# Alternative Jack size for lighting power?



## Eilif (Nov 6, 2017)

This year I added a few lighted elements to my O Gauge Holiday Layout. Mostly I was just wiring 5.5mm. plugs into formerly battery powered buildings and vehicles.

However, I found that the 5.5mm jack's and plugs (used because if was the Menards standard) and the wires they came attached too were quite thick and bulky and often difficult to make lay in the right position.

My question is whether there is any reason not to use 3.5mm stereo plugs and jacks in the future? I figure I could just buy a bunch of m/f 3.5mm audio extenders to get plenty of wired plugs and jacks that are just as cheap and much smaller.

Thoughts?


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## MichaelE (Mar 7, 2018)

Audio cables are not rated for current. As long as you don't smoke one I suppose they could be used.


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## Eilif (Nov 6, 2017)

Thanks. What's the fundamental difference regarding handling current? Is it more likely to overheat because it is shielded? It's not much voltage (around 3 volts) but it will be on alot.

Are there better small attachment methods for powering small items that can be easily detached?


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## MichaelE (Mar 7, 2018)

Audio cables are typically very small gauge even if the outer jacket makes them look larger. As I said, as long as you don't smoke one with too much current they should work fine.

Molex connectors that you wire yourself or barrel jacks and plugs would be my first choice.


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## gunrunnerjohn (Nov 10, 2010)

Any battery powered building won't overload audio cables, I'd say use what you like. FWIW, many small portable devices use similar cables.


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## Eilif (Nov 6, 2017)

@gunrunnerjohn 
That's what I was hoping. I'd seen many things powered by similar size plugs. I've found a variety of alternate small plug sizes, but even the one's with small plugs seem to have plug housings that are almost as thick as the 5.5mm's I already have. Smaller cords yes, but if the plug housings are that big I might as well stick with the 5.5mm's Iv'e got.

On the other hand I've found some M/F 2.1mm audio extender cords with a very small profile jack housing. Small enough to sit nicely under the ground clearance of a 1/43 car. I figure I buy a bunch of them and I can cut/solder/etc them into whatever configuration I need. 



MichaelE said:


> Audio cables are typically very small gauge even if the outer jacket makes them look larger. As I said, as long as you don't smoke one with too much current they should work fine.
> 
> Molex connectors that you wire yourself or barrel jacks and plugs would be my first choice.


Molex looks interesting. Is it sturdy enough to stand up to repeated disconnection and reconnection? This is a setup that not only gets put together and then disassembled each year, it also may get rearranged several times while setup.

By Barrel Jacks, do you mean 5.5mm stuff? Those are what I already have and they're too bulky IMHO. I did find some wired up with more flexible wire, but still, I'd like jacks small enough that they can be hidden under the 1/43 and 1/48 vehicles they are powering.


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## Lemonhawk (Sep 24, 2013)

You could also use 0.1" crimp connectors also (see Pololu - Connectors for an example). They also sell the crimper so they do not require soldering (A good crimp tool is the secret to success here!


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## Eilif (Nov 6, 2017)

Crimp connectors look interesting. Do I understand correctly that the wires are crimped into the connector that can than be easily connected and disconnected? 

Soldering is no problem for me (just soldered up an adaptor cord for a battery jumper last night) but I do like "easy."


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## Lemonhawk (Sep 24, 2013)

Yes, the plastic holder is common, but you get male and female pins that are crimped to the wire then inserted into the plastic holder. There is no key so its up to you as to how you swap the male and female pins around. Here is a close up of a 4 pin connection, in this case one of the connectors includes a 1/4 watt resistor that connects in series with the panel LED, thus I can change the value of the resistor by pulling the pins and putting in a new resistor (I think I may have soldered the resistor directly to the pins I can't remember but all the wire connections are just crimped (which is a preferred method) . This has been operating for several years without a failure. The crimp tool is the key as it need to crimp to the insulation and the wire all in one shot. Kits of the housings and pins can be bought at Banggood and other places, but its a great way to make connections. If your taking track power then use Power Poles, common housing and pins - no male and female pins!


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