Connecting to the real world

Hi,

Perhaps you could use a microcontroller to multiplex the signal(s) onto a serial link with fewer leads to connect. I suppose an optical coupling would be ideal if you want to make it waterproof.

Regards, Alan

Thanks, but we are already using a serial link. But we also need to provide other signals for power, and for customers that cannot use the serial link.

Not ribbon cables. If you want to use a standard ribbon cable style header on your board, then try Tyco AMP 102387 (MOD IV) series housings. These accept wires with crimp socket contacts. The other ends of the wires can then be crimped to any contact suitable for your waterproof connector.

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Greg Neff VP Engineering

Look at automotive connectors. They can get hefty, but they're quite water- and dirt-resistant.

Good Luck! Rich

Try Permatex blue RTV engine sealant from your local car parts store. This stuff will withstand almost anything. Use a wide bead area if user disassembly is a concern.

Hi,

I have a PCB with 0.1 inch dual row headers, inside a sealed metal box. I need to connect the Real World to it. We usually avoid using external connectors, but in this case we need to make the whole box "unpluggable" and do not want the end user going inside the box.

Does anybody know of any "waterproof" (IP67) connectors suitable for terminating ribbon cables (4-12 ways)?

Ideally I would like to use insulation displacement style terminations at the bulkhead connectors, but I can't seem to find any.

We have tried various circular connectors with "solder bucket" pins; they are very fiddly and time consuming to wire up. Also the ribbon cable wires tend to drop off since they are very thin! Then the others drop off while you are fixing the first one etc...

What do people use for this?

Thanks,

Use an ITT Cannon - TNM IP67 circular connector. The QM range of pcb-mount pins will fit the TNM. So have a small pcb at the rear of the connector, converting the round pin layout into a 0.1" IDC header. 1:1 IDC cable from there to the main pcb.

In the RS cat: 265-9705 chassis plug, and 349-8854 gold-plated pcb TNM contacts.

Thanks Tony!

Actually I had already considered something like that with the connectors we tried... glad idea not completely barmy.

I just got the new catalogue the other day. The contacts appear to be discontinued! Possibly I can get elsewhere though.

Thanks,

Getting the pins lined up exactly right before soldering is liable to be the bum-biter though.

I suspect it will need slightly oversize holes in the pcb, assemble the plug, plug it into a socket, *then* solder the pcb on.

Ahhh... Practice, Practice - you also need heat-shrink on all the wires .... ;)

The semi-mil circular connectors are the only ones that will last with dirt and moisture around - you *can* get types with crimp-pins but splitting ribbon-cable and crimping the ends is IMO at best a Hobby-Thing (in larger series, I would consider it Cowboy ;-).

One solution, i have seen, was to use a flexible mylar "pcb" with a layout matching the connector, solder the connector into that and connect the other end via some kind of header. But that costs..

Maybe your best option is simply to have someone specializing in wire harnesses produce a quality connector assembly for you. With a little flexibility in connecting the other end - i.e. you might need to loose the ribbon - it is probably not expensive either compared to endless D.I.Y efforts.

Yes, doing that too... of course that takes even more time, and makes it harder to inspect / fault find.

Agreed :). (Actually we are just supplying the PCB, it is my customer that is "packaging" it).

Yes. It looks like the easiest option is to accept losing the convenience of the ribbon cable (as suggested) and just use individual wires. You can get crimp housings that go onto the PCBs dual row 0.1 inch headers, instead of the IDC ribbon. The thicker wires that these will accept should solve most of the problems. Still surprised you can't get an IDC "military" style circular connector though.

"John Devereux" skrev i en meddelelse news: snipped-for-privacy@cordelia.devereux.me.uk...

Of Course - I have forgotten that; Those are very widely used - so the tools/people who can do them are available.

That's the Millitary for ya: "If it was good enuff for General McArthur then it's damn fine stuff, son" ;-) ....

And it takes many approvals from many V.I.P's to get different components authorized - maybe the manufacturers do not see the point in trying to push a new standard, after all: Soldering this stuff up is routinely billed at "cost + x%" in millitary contracts, so it is only a lead-time problem for everybody (except for the Tax-payer, but maybe he/she works at Raytheon anyway).