[TriEmbed] Favourite electrical connectors?

[Pete Soper]

Right about now you're saying to yourself "these RJ11 jacks are insanely 
large!" But it's a daisy-chain bus and your controller PCB is not likely 
to have more than one or a very small number of bus interfaces, so 
you're probably just dealing with one connector site (for the RJ11 jack 
I mentioned you need 16x17mm). Yes, that's maybe an extra dollar or 
dollar and a half on a set of three OSH Park boards vs using a DF13.

The issue, in my opinion, is getting practical, inexpensive, *impedance 
controlled* cable physically attached to the connector. It seems 
problematic to adapt CAT3/5/6 to a DF13 so you avoid work-hardening and 
breaking wires while getting the thing on and off, arranging the cable 
run, etc. The JST PH series of connectors (the ones you see all the time 
for lithium battery connections) might be an alternative (and I have 
pile of these and a factory tool to play with if you want to explore 
that). But in terms of physical connection the DF13 or JST are going to 
want some major help because only two to four wires can attach and these 
are very wimpy, solid copper wires. With an RJ11 you at least get six of 
(typically) eight connected. Unfortunately an experiment with heat 
shrink just now makes it clear there is no way to use this to physically 
secure the UTP to the end of the RJ11 plug: the entire plug goes into 
the jack with nothing left for an overlap of heat shrink.
-Pete

On 09/25/2015 10:18 AM, Charles West via TriEmbed wrote:
> Hello,
>
> I'm working on a board for the CanInstall autoregistration project and 
> I'm not really sure what connectors to use for it.  I'm currently 
> leaning toward either DF13-4 connectors or simple 4 pin headers.  If I 
> may ask, are there any other connectors that you would recommend or 
> have used in your projects?
>
> Pros/cons:
> DF13:
> The upside is that they are very small, connect very securely and SMD 
> female connectors are $.41 per.  The downside is that they are 
> extremely hard to get out (don't pull on cable, very gently pry with 
> finger nail on one side, then the other) and cables for them are 
> extremely hard to find/expensive ($1.5 per in lots of 20 is the 
> cheapest I've found).
>
> Vertical Headers:
> The plus is I can get break apart SMD headers at roughly $.05 each 
> including shipping at lots of $5 
> (http://www.ebay.com/itm/10pcs-2-54MM-1-40Pin-SMD-SMT-1-40Pin-Male-Single-Row-Pin-Header-/261879748701?hash=item3cf93fd85d), 
> cables at $.22 per in lots of $5 
> (http://www.ebay.com/itm/20pcs-2-54mm-to-2-54mm-Dupont-Wire-Cable-Connectors-4P-to-4P-Pin-Header-20cm-YG-/111487505711?hash=item19f52c552f) 
> and they are pretty standard for hobbyist projects (and extremely 
> similar to servo connections).  The downsides are that they have no 
> polarity control, are much more likely to slide out and take up a lot 
> more board real estate (translating to either bigger boards or less 
> connectors).
>
> Thanks,
> Charlie
>
>
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