What's the best way to terminate very fine stranded wire

I'm using a 9 pin D-sub connector with attached cable. The conductors are stranded 30 guage (7/38). What's the best way to terminate these conductors?

- crimp (I don't have connectors sized that small, but I'm sure that I could crush larger ones enough to hold)

- solder (I've heard that this is bad, but there will be minimal flexing as the cable has strain relief)

- capture under a screw with washer

Thanks, Bob

Reply to
Bob Engelhardt
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Pick up a bag of Molex 016-02-0096 (Digikey WM2562-ND). They're pretty inexpensive and are sized for 24-30 AWG. Fit connector housings, e.g. for 10-position 50-57-9010 (WM2808-ND).

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Rich Webb     Norfolk, VA
Reply to
Rich Webb

IDC socket connector that plugs into a mating header.

Reply to
Andy

"Bob Engelhardt" schreef in bericht news: snipped-for-privacy@news7.newsguy.com...

Terminate to what? Another connector? A PCB?

Generally speaking, crimping is the best way... If only you have the right tooling and material.

Soldering to another connector is no problem. Finish with a piece of heat shrink tubing.

Soldering to a PCB is also easy but strain relief is more critical. A solder junction should never be loaded mechanically.

Capturing stranded wire under a screw, even with a washer, is not a good idea. There are however connection blocks that are prepared to handle stranded wire.'

IMHO yoo'll need strain relief anyway.

petrus bitbyter

Reply to
petrus bitbyter

I've always felt a certain security with soldering, but you have to strain relief it further back up the wire. Crimping is great but you need the right tools. Screw and washer is for thick single strand wire. At least you didn=92t mention insulation displacement. (I hate that!)

George H.

Reply to
George Herold

Yeah, another usenet'er asking for help without saying what the problem is.

What I'm doing is connecting a control box to a separate box with switches & lights. The D-sub connector is on the control box & I need to connect the cut wires on the other end to the switches & lights. Which have rather bulky screw connections. So I need to interface the

30 ga (7/38) wires. I can add a Jones strip, a piece of perf board, whatever.

The smallest crimp fitting I have is 22-16ga. How about if I "sister" a piece of stranded 22 ga beside my 30 ga & crimp the 2 together. Would that make a secure connection?

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I could do that with a piece of perf board.

OK, I can see there might be some strands that are not captured.

The cable has strain relief where it enters the switch box, but there will be a 6" or so run inside the box. How close does the strain relief need to be to the connection?

Thanks, Bob

Reply to
Bob Engelhardt

Thanks. What do you think of adding strands to get enough to fill a=20 crimp connector? Otherwise, it look like solder.

Bob

Reply to
Bob Engelhardt

Here's what I did: I took a small piece of perf board (1" x 2"), wove the wire through a couple of holes, & soldered it. The weaving provides very good strain relief - no amount of tugging affects the solder joint. It will be mounted on a standoff.

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Thanks to all the Reply'ers, Bob

Reply to
Bob Engelhardt

Bob E wrote

Bad how?

Reply to
Greegor

To terminated a thin wire you have to bash it several times with a hammer. Many things can be terminated that way.

Reply to
Shaun

That the solder can wick up the wire from the joint & stiffen it such that it's more likely to break from flexing.

Bob

Reply to
Bob Engelhardt

With no other strain relief, perhaps. Your perf board thing took care of that, sort of.

Even that creates a focused flex point doesn't it?

Reply to
Greegor

Right. Strain relief "upstream" of all solder would fix it. That's what I did.

Yes, where the wire exits the board there is focused strain. But there is no solder anywhere near that.

Bob

Reply to
Bob Engelhardt

Shop around for a crimp connector that's sized for the wire.

Don't tin this stuff - that makes it brittle.

Good Luck! Rich

Reply to
Rich Grise

Combining strands of different diameters does not look like a good idea. I've tried incidentally but sometimes the thinner wires could easily pulled out while the thick ones fitted thight. Doubling the strands by bending the stripped part of the wires by 180 degrees worked fine for me but might not be enough for you.

I've used "soldereyes" or "solderlips" to connect stranded wires to screw connections. There may be other names for it but they look like washers with a large hole for the screw and a protuberance with a small hole to solder the wire. Finish with a piece of heat shrink tubing.

Perfboard will do well. Pull the wire two times trough the board before soldering. That will give plenty of strain relief for 6" of wire as the mechanical stress pulls on the bends in the wire rather then on the solderjunction itself.

petrus bitbyter

Reply to
petrus bitbyter

ate

Sounds fine to me, (but I'm hardly an expert.) I also will strip a long piece of wire and then double it over on itself. This makes it thicker. If not enough double it twice.

George H.

Reply to
George Herold

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