Re: high curent PCB connector

On Sun, 16 Feb 2025 19:32:56 +0200, Tauno Voipio
<tauno.voipio@notused.fi.invalid> wrote:

On 16.2.2025 7.11, Bill Sloman wrote:

On 16/02/2025 3:17 am, john larkin wrote:

On Sat, 15 Feb 2025 14:13:20 +0000, piglet <erichpwagner@hotmail.com>
wrote:
>

On 15/02/2025 12:20 am, Phil Hobbs wrote:

piglet <erichpwagner@hotmail.com> wrote:

john larkin <JL@gct.com> wrote:

Does anyone have a favorite high-current PCB connector?
>
I'd like to get 20 wires into a pluggable connector, to go on a
module
like this:
>
https://highlandtechnology.com/Product/P948
>
We need at least 7 amps per contact.
>
That litle green Phoenix connector is cool. Wires screw into it
without tooling, and it's easy to mate and unmate. But it's only 5
pins.
>
I was planning to use four of them, with two on a baby board, but
that
idea wasn't popular.
>
>

>
Phoenix  do make 20 pin version (as two rows of ten) with 10 amp
per pin on
200 mil pitch.
>

>
Do they actually make them m, as in somebody has them for sale, or
are they
just listed in a catalogue?
>
Connector catalogs are full of things that they would love to make
for you
if you want to order 100,000 pieces and can wait six months.
>
Cheers
>
Phil Hobbs
>

>
But JL's customers are aerospace so will be used to exotic, hard to find
connectors - would they respect him for using an easily buyable
connector :)
>
piglet

>
The nice thing about the Phoenix connectors is that you don't need a
soldring iron or pins and crimp tools to terminate wires, just a small
screwdriver.

 
That's not nice. It's just cheap. At Cambridge Instruments the argument
for going over to crimp connectors was that you found a lot less duff
connections when you were putting product through final test.
 
The parts and tools were more expensive, but fault-finding and fault
correction were expensive enough to tip the balance.
 
<snip>
 

>
Crimps can also be dud, and they can be difficult to find.
>
Decades ago, we had a Data Products line printer which occasionally
went beserk with paper feed, throwing half a box of chain forms at
speed through the printer. The paper feed was a DC servo built by
the book, with acceleration and deceleration controls done with suitable
integrators. After a long hunt, it was seen that the occasional insanity
came from a missing tachogenerator signal. The culprit was one of the
tacho signal wires crimped partially on top of the insulation.

I had one of those problems in the 1970s when I lived in Baltimore,
but it was the pickup wires from the electromagnetic phono cartridge
on a Dual turntable that caused trouble.  Took me a year to figure
out. 

The phono pickup wires were very small and flexible, and they were
attached to the cartridge by a pair of spring clips crimped to the
wires.  What they meant by crimped was that they stripped the soft PVC
insulation off for 1/8", folded the wire strands back over the
insulation, and crimped to that.  Almost worked. 

But after a few years in the industrial atmosphere of Baltimore (we
still had a real steel mill!), a little bit of corrosion formed, and
the wire to ferrule contact  became unreliable, and one channel or the
other would go silent, probably due to mechanical motion as one played
a record.

How does one fix this?  Replacement parts will all have the same
problem, and it's too small and delicate to do much, and soldering
would yield fatigue breaks.

Welding is the answer!  Took the cartridge off so all that's left on
the turntable is wire and mechanism, and no fragile electronics.
Connected each wire from clip to phono connector in series with a
100-watt 120-volt incandescent bulb and connected this to the 120-volt
power line.   The 120-volt 10-amp startup surge punched through the
corrosion and welded wire to crimp-terminal barrel.  The thin wire had
no problem carrying the 1-amp steady-state current thereafter.  Did it
a few times per wire, just to be sure.  Problem solved, never to
return.

Joe Gwinn