Phone/ethernet cables between cars?

L

Lylat1an

Registered
8 Nov 2020
30
1
Graham, WA
I'm thinking that a phone or ethernet cable would be convenient to connect electronics between a tender and locomotive, or between other cars.

But are the wires inside too thin for this purpose?

Specifically, I want to connect a Tam Valley DRS1 system's receiver in a tender to a sound decoder in the locomotive, along with a backup light in the tender controlled by the locomotive's decoder.

Might a 4-wire telephone cable have sufficient gauge wires to properly carry the signals and voltage, or perhaps I could use an ethernet cable with 8 wires and combine the cables into pairs they're too small on their own?
 
ntpntpntp

ntpntpntp

Registered
24 Oct 2009
7,344
260
57
UK
My immediate thought is the cores are probably too thin, plus as a cable the whole thing would be rather inflexible?
 
Greg Elmassian

Greg Elmassian

Registered
8 Mar 2014
4,445
660
San Diego
www.elmassian.com
The connector is not designed to have cable movement, so the connector is a bad choice right off. Wire too thin for motor power also. Connector not designed for several amps of current.

Use multi pin "jst style" connectors:


 
L

Lylat1an

Registered
8 Nov 2020
30
1
Graham, WA
I take it USB cable wires would be too thin as well? Those cables are more flexible.
 
Greg Elmassian

Greg Elmassian

Registered
8 Mar 2014
4,445
660
San Diego
www.elmassian.com
the USB connector can handle more current, but typically the wires are not appropriate at all.

I gave you the best suggestion already, take the advice of people who have done it for years. There are other types of connectors also, but you keep looking at connectors whose main purpose is to carry data, not voltage and current. Also, because this is outdoors, you need something more robust in terms of contacts.

Also, I favor locking connectors for outside use, so they cannot vibrate loose, although you can clip off the locking mechanism if you are in the school of thought that wants "breakaway" connections.

Greg
 
L

Lylat1an

Registered
8 Nov 2020
30
1
Graham, WA
Exactly
 
Greg Elmassian

Greg Elmassian

Registered
8 Mar 2014
4,445
660
San Diego
www.elmassian.com
too small to be scale... you want 4 conductor, you might be able to find a DIN connector.

search "4 conductor miniature din connector" ..... this is the diameter of the mouse and keyboard connectors before they went to USB.

there are smaller ones, but now you are back to running into current handling capability.

Greg
 
L

Lylat1an

Registered
8 Nov 2020
30
1
Graham, WA
Do you mean DIN as in PS/2 connectors, or the larger DIN connectors used on IBM PCs and their clones?

I work in an e-cycle warehouse, and have access to plenty of PS/2 cables.
 
Greg Elmassian

Greg Elmassian

Registered
8 Mar 2014
4,445
660
San Diego
www.elmassian.com
I will revise: this is the diameter of the mouse and keyboard connectors immediately before they went to USB.

yes, ps/2 type, not the original 5 pin din used on the very first PC's

(also those were 5 pin, the ones I indicated are 4 pin)

still larger than scale.
 
dunnyrail

dunnyrail

DOGS, Garden Railways, Steam Trains, Jive Dancing,
25 Oct 2009
18,207
3,735
72
St.Neots Cambridgeshire UK
Sorry, I was looking for a solution that might look like a prototypical tender connection.
Have a look at HO 4 way DCC connectors, though the wires are quite thin for small locomotives they are just fine and look pretty good as well. I have used them in a 3 car LGB DCC powered railcar.
 
-bbbb

-bbbb

Registered
21 Dec 2017
375
109
Idaho
I was able to successfully use an RJ45 cable between a tender and loco to bring battery power from the tender to the RC loco.
But I needed to remove the external shielding to get the proper flexibility:
rj45.JPG
I used a couple of the wires to power the train (motor, front light, and sound) with 9 volts, and a couple of the other wires to power the fire box lighting:
IMG_6855.JPG
The loco motor/light/sound and the fire box lighting both have separate battery supplies in the tender, and separate power switches as well:
rj452.JPG
I've had no problems with this system. I can't remember if I doubled the wires for the 9 volt motor connection. If I did double the wires I merely would have put a jumper between pins of the pairs in the female connection, and connected the same pairs inside the tender as well.