|
|
| Author |
Message |
rcurl
|
|
CONNECTORS
| 
Jan 4 20:27 UTC 1995 |
There is probably no harware item with more intricate diversity than
*connectors*. Yet, only the XLR has been discussed here (item 47).
This item if primarily for help with finding/using connectors, lets
hear some amusing or horrendous connector stories too.
|
| 50 responses total. |
rcurl
|
|
response 1 of 50:
|
Jan 4 20:38 UTC 1995 |
When I lived in England, I discovered that there were more than a dozen
ordinary household 2-conductor electrical "plugs": differing in
prong shape (flat or round), width/diameter, and spacing. In one home
I counted 14. Generally the bigger ones were for bigger currents
(and vica versa), but no one could explain the variety. I have the
same feeling of amazement and befuddlement over the variety of RF
connectors (UHF, BNC, F, N, SMA, MHV, SHV, C, HN, SC, SSMA, LC,
TNC, SMC, SMB, SSMB, D, and BANANA (did I miss any?)). Then, there
are computer connectors......but I'll let this item loose, before
I ask about one I'd never seen before.
|
tsty
|
|
response 2 of 50:
|
Jan 6 15:24 UTC 1995 |
RCA, 1/4", Ampex, alligator, DIN, Amphenol, Molex, barrier ...
|
rcurl
|
|
response 3 of 50:
|
Jan 6 16:51 UTC 1995 |
Are connectors a metaphor for human discursiveness? The variety of
connectors is mirrored in the variety of shampoos, cars, computers,
and practically everything else people use. Generating this variety
consumes an enormous overhead of repetition. On the other hand,
functional variety, and competition, are both valuable and lead to
innovation. But I think the balance has gone too far when so many
essentially identical but incompatible "thingies" are produced by
society.
|
tsty
|
|
response 4 of 50:
|
Jan 8 08:55 UTC 1995 |
ok, tyr connecting tri-ax with alligator clips ... or disk-drive
signals with phono plugs ....
|
tsty
|
|
response 5 of 50:
|
Jan 8 08:55 UTC 1995 |
<G!>
|
rcurl
|
|
response 6 of 50:
|
Jan 9 00:19 UTC 1995 |
Those would, at least, be adventurous.
Here is my particular connector question: my Garmin-40 GPS has a
computer interface and external power built-in connector, which is
a 0.53 in diam by 0.31 in deep cavity, with 4 D-Sub pins on a ca. 0.31
in diam circle (equally spaced), a key at 45 degrees, and a ca. 0.07 in
diam central plastic pin. I know the pinout (gnd, +6v power, RS-232
send and receive). What connector is this? (The Garmin power and data
plug for this is, of course, somewhat expensive.)
|
gregc
|
|
response 7 of 50:
|
Jan 9 12:29 UTC 1995 |
Hmm, kind of sounds like a varient of a DIN style connector from your
description. It's about the size of an IBM keyboard connector?
I'd have to get a look at it for sure. Is the plug smooth or are there
threads?
|
rcurl
|
|
response 8 of 50:
|
Jan 9 15:13 UTC 1995 |
I'd like to find or make the plug. The socket (with the pins) is
smooth. I have D-sub socket (female) "pins" (for DB connectors), so
I can easily connect wires to the four GPS pins, but I'd like to house
that setup.
|
tsty
|
|
response 9 of 50:
|
Jan 9 15:27 UTC 1995 |
Hmmmm, well ... from my handy Woodchuck's Handbook, it sounds
very similar to an AMP, Series 1, CPC (circular plastic
connector) with size 16 contacts, 4-position with built-in
pin and socket protection, positive ident locking, and
key-polarized.
But, hey, what do I know ...... <g>.
very popular for the aircaraft/computer/instrumentation
industries.
Does yours have thread-assisted coupling or bayonet coupling?
And which wire size would it use, 18-16 AWG, or 22-28?
The contacts are different for the different wire size.
|
rcurl
|
|
response 10 of 50:
|
Jan 9 15:48 UTC 1995 |
Hey! Do you have one? No coupling at all - it's just a cylindrical
cavity (i.e. hole) in the plastic body of the GPS. The pins are the
same size as in ordinary DB computer cable connectors. The D-Sub
female pins (sockets) are made to be crimped with a tool, and would
take 18 AWG wire, but all currents are very low (ca. 120 ma power).
|
tsty
|
|
response 11 of 50:
|
Jan 10 14:56 UTC 1995 |
Hmmm, if that's just a friction-fit connector, I "found" the
wrong one.
It could be a customized variant, as gregc noted, of a DIN plug.
Can you identify any mfgr markings on it?
|
rcurl
|
|
response 12 of 50:
|
Jan 10 15:34 UTC 1995 |
Its integral with the body of the GPS - not a separate fitting. What's
the prospect of building one? Cast the body out of (something?) with
the sockets inserted? I'd be a little concerned about casting it right
in the GPS, as I don't know what plastic it is and what might dissolve
it, but I could test castable polymers.
|
gregc
|
|
response 13 of 50:
|
Jan 12 00:34 UTC 1995 |
I think you'd be much better off trying to *buy* a connector, than
build your own. 2 suggestions: Have you tried contacting the manufacturer?
It seems to me that they just *might* have some idea about where to
get a connector. Or, take the unit to RS electronics on schoolcraft rd
in Livonia. If they don't have one in stock, they can probably order it.
They have a *huge* warehouse. They are a major electronics distributor,
of about the same size as companies like Newark and Hamilton-Avnet.
|
rcurl
|
|
response 14 of 50:
|
Jan 12 06:02 UTC 1995 |
Yes, there are power and computer interface accessories from Garmin.
But, where is the adventure in that (and the money savings). I *know*
you make things sometimes, instead of buying them, Greg. (In addition,
no accessory information or dealers names came with the unit, and my
call to the company got an answering machine, and the information I
asked for hasn't come....so I'm day dreaming about rigging my own.)
(And I showed the unit around at the ARROW meeting, and had offers
of machining a plug for it - see? others are just as taken with these
little "trivial" challenges.)
|
gregc
|
|
response 15 of 50:
|
Jan 14 13:49 UTC 1995 |
Nothing wrong with that. You just hadn't made your intentions clear.
If your main goal is just to see if you can make your own connector,
well then, have at it. OTOH, if your main goal is to acquire the information
available on that plug in a timely and reliable manner, then you are
better off buying professionally made parts.
|
tsty
|
|
response 16 of 50:
|
Jan 14 17:37 UTC 1995 |
Another option would be to substitute a more commmon jack/plug for
the one that is in there. Being integral has its limits.
|
rcurl
|
|
response 17 of 50:
|
Jan 14 19:36 UTC 1995 |
TS, the whole unit is "integral"! It is hermetically sealed with a dry
nitrogen interior atmosphere (because the unit is meant for use on deck
aboard boats, and *everything* gets soaked on boats). This inquiry has
been useful to me in other ways. It led to the comment that the connection
might be TTL and would need an interface to EIA-232. I'll put a scope on
it to see, but that might be enough to disabuse me of do-it-myself ;-!
|
tsty
|
|
response 18 of 50:
|
Jan 15 14:58 UTC 1995 |
well, don't let that hermit out -
|
n8nxf
|
|
response 19 of 50:
|
Jan 16 13:05 UTC 1995 |
TTL level is easy to convert to RS-232. A single 16 pin chip, 4- 10uf
16v capacitors and some wire. Using the 4 caps, it even has a charge
pump supply to generate the required RS-232 voltages. One could build
the whole thing on a square inch of PC board space. (I'm speaking of a
MAX-232 and like devices.)
|
rcurl
|
|
response 20 of 50:
|
Jan 16 17:15 UTC 1995 |
I've heard of such. (I've heard of so much, but still know so little -
funny how that works.) I'll be back after I check levels, and see what
the Garmin accessory info is: both should add information 8-}.
|
n8nxf
|
|
response 21 of 50:
|
Jan 17 13:16 UTC 1995 |
One could even take a standard serial card and pull out the 1488 and
1489 (Or equiv.) line drivers. They would be replaced with jumpers.
Then one wouldn't need to convert the TTL level signals from the GPS.
|
rcurl
|
|
response 22 of 50:
|
Jan 17 22:39 UTC 1995 |
I scoped the in/out pins, to ground, and they are at ground potential
with no signal, with the Garmin on, *but not acquiring data* (i.e.,
indoors). Does that give any hint as to what kind of interface it is?
(I misremembered an earlier measurement which I thought showed a
potential.) I'm going to have to get the tech data.
|
mdw
|
|
response 23 of 50:
|
Jan 18 03:07 UTC 1995 |
It might also be current loop. Why +6v ? You ought to be able to ask
the Garmin people what the interface is.
|
rcurl
|
|
response 24 of 50:
|
Jan 18 06:22 UTC 1995 |
The specs say +5 to +8 V for external power, but 4xAA are used for mobile.
I'll keep pursuing Garmin, but they haven't responded to my request
(taken on vice mail).
Now would be a good point for someone else with a CONNECTOR problem
or question to jump in. Next time I have more info, I'll post it in
the GPS item.
|