Help me with simple connector choice?

Is this connector to be used internal of a chassis, or connecting external units ?

For internal, I like these.

So, you want to mount the connector itself on a panel and have pigtails run off to the PCB? I.e., the connector does NOT mount directly to the PCB...

Meaning "latching" so, when mated, the two bodies don't (easily) separate. How difficult do you want it to be for a user to

Presumably, this implies the "cable" fastens to the connector IDC style? I assume you want this to be true of the *mating* connector, as well?

Boo! Hisssssss!

These are an abomination (as well as that same style used for ethernet shells). They too easily are damaged rendering them unreliable (at best!).

What role does the connector serve in your design? Is it mated/demated frequently? Is it easily accessible? How likely is the user to plug The Wrong Thing into your connector (or, to plug the *mate* into someplace where it shouldn't be -- e.g., using the RJ11 example, would they "accidentally" plug a telephone into your device, etc.?) What are the consequences of a connector failure or intermittent?

There are a gazillion choices, aren't there!

I'm fond of the 2mm PH-series from JST. They seem to meet all of your requirements, although you'll need a crimper that can handle the small contacts. Digikey et al. carry the PCB headers and cable-end housings. Also, they're pretty inexpensive.

If you need a crimp tool, the Aven 10140 (also Digikey and the rest) works pretty well for prototyping and small runs and isn't $$$$.

Our Hardware Guy loves the Mini-Fit Jr but they can be (relatively) large. Also, one MUST pay attention to the contact numbering scheme, which isn't in the "standard" DIL sequence.

No, I want a PCB to cable/wire to PCB system. PCB-mounted pins and cable/wire hanging headers

The end user will never deal with these, they will be inside a box. They will never be disconnected once connected, barring some kind of failure. In fact, if there were a way to quickly strip and solder or crimp 4 wires onto a PCB in the field, there would be no need for mating connectors.

Mated/demated very infrequently (one-time connect would be the norm). In fact, if a quick and cheap solution could be found that is permanent (no disconnect once connected), the economics would justify throwing away the whole module upon failure.

If the installer plugs the wrong cable into a particular connector, nothing bad will happen in terms of danger or permanent damage. These connectors will not be seen or accessible in normal use, unlike e.g. the connectors on a PC.

Ah, OK. The equivalent of a ribbon cable interconnecting two PCB assemblies (?)

How close together are the boards? Are the "connection points" on the edges of the boards (assuming the boards are already laid out)? E.g., could you literally position the two boards adjacent to each other and install "0 ohm shunts" to bridge the gap between them? Or, are the connectors "wherever was convenient" and now you need to bridge the three dimensional space between them?

This last bit is what prompted my "0 ohm shunt" comment. Note that you can purchase "flex cable" with tinned solid core ends of various (short) lengths (think of it as stiff ribbon cable) and "top solder" the ends into pads on each PCB.

A 2" example can be seen here:

Note carefully the ends of the cable. They appear as if someone had *started* to strip them -- but left the insulation stuck on the conductors just before finishing. This keeps the conductors in the proper spacing until you need to actually solder them onto the board -- at which time, you would remove that "loose insulation".

Note, also, that they are available in various pitches. I opted for 0.1" as that is easy for even us old fartes to work with! :>

This has the advantage that the only "tool" needed is a soldering iron. *And*, it is serviceable -- you can unsolder the connections if need be. Likewise, for *quick* troubleshooting, you can *snip* the connections, run your test, determine if a board needs to be replaced and, eventually, install a new "jumper".

See above. This would give you the option of saving one (or both) boards if you can troubleshoot in the field.

HTH,

--don

The microfit is the next one down from the minifit family. Quite a bit smaller.

Just the type I wanted to suggest. They ar not locking but they hold pretty good. We use them for an application on moving and vibrating parts and have not had any problems with them.

It's probably a confusion on my part between "locking" and "latching" so anyone please jump in with an EIA definition or the like.

My rather vague differentiation is that a locking type is passive, it "locks together," whereas a latching type requires an active effort to disengage the latch.

The PH connectors in this example do lock, with the rectangular cutouts in the header shroud mating with a pair of bumps on the connector body, so that it snap-locks into place but releases with a straight pull.

The Mini-Fit connectors, on the other hand, have a latching arm on the connector body that snaps over a detent on the header, requiring a separate action to open the latch before the connector can be removed.

So pedantic and I haven't had the morning caffeine yet... ::sigh::

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Do you feel you need the latches for vibration/shock resistance? If you are unconcerned about appearance and disconnecting this in the future is both rare and done by service personnel ,consider a coupla of dabs of RTV or silicone sealer on the ends of 'normal' connectors after mating/testing.

Well, I'm not the one who was looking for connectors but I have worked on some projects that have passed 901D Grade A shock (lightweight, rigid mount, big f'ing hammer). That equipment did use a lot of the Mini-Fit Jr latching connectors. I suspect that the PH connectors would do fine as is, given their configuration and relatively low mass.

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oops - sorry.