Two pin header assembly?

[Al (astral highway)]

Hi folks,

I bought some 2 pin headers online and as I only have a few, I don't want to write any off by experimenting with the assembly.

It looks quite intuitive but I'd rather get it right first time.

The shell of the header, male and female, is self-explanatory: however, the pins come on a strip, joined together. Clearly that has to be cut but I'm not sure about how the thing all gets put together.

Any pointers, much appreciated!

Thank you

[Refugee]

The strip makes them so that they can be put into an industrial crimper.
The carrier strip will short them all together.
You snap them off the strip like parts of an Airfix model and solder the wires to them.
Once they are clicked into the shells they are fiddly to get out again.

[emeritus]

The RS ones I used in the 1970's had a removal tool consisting of a very thin-walled tube (with a handle) that you had to push into the bore to depress the finger that held the pin in place. For some types (such as the current smaller size of Bulgin Buccaneer waterproof multipin connectors), once a pin is assembled to its shell, it is not practical to remove it.

[Radio Wrangler]

? There are many sorts of headers. Without knowing which type any advice could be misleading.

David

[Ed_Dinning]

Hi Al, a pic with some of the pins and headers may help, I have a good selection of different types here, as well as some of the special extractors.

Ed

[Al (astral highway)]

Thank you folks.

David and Ed, good point! I can upload some photos on Monday.

Most crimps need "crimping" before they will fit in the housing. Without a proper tool (read expensive tool, in the £100 bracket) simply fold the wings in and then solder the joint. Mind you for the very common crimps cheapo plier type ones are available on eBay etc. with some care they are adequate for home use.

[Al (astral highway)]

Most crimps need "crimping" before they will fit in the housing. Without a proper tool (read expensive tool, in the £100 bracket) simply fold the wings in and then solder the joint.

Woah! That is one expensive tool!

Thank you for the tip.

Here are the headers:

JST (Japan Solderless Terminals) by the look of them, or Molex.

An example of a JST tool http://uk.farnell.com/jst-japan-sold...20crimp%20tool a snip at £395, £13 discount if you buy two. We have one for their VH terminals at work, very nice tool (bloomin' well should be).

[Al (astral highway)]

Originally Posted by merlinmaxwell

a snip at £395, £13 discount if you buy two.

That price is just astonishing! After your tip, I managed to curl up the crimpable bits and pressured them into the case, using long-nosed pliers.

Thanks!

[McMurdo]

the ones on the strip are designed to be fed into an automatic machine that fires out ready-made wiring looms like spaghetti. The holes in the tin strip are sprocket holes a bit like auto insertion bandoliers.

I used to repair the ones at Creda, though back in the day they were controlled by a DEC Microvax!

https://www.youtube.com/watch?v=KzqoiMOU3jE

PS it's fiddly to trim the bandolier bits off. If the resulting terminal has a fraction too much left, they will jam in the housing and cause an intermittent mating arrangement. You can buy ready-cut (loose) JST terminals from Farnell/RS which are easier. I prefer to solder them with the tiniest bit of solder.

[Al (astral highway)]

Originally Posted by McMurdo

PS it's fiddly to trim the bandolier bits off. If the resulting terminal has a fraction too much left, they will jam in the housing and cause an intermittent mating arrangement...I prefer to solder them with the tiniest bit of solder.

Yes, it was a bit fiddly, but I used a pair of very sharp cutters and got a nice, clean cut. There is a bit of waste metal at the end of the crimpable bit, too.

In the end, I slightly curled the crimp in with pliers and then, just as you suggest, put a tiny bead of solder on the inside.

It worked out very well. It meant I could put a 50R dummy load mounted on a header to check the waveform of an (RF) complementary pair output stage. Now I've verified that this is working, I can remove the dummy load and put another header in to couple to the final stage. It's exactly what I needed, so I'm happy!