Re: NEED: TA7805S & TA7805F Bipolar Linear Integrated Circuits

"Barry & Nikki" <bearmore@xxxxxxxxxxxxxxxxxxx> wrote in
news:vtKdnXImPqtg0cbZnZ2dnUVZ_v6dnZ2d@xxxxxxxxxxxxxx:

Didn't anyone read?? I don't need thousands of these; just a couple.
Sure the part is common, I found it on every website that I went to
PRIOR to my post. Yes it is "cheap" but add in the shipping (or most
require min. orders) that is required by these companies and it makes
it not such a great deal. Newsgroups I thought were here for dealing
with others with similar interests. Obviously everyone just wants to
point out the obvious and share their infinite knowledge of a damn
little part. If they are so common like everyone is so conveniently
pointing out then why doesn't someone on this group have any (other
than the one poster that is obviously based in China trying to sell me
thousands of these) in a little parts bin. I came here hoping to trade
mainly (one thing newsgroups were initially intended for) not get a
blasting telling me how to use a search engine etc...
As to "package" type; YES I do need these specific types becasue
of
circuit board layout restraints. So just "Any old common one will
work" does not make the grade. You think I would waste my time asking
here if I had not already done my research and been down to my local
"parts shop"? Obviously most here must think so.



If you'd done so much researh you could tell us more than we've told you,
why didn't you tell us to spare us repeating work, or doing things that
weren't helpful?

Those parts are standard electrically, but I see they're not standard
containers for them.

The first is easy, at least. TA7805S truly IS a standard part, bar the
resin covering the tab. You haven't said a word about context, so whether
they are to be run on a heatsink or not is anybody's guess, but if so, use
a silicone or mica insulator and a nylon bush to insulate it, and if not,
get some kind of insulating tube fitted tightly round it, preferably
something like silicone impregnated fibreglass in case it needs to run hot.

The second is tougher. If you can establish what current it has to provide,
see if a TO92 package can do it. Negative rails are usually drawing less
that positive ones, that's probably why they aren't specifying a TO220
package for that as well. What's more, the TA7805F seems to have two forms,
one with wires, the other with little bent pins for surface mounting. If
you need the wired kind, then a TO220 package will do fine, if there's
room. You could always cut part of the tab off it...

Find some broken equipment like fax machine, printer, scanner, anything
that might have its own power supply. You'll probably find the mounting and
insulating tube you'll want, as that's standard practise in a lot of gear.
You might even find the parts you need, as they're used in PSU's made in
bulk manufacturing, but rarely sold in small amounts for field replacement.

As they're probably made for a specialised design, did you try to contact
the maker?

Last: try CPC (Combined Precision Components) of Preston Lancashire, UK.
They specialise in supplying this kind of semi-custom part to anyone who
asks and will pay for the shipping, anywhere in the world. They sell in any
quantity you want, if they have the parts.

And in case this post still leaves you wanting to bawl and curse at me,
remember that apart from that CPC tip, I knew NOTHING about these before. I
have done nothing that you couldn't have done for yourself. When you give
up 40 minutes to exclusive attend to one of MY problems, THEN you will have
the right to curse me. >:)
.

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