power resistor solder post (in search of)

Hey-

I'm looking for some of these posts that you find cement power
resistors mounted to on PCBs.

They're little hollow posts that are inserted through the bottom of
the PCB that allow the leads of the power resistor to feed through and
solder to the bottom. I assume they're designed to sink a little heat
and allow the resistor to be mounted sturdily above the board level.

Anyway, I (always) have trouble heating them up and removing all the
solder to install new resistors.

Anyone know what these are called, so I can poke around on mouser or
elsewhere for replacements?

Thanks for any assistance-

Kerry

 

If they're the things I'm visualizing from your description, one name
for them is "hollow turret terminals."

 

Could you post a pic to some hosting site, or at least some dimensions, as I
don't recognise the description

 

I've seen these on manufactured boards many times, but I can't recall seeing
them sold anywhere. Smitty's name for them sounds right. You can also get
ceramic tubes for the same purpose, and I think the word 'standoff' comes
into them somewhere. Another method of standing power resistors off the
board in a mechanically robust way, is to use ceramic fishspines. You can
put as many as you like of those on each leg, to space it off as far as you
like. Once the resistor is pulled into the board, and soldered, they are
very rigid.

Arfa

 

But you don't want rigid, in the sense of clamped down to board fixing, or
board flexure + lead heating will lead to strain on the solder points, then
failure of joints

 

The metal tubes that he is referring to are quite common in TV sets and the
like, and I can assure you that they hold the resistors very firmly, and
inflexibly, to the board. Failure of the joints on them is not something
that I would have said was 'common' ...

Arfa

 

As I recall, they are called stand-offs or turret lugs. The component
lead usually seems to have a bit of movement in the tube, tho only
soldered at the board end of the tube. They are used a lot in Peavey
amplifiers and rarely seem to fail.

see here http://www.turretlugs.co.uk/

Ron(UK)

 

You need a stainless steel dental pick. Your dentist will probably give
you one that is getting dull. Or you can usually find them at flea
markets or dollar stores.

You heat up the post (in this case) and ram the pick down into the hot
solder. The pick pushes the molten solder out, and since the pick is
stainless, the solder doesn't stick to it.

With a little care, you can also use the pick to clear plated-thru holes
on a PCB.

Bill

 

They are called Turret Terminals. Several companies make them, but you can poke
around Mouser's current catalog on page 1541. Keystone makes them, even sells a
cheap staking kit for installing them to a board.

--
Dave M
MasonDG44 at comcast dot net (Just substitute the appropriate characters in the
address)

"In theory, there isn't any difference between theory and practice. In
practice, there is." - Yogi Berra

 

Thanks for the pointers-

I guess they're turret terminals. The ones I see on Mouser and on
the Keystone site are not as tall as these, but one is close.

I tried to grab some quick (rough) dimensions-

Inner Diameter- 1.2mm
Outer Diameter- 2.2mm
Base Diameter- 3.2mm

height (above board) 9.5mm (.37 in)

The ones I've found are skinnier than mine too. They probably don't
need replacing- it's just that they got heated up good to remove the
solder and now the plating looks funky. As long as they serve their
purpose...

Here are some snapshots just for reference:

http://home.sc.rr.com/kstillin/turret/turret1.JPG
http://home.sc.rr.com/kstillin/turret/turret2.JPG
http://home.sc.rr.com/kstillin/turret/turret3.JPG

One of them shows a thermistor installed.


Thanks again-
Kerry

 

They are rolled brass turret lugs/tags/terminals

Ron(UK)

 

Now seeing a pic they are familiar but no names known to me.
I've always known turret tags as the crenelated/castellated (as found on
castle turrets) small tags pressed into paxolin circuit board of valve and
wire-ended component days and Gardner etc high quality transformers for lead
terminations. Looking down on the top they have a cross recess for taking
wires in 2/4 directions.

 

I've destroyed many a PCB by trying to replace terminals. They're
mechanically swaged into the board prior to soldering. They *can* be
successfully replaced; I've done that, too. But it's just as likely that
you'll tear up pads and traces. Your pics show a single sided board
which would make replacement a lot easier if you decide to do it.

 

I was recently repairing a 30 yearold amp and those pins look very much like
the electrical socket type connectors fitted bare, directly to pcbs to mate
with line plugs of the Molex / QM type connector range, in UK terms.
As far as the bellied/swaged ends to solder onto the board, very similar,
the active connector ends are more open than the sort for thin leaded Rs ,
but could be used for R standoff/pillars