Multi-way cable connectors

[MarkSG]

I'm not entirely sure what the correct term to describe what I'm looking for, so maybe it's easier if I describe the situation...

 

I'm currently building a small-ish shunting plank. Today, I fitted the point motors (Hattons PM-01s - I've decided to stick with analogue solenoids because they're simple and cheap!) and wired them up. At the moment, they're hard-wired into the point controller which sits on a shelf next to the layout. Which is fine, it works.

 

However, this is intended to be a portable layout, so, rather than having wires permanently connecting the controllers with the layout, what I want is a plug-in connector that I can insert between them. That way, when in transit, there are no wires outside the baseboard frame, and when it's time to set up all I need to do is plug the controller into the layout.

 

I'm sure that's simple enough, and I'm sure plenty of people already do this with portable layouts. What I'm after, therefore, is suggestions for suitable multi-way connectors that will allow a simple "plug and play" connection between the controller and the layout.

 

For reference, there are six points on the layout, so that's 13 wires in total (two each plus a common return). Ideally, I'd like a connector that can handle all 13 wires in one plug/socket combination, or, if that's not practical, maybe two or three. I don't need to include the power in this as I've already got a separate plug-in connector for that.

 

Any suggestions?

[Butler Henderson]

21 minutes ago, MarkSG said:

For reference, there are six points on the layout, so that's 13 wires in total (two each plus a common return). Ideally, I'd like a connector that can handle all 13 wires in one plug/socket combination, or, if that's not practical, maybe two or three. I don't need to include the power in this as I've already got a separate plug-in connector for that.

Multiway D connectors are often used

Rapid being one supplier https://www.rapidonline.com/Catalogue/Search?Query=connector&Tier=D Multipole Connectors

[wandering blue]

 

Compile from Speakon, XLR, or Anderson Powerpole.

 

See this thread :

 

 

Recommend a robust plug.

 

 

  

 

[sharris]

It is unfortunate that the in-line link to the thread has picked an image of the one connector not to use.

 

The connector shown is used for mains voltages and must not be used for low voltages.

[Tony Cane]

While it can be argued that the D-type connector recommended is not intended for the level of current used to switch a solenoid point motor, it is  cheap and convenient to use.

 

If you use the D-type I would recommend using a pre wired cable such as this

 

https://www.ebay.co.uk/itm/2m-25-Way-RS232-Male-to-Female-Straight-Cable-Lead-Serial-Pin-DB25-D-Sub/330722815988?epid=1311725458&hash=item4d009daff4:g:qiMAAOSwcu5URpXQ

 

 

Cutting the cable to  form plug to socket connection, fitting bootlace ferrules on the leads and then use a strip connector for connection to further wiring,  Also I would use two conductors for each "wire" in the circuit, a 26th connection can be obtained by using the shield.

The main advantage of this is that wiring to the connectors is already done, and the colour codes of the wires aids getting the correct connections made.

 

Please note that a male to female lead is required and that if the similar 9 way cable is used that on types described as a nul modem do not have straight through connections, and may not have all 9 connections in use.

[cliff park]

The shield, or screen, in any screened cable is good for a common return and can usually carry very high currents due to the nature of its construction.

[sharris]

12 hours ago, MarkSG said:

...

For reference, there are six points on the layout, so that's 13 wires in total (two each plus a common return). Ideally, I'd like a connector that can handle all 13 wires in one plug/socket combination, or, if that's not practical, maybe two or three...

 

Browsing a few data sheets D-sub connectors are rated at 3 to 5A which should be enough for a solenoid point motor.

 

For this application, I would echo the suggestion to double up contacts, not just to ensure current carrying capacity, but if you are likely to be repeated connecting and disconnecting the cable should give more long-term reliability if repeated connection and disconnection wears the contacts - you'll get a bit of a back-up for a worn pin.

 

When choosing a D connector, I'd look at turned or machined pin rather than stamped- a bit more expensive but more reliable.

[Butler Henderson]

I have used D connectors without problem, as 7/0.2 wire is the best to use otherwise it gets quite difficult soldering the wires in place then yes some doubling on connections is advisable. Depending on how many actual connections there are the issue is more one of cable indentification. Once it was quite easy to source cables in masses of colours and colour combinations so having a couple of dozen of readily identified cables simply due to their colouring was easy.

[MarkSG]

4 hours ago, Tony Cane said:

Cutting the cable to  form plug to socket connection, fitting bootlace ferrules on the leads and then use a strip connector for connection to further wiring,  Also I would use two conductors for each "wire" in the circuit, a 26th connection can be obtained by using the shield.

The main advantage of this is that wiring to the connectors is already done, and the colour codes of the wires aids getting the correct connections made.

 

Thanks, the idea of using a male-female D cable and cutting it in half to create the plug/socket connector is one of those things that sounds obvious when you know about it but takes a bit of out-of-the-box thinking to come up with in the first place! Also the suggestion to double up on the connectors for redundancy makes a lot of sense.

 

I've ordered one, so I'll see how I get on with it when it gets here.

[Butler Henderson]

1 hour ago, MarkSG said:

 

Thanks, the idea of using a male-female D cable and cutting it in half to create the plug/socket connector is one of those things that sounds obvious when you know about it but takes a bit of out-of-the-box thinking to come up with in the first place! Also the suggestion to double up on the connectors for redundancy makes a lot of sense.

 

I've ordered one, so I'll see how I get on with it when it gets here.

Just watch what the wires are, could be finer than 7/0.2 so the current handling may be less.

[sharris]

7 hours ago, Tony Cane said:

While it can be argued that the D-type connector recommended is not intended for the level of current used to switch a solenoid point motor, it is  cheap and convenient to use.

 

If you use the D-type I would recommend using a pre wired cable such as this

 

https://www.ebay.co.uk/itm/2m-25-Way-RS232-Male-to-Female-Straight-Cable-Lead-Serial-Pin-DB25-D-Sub/330722815988?epid=1311725458&hash=item4d009daff4:g:qiMAAOSwcu5URpXQ

 

 

Cutting the cable to  form plug to socket connection, fitting bootlace ferrules on the leads and then use a strip connector for connection to further wiring,  Also I would use two conductors for each "wire" in the circuit, a 26th connection can be obtained by using the shield.

The main advantage of this is that wiring to the connectors is already done, and the colour codes of the wires aids getting the correct connections made.

 

Please note that a male to female lead is required and that if the similar 9 way cable is used that on types described as a nul modem do not have straight through connections, and may not have all 9 connections in use.

 

Note that the technical information for the linked cable states:

 

 

so there will not be enough pins connected for this application. Also remember that RS232 is a low current relative to this application, so as Butler Henderson suggested the pre-wired cable may not be up to point motor currents.

[Tony Cane]

Sorry Mark did not spot this in the spec when I looked for an  example.

 

This would appear to be more suitable.

 

https://www.ebay.co.uk/itm/LEAD-25-WAY-DF-TO-DM-3M-Cable-Assemblies-Computer-Cables-CJ57744/282975098029?hash=item41e2a154ad:g:BOUAAOSwdQdbAkzc

 

Hope you had not ordered  on my first recommendation.

These cable assemblies use to be more common, and cheaper, when in more common use.

It might be worth looking at other sources if price is an issue.

[Tony Cane]

This one from Rapid electronics looks to be good alternative

 

https://www.rapidonline.com/rvfm-sl-122-2-0m-m-f-rs232-extension-19-0615

[MarkSG]

Actually, I ordered one from Amazon rather than that precise one from eBay, and I did check that it had all pins connected before I ordered it as I noticed in the spec that not all of them do. So it should be OK when it gets here.

[H2O]

An alternative (I'm not saying it is better for this) is the following - I've not got one but looks to be as equal to the job as the 25 way D type connectors:

 

https://cpc.farnell.com/unbranded/pc333/36-way-centronics-plug-to-socket/dp/CS02364?st=centronics

 

36 way and 3m long, also has locking system so it shouldn't come undone.  By doubling up it would give 18 ways.

 

It is not clear if all 36 ways are connected or what the current ratings are (as per most computer data cables) but should be good for low power signals or short bursts of current (rather than power) connections, e.g. LEDs, train detectors.

 

PS It is assumed the internal wires are colour coded in these types of computer cable - any confirmation of that?  If not it makes connecting up the cut ends very tedious!

[sharris]

1 hour ago, H2O said:

 

https://cpc.farnell.com/unbranded/pc333/36-way-centronics-plug-to-socket/dp/CS02364?st=centronics

 

This was the traditional parallel printer cable (the PC chose to reduce one end to a 25 way d-sub as not every signal is used)

 

For its official use mostly the top line (defining 1-18 as the top) were data and control with most of the bottom line being ground, although 3 pins on the bottom are used for control - often implemented as  twisted pairs between signal on the top and corresponding ground on the bottom - if individually soldered you might be lucky with colour coding, but the plug and socket may alternatively be IDC connectors with ribbon cable which may be rainbow but if you're unlucky could be a plain colour (although you can count along the cores to work out which connector pin corresponds to which core).

Edited March 8, 2020 by sharris

[AndyID]

D subminiature connectors are fine for feeding solenoid point motors. The specified current ratings are for continuous current. Solenoid point motors only take very infrequent short-duration currents. It's highly unlikely that the connector contacts will overheat.