gnupic: Adapters (slightly off-topic)
Subject:
Re: Adapters (slightly off-topic)
From:
Tim ODriscoll ####@####.####
Date:
10 Feb 2002 14:39:43 -0000
Message-Id: <Pine.LNX.4.33.0202101416110.1229-100000@cube.stokepogesway.net>
Hi everyone,
Thanks for the replies, and the links to datasheets :)
Perhaps I should've rephrased my question:
When I ordered the BC547B part, the RS catalogue said it had a TO92c case
style, so I looked up this case style and it told me about the Gate,
Source and Drain. Not having heard of these pins before, I wanted to know
which pins these related to in the circuit diagram.
Anyway, one of the links I got was an explanation of the Gate in FET's and
that implied that it was equivalent to the Base in normal transistors,
which is pin1 in a TO92c style case. Hence my confusion as that would
involve bending the legs horribly to get it to fit.
Also, the programmer didn't work with the FET this way round. Fortunately,
I found a component layout for the programmer I was trying to build and it
showed me that the Base/Gate was infact the middle pin. I plugged the FET
in this way round and it started working.
I still don't know why the RS catalogue led me to a TO92c style case
(perhaps it's out of date), but that would seem to be the source of my
confusion.
Yesterday I rigged up two leds to my 16f84a and I managed to make them
blink alternately with my first .asm program!
Not bad for someone who left at Grade 3 :)
Now for the 16x1 LCD display....
Cheers,
Tim
On Sat, 9 Feb 2002, Garst R. Reese wrote:
> Tim ODriscoll wrote:
> >
>
> > When I was at school, the pins were Base, Collector and Emitter, and you
> > could tell where to solder them in by the circuit diagram where the
> > arrow was the emitter, and the base was the one that looked like it
> > was controlling it (cue dodgy ascii-art):
> >
> > C
> > /
> > /
> > B --
> > \
> > \|
> > - E
> >
> > So, in the picture above, is the Base where the Gate should be, the
> > Emitter where the Drain should be, and the Collector where the Source
> > should be?
>
> You should have stayed beyond Grade 3 ;>)
> Things with Gate, Drain and Source are Field Effect Transistors (FET's).
> But the Philips Master Replacement Guide lists the 123AP as the
> replacement, and it
> _____
> is a TO92 NPN Transistor, with pins 1,2,3 = E,B,C, where the overbar is
> the flat side of the device looking at it from the bottom.
> Good luck,
> Garst
>
