# plug and play question



## Biblegrove RR (Jan 4, 2008)

both wires coming out of the engine are black on the female plug, which is positive/negative?
I am wiring up a drill battery in a trailing car and don't want to get it backwards.


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## Totalwrecker (Feb 26, 2009)

John you need a voltmeter. 
Set it on DC and touch the red and black tips to the plug contacts. The meter will give a positive read when the red probe is on the right contact and a negative read when reversed.


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## Biblegrove RR (Jan 4, 2008)

even if it has no power?


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## Greg Elmassian (Jan 3, 2008)

Basics: 

Hi guys, I have an Aristo xxxx loco (fill in the blanks) 

I want to run it from batteries/track/rocket fuel .... (pick one) 

OK, so I can guess it's an aristo loco, assumption one... and you want to run from battery and controller in trailing car, assumption two... 

First, set the battery/track switch to battery... then see if applying 10 volts DC briefly makes the loco go... now you can decide what your convention is, which pin for postive for forwards. 

These plugs have no standard, nor consistency. Also, you may want to be sure the battery connections are isolated from the rails, Aristo often only disconnects one track pickup. This can cause problems. 

You really have to check out EVERY Aristo loco to see how it is wired when you make modifications, or run from battery. The testing at the factory and conformance to standards is minimal. 

Regards, Greg


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## lownote (Jan 3, 2008)

I'd second what Greg said. aristo's plug and play socket and track/battery switch are both great ideas, and sometimes they work, but in my experience they are often full of random wiring variations and undocumented oddities. On one of my three aristo locos I just gave up and tore the whole circuit board out and wire dit all directly. On the other two, it works mostly as advertised, though I've never actually tried wiring either for battery


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## rmcintir (Apr 24, 2009)

Once you have set up your Aristo locomotive to run, powered from the MU cable, NEVER, I mean NEVER set the switch to track while the battery is connected. You will let enough smoke out of the Aristo circuit board to put the new smoke generators to shame. 

If I wasn't clear, NEVER set the switch to Track with the battery connected or on some locos turn the "Motor" on. There's some clear labeling for ya! 

BTW, I do love my Aristo locos, this is one area which is sadly designed.


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## Biblegrove RR (Jan 4, 2008)

wow, did this happen to you? I have a friend that does that all the time to save battery power. Uses it as an on/off switch and it hasn't smoked.... ? OF COURSE it was on non-powered track!


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## Greg Elmassian (Jan 3, 2008)

John, the battery/track switch wiring is also random... MOST times it disconnects one track pickup and never disconnects the battery... i.e. both battery leads are always connected to the main circuitry, and one of the track pickups is always connected, and the switch just interrupts one track pickup wire, BUT, there have been variations.... It's especially rankling since the switch used is normally a double pole double throw and it would have been simple to wire it so it was EITHER one or the other, and both leads in both cases... but, that's Aristo wiring. 

Regards, Greg


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## Biblegrove RR (Jan 4, 2008)

HOLY MOLY! NOT as simple as plug and play eh? IMAGINE THAT! This hobby frustrates me. 
OK so I just opened it back up and disconnected all 4 of the wires to the track pick ups according to the OVGRS site's instructions. NOW, I have to verify the MU plug matches my MU plug as far as Pos/Neg wiring and then simply plug in my battery and go? ("simply" I can't believe I said just that)


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## rmcintir (Apr 24, 2009)

Even if track is unpowered it very bad to switch to track power with battery connected. The unpowered track may have reversing loops, wyes, etc. that will short the track together. This short may translate to a battery short.


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## Biblegrove RR (Jan 4, 2008)

no problem now that the track pick ups are disco'd.....


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## Biblegrove RR (Jan 4, 2008)

A dealer just told me it does not matter which is pos. or negative when connecting the MU plug to battery because this will dictate the direction only and it won't hurt it...?????


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## Greg Elmassian (Jan 3, 2008)

He is right... but people then hook a second car to the other end of a loco and sometimes have problems... 

Basically, you should not care about the polarity if you are feeding one car. 

If you are going to use different locos with the same battery car, you might want to standardize the wiring so forward with loco "A" will give you forward with loco "B".. 

By the way Russ's admonition is good insurance. 

Regards, Greg


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## rmcintir (Apr 24, 2009)

This is what happens when you place an SD-45 on unpowered track with the switch set to track. The locomotive had a fused battery connected to the MU plug with my RC receiver in the plug-n-play slot. I have since reduced the amperage of the fuse. My locomotive receiver suffered no damage and amazingly, the Aristo board still worked after letting a significant quantity of smoke out. 










This picture was posted as a warning on the Aristo forums. I have also discovered an FA unit that had the front MU plug wired directly to the speaker connector. If it had been connected to power the speaker would have been destroyed. Double check all the wiring. QA problems can happen. 

I now use a DPST switch on the MU plug/track input. I need to be able to run my locomotives on both battery and track power and that is the only safe way.


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## Del Tapparo (Jan 4, 2008)

What did you expect? It says right on the board "SMOKE"! "SOUND-PWR" must refer to the sound it makes when the PCB is smoking under power.


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## Biblegrove RR (Jan 4, 2008)

IT WORKS!









The direction on the transmitter points to the right when engine moves forward, is this correct? I changed the plugs on the battery and it stayed the same too...


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## Greg Elmassian (Jan 3, 2008)

Most people use right = forwards, but it's your train, you can adopt any convention you want. 

I'm used to DCC where forward and reverse are indicated with those words. 

Regards, Greg


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## rmcintir (Apr 24, 2009)

Posted By Greg Elmassian on 16 Sep 2009 05:06 PM 
Most people use right = forwards, but it's your train, you can adopt any convention you want. 

I'm used to DCC where forward and reverse are indicated with those words. 

Regards, Greg 
Interesting, I use < and > symbols on my own system but maybe I will make a configurable option to display Fwd and Rev if desired.


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## Greg Elmassian (Jan 3, 2008)

A number of people say they don't care, but I like to know for sure when I start out what direction I am going. 

I think it's a good feature.. 

Also, helps when consisting locos... I like to drive the locos together and then consist and take off as one... 

Regards, Greg


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