let me down... OK,
> it's not a particularly recent edition...
Towers is excellent, and I'd not be without my well-thumbed copy. I
suppose I should buy a newer one some day. However, it seems like every
time someone in Japan or other some other parts of the Far east designs a
circuit, they design or specify a new transistor for it -- a transistor
that is almost identical to some existing device, but has with some minor,
often trivial, tweak. I suppose it may save some corporation a fraction of
a yen on each of hundreds of thousands of units. Or perhaps the way it
works is that a designer says "I need a transistor with the following
parameters..." and someone makes a batch to order rather than using an
existing design (for which they have no stock, because of just-in-time
stocking) and the made-to-order gets a unique number, more like a batch
number than a type number.
That's why I bought the Japanese manuals (there's one for FETs and one for
diodes as well as the transistor one), and more particularly, why I posted
the main operating parameters. There are probably dozens of relatively
common types that could be used as substitutes for a 2SB1243. If you need
one, it's just a question of looking in your favourite sales catalogue and
going down the list until you see something close enough.
--
Pete Peter Turnbull
Network Manager
University of York
Received on Tue Jan 15 2002 - 18:08:12 GMT