Suggestions for quick disconnects for a control center?

[Birds]

Happy Tuesday! 

My layout has stalled at the wiring stage, and I could use some suggestions.

When I built my train table, I didn't build a shelf, or area, for a control center.  I planned on putting the control stuff on a table with wheels and rolling it under the train table when not in use.  I just planned on having the two tables tethered together by the wires. 

As I have been working with the wiring on a temporary basis, I have decided that I don't like the looks, or limitations, of the control center being permanently tethered to the table.  I would like to find a way to use quick disconnects on the wires between the train table and control table so that I can move / remove the control center if there is a need.

What I am envisioning is a series of quick disconnects on the control center side, and a matching series of quick disconnects on the table side.  Then a series of "patch" cables that would connect the two.  And all of this bundled together as neatly and compactly as possible.

I've been trying to think of what to use as the disconnects, but the connectors used need to be able to handle 15 amps.

Basic specs:

• conventional operation
• 12 blocks
• 11 switches
• 2 KW transformers

Any thoughts or ideas on connectors would be appreciated.

Thank you,

Chris 

[lionelsoni]

I like Molex connectors.  The larger, "Standard .093" type has up to 15 pins and is rated for 14 amperes per pin when used with 14 AWG wire.  Two of these should do the job for you.

[chuck]

 

If you use stranded wire and flex conduit/cable minder sheathing it should work fine and look good too. 

[lionelsoni]

I lace my cables, using ordinary cotton string.  Here's how:

http://www.dairiki.org/hammond/cable-lacing-howto/

 

[Birds]

Thank you for the suggestions!

The Molex connectors were something I was origianlly considering (as well as audio banana plugs and binding posts), but when I added everything up it came to needing something like 66 individual connections.  I would like to reduce the number of connectors to as few as possible.

I came across these plugs:

http://www.cinch.com/products/pdf/Jones_PDF_Catalog1148360345.pdf

They are rated for 10A at 250VAC RMS.  I would prefer a 15A rating for a bit of a fudge factor.  However I protect the layout's center rails with either 7 or 10 amp fuses, so the 10A should be okay (and the KW's are rated for 10 amps).

The Jones connectors have connector options for 2 - 33 wires.  That should allow this layout to have three sets of plugs:

• 13 pin plug for center rail and outside rail track wires (12 center rail connections and 1 outside rail connection)
• 33 pin plug for the 11 turnout controllers (or two 17 pin plugs)
• 12 pin plug for constant voltage for turnouts

So I am thinking that I can do this with only three or four sets of plugs.

Each set would have 2 female ends (one female end at the train table, and one female end at the control box).  Then there would be a "patch" cord with male plugs on each end to allow one end would plug into the table, and the other end to plug into the control box.

It would be a lot of soldering on the front end, but I think this would make a very easy disconnect system.

Chris 

[lionelsoni]

Are you sure you need three wires per turnout?  They usually need only two, with the return common with the outside rails of the track.  And you should need only one wire for the turnout accessory voltage.  That gets it down to 36 wires--much less than 58.

You might be able to get rid of a few more turnout wires if you have arrangements where the turnouts can be coordinated.  For example, there is little use in being able to throw the two turnouts of a crossover separately:  You're either crossing over with both switches diverging, or not.

I would put male connectors on the layout and female on the control center, with male and female on the two ends of the cable.  That way there are never any "hot" male pins exposed.

Consider fully populating the cable from the start.  That way, you don't need to redo it when you add circuits. 

The Molex connectors are also rated at 250 volts RMS.

[bfskinner]

lionelsoni said,

I lace my cables, using ordinary cotton string. 

Bob, I've really got to hand it to you this time.

I haven't seen cable lacing instructions in over 60 years. In fact, I'm not sure I've ever seen them. My dad taught me how to do that, especially the end treatments, with the ropes on our boats to keep from losing the factory lay-up. He probably learned it as Naval officer-in-training ("90-day wonder") at Quonset Rhode Island at the beginning of WWII.  I thought it was a long lost art.

Personally, I haven't used it in years, resorting instead to Whip-End Dip liquid vinyl for rope, and plastic cable ties for my train stuff. It sure doesn't have the tradition of your method.

If your post is a joke it's a good one; but if you actually do it, it's a tour-de-force of the first water! I'd love to see some pics.

[Birds]

Bob,

Thank you for double checking the wiring amounts.

I don't know what I was thinking when I said a 12 pin plug for turnout fixed voltage wires.  This is a good example of why it's nice to have other train folks to run things by.  The constant voltage will be done as one line from the control panel to the table, with a terminal strip at the table, and star/homerun wired from the terminal strip to each turnout.

I haven't worked with turnouts using two wires.  I'll have to try that out, and also take a second look at having crossover turnout control each other.  It looks like I can eliminate four wires doing that.

I understand what you are saying about never having hot male pins exposed.  I hadn't reasoned through that one (too much time with computer networks and patch panels).

Chris 

 

[lionelsoni]

Actually, I use tie-wraps under the layout.  But my transformers (but not the turnout controls) are on an old portable-television cart that I can roll around and tuck under the layout when I'm not using it.  That's where I laced.  I think it makes the neatest, most flexible umbilical in a situation like that.

I learned to lace cables at the Tech Model Railroad Club about 45 years ago.  We used a lot of telephone equipment and imitated telephone practices.

[bfskinner]

Bob, 

Outstanding!

Would still like to see some pics.

[Sturgeon-Phish]

That looks beautiful.  I'm getting motivated to do some re-wiring!  There is some additional accesories I want add and will need to run more wire through the loom and thia may be the ticket!  Still looking at connectors.

Like the original post, a multi-wire quick type plug is what I'm looking for also.  I was thinking about trailer plugs.  Four wire flats, and number the plugs to match up. 

Thanks 

Jim 

[Anonymous]

I tried using the ones available at Radio Hack and that was a waste of money.

The FasTrack switches use 4 wires.

[bfskinner]

Bob,

Let me make sure I've got this right. While Lionel was developing MagneTraction, you were at the Rad Lab developing the Cavity Magnetron and early String Theory? Wow! 

[lionelsoni]

No, just crawling around under the layout.  We almost never actually ran trains.  We just tinkered with the "system".  It looked like a telephone exchange under there.  (In fact, there were two actual telephone exchanges besides the train controls, first something like a number-one crossbar, then later a step-by-step PAX inherited from the EE department, with an early Keith lineswitch instead of Strowger linefinders:  http://mysite.verizon.net/pdwills/cedartel/aepabx.htm)

[bfskinner]

Bob,

Sounds like great fun. Is that you on the Main Page designated as the "Wire Chief in training?"

I think that was about the time I stopped wasting my time in Berlin trying to make sense out of Heisenberg, but I can't be certain.

[lionelsoni]

No.  Just a handy web site with a picture I needed.  If you go to

http://tmrc.mit.edu/

and search on "Nelson", you'll get a couple of hits on me.

[ChiefEagles]

My son gave me a lot of these.  Cut hole in backboard under layout and flush mounted.  Works great to plug in and unplug.

 

[Birds]

So I was working on something the other day when the light bulb goes off... AMP connectors!  High amperage and high voltage connectors with multiple pins!

It appears to me that these should be able to handle running trains from 0-20 volts DC and be able to handle up to 17 amps if the wire is sized correctly.  But I would appreciate someone double checking the specs to make sure if I am understanding this correctly.

The 925450-1 recepticle, and 925451-1 plug, has 18 pins and appears to handle up to 17 amps.

http://catalog.tycoelectronics.com/TE/bin/TE.Connect?C=12899&P=&M=LIST&BML=10576,17560,17579,17772&LG=1&I=13&G=G 

Link to specs is below.

http://ecommas.tycoelectronics.com/commerce/DocumentDelivery/DDEController?Action=showdoc&DocId=Specification+Or+Standard%7F108-1032%7FB%7Fpdf%7FEnglish%7FENG_SS_108-1032_B.pdf

 

• The plug appears to be rated up to 17 amps (stated on page 2 in section 3.3.A)
• The plugs resistance appears to have been tested with 12 gauge wire using a 12 amp load (page 3 in the top row of boxes)
  
• Page 5 shows a chart of temps versus current.  What I understand from this is that when using correctly sized wires for the current being used (to prevent the wires and pins from heating up), and using the plugs at normal household temperatures (the plug's thermal limit is 221 degree F), it appears the connector should be able to carry that 17 amps without a problem.

Thanks,

Chris 

[lionelsoni]

Those should be fine.

They do look very much like the Molex connectors.

[Birds]

Bob,

Thank you for looking at those.

Would you recommend brass or phosphor bronze for the contacts?  I was thinking brass. 

The specs for the AMP connectors get confusing to me because they initially say 18 amp max, but then the fine print starts talking about lower current limits due to temperature rises from increased current, and also when using connectors with a higher number of circuits.

I did find Molex connectors that go up to 15 connections.  The downside is that the Molex connector's maximum current rating is 11 amps.

http://www.molex.com/cgi-bin/bv/molex/jsp/products/listview.jsp?query=&offset=0&BV_SessionID=@@@@0439857686.1179332492@@@@&BV_EngineID=cccdaddkmdjmfkicflgcehedffgdfmk.0&channel=Products&Lang=en-US&sType=z&fs=productname:mlx,categoryid:CRIMPHOUSINGS&autoNav=1&path=cHome%23%23-1%23%23-1%7E%7EncCRIMPHOUSINGS%23%230%23%23u&npp=40&Itemlist= 

Thank you,

Chris 

[lionelsoni]

I don't see a lot of difference.  With 13 amperes through each of 9 pins and 14 AWG wire, the A-MP connectors are good for 13 amperes, compared to 11 amperes for the Molexes.  In practice, you can safely assume considerable diversity:  It is very unlikely that more than a few circuits will carry the full current at any one time.  So the maximum current for any one circuit for both brands is probably a few amperes more, judging by the 14-ampere limit for the 4-circuit Molex.

Brass should be fine.