Lionel O-Guage Engine Impedence/Resistance

[Anonymous]

Crew,

I have just finished constructing a layout, and there are no shorts in it. I have 16VAC around the loop (minus locomotive). When I place the locomotive on the circuit, it does nothing. IF I retest voltage with train on it, it is less than a volt between the inner leg/outer legs.

The locomotive had been working fine for the past several days. I ran an ohm check across the locomotive, and I'm only getting about 3 Ohms which might well indicate a short circuit. Any idea what it (the resistance between the wheels and the middle leg contact) should be?

Your wisdom is greatly appreciated.

Shane

[wrmcclellan]

Shane,

Welcome to the CTT forums.

Your question depends upon the locomotive - traditional AC style motor or a modern unit with DC can motor. What locomotive is it and when was it manufactured?

Sounds like you do have a short in the loco.

Regards,
Roy

[lionelsoni]

It's very hard to say exactly what you should see--it would differ greatly among models and even with the armature position of the motor. But 3 ohms is plausible and a bit high for a short circuit. You say "the locomotive had been working fine". Have you tried it again off the new layout, either on a loose piece of track or upside-down with wires touched to the frame and pickup? Is it possible that you have a mechanical problem? What kind of locomotive is it? You could have picked up some tra***hat has jammed the gears. Magnetraction locomotives do that easily.

[eZAK]

[#welcome]Shane,

We need more info. please.

What type of engine is it, model #, Yr Blt.?

What type of transformer are you using?

How big is your layout?

All these as well as an internal problem will affect the cause and treatment.

[Anonymous]

Guys,

Thanks for all the feedback.

I tried the assembly this am on a new short section of track with the same results. ERgo, the layout doesnt appear to be the problem. My only two other sources of potential failure are the control box and the locomotive. Nothing has happenned to the locomotive at all to cause problems. (hasnt fallen in toilet/crashed hard, etc....)

After reading your ideas/reviews, it brought to mind that I had also replaced the wire from the control box to the track, including hacking into the Lionel box, unsoldering the old wire and soldering in a new one (old wire was only about 4' long).

It is my only power controller, so I dont have a means to check it. It is supplying out the correct voltage, but when the train completes the circuit, nothing happens. I guess theres an outside chance the power supply got messed up in the process (makes alot more sense than the train failing mysteriously with no cause). Theres a train store here in north Dallas. I'll try to take my locomotive over there to try it on their test track.

I tested the power supply output this am, and I get a proportional signal from 1 to 16VAC depending on where the rheostat sits. It looks like its working. I suppose, however, that the thing might be able to provide the voltage differential, but not support the current flow?? Interesting possibility. Reminds me again why I studied mechanical engineering in college instead of electrical.

As for what it is, I'm not sure the exact details. I just got into model RR a month or so ago. I built a 6" wide shelf of rough cedar going around my boy's (8 mo old) room. I've been having a disturbingly good time with it all. The boy seems pretty oblivious. The locomotive was made in the 50's, weighs a couple pounds, is all metal, Lionel, and has the number 2018 on the side, which I suppose might be a model#.

I'll keep you posted how this turns out. Thanks for the encouragement and assistance so far.

Shane

[wrmcclellan]

Hello Shane,

The 2018 is a Lionel engine from 1956-59 or 1961. These engines are pretty good runners and very reliable. Lubricate the motor and gear bearings with some light oil.

Which Lionel transformer (power supply) do you have? There should be a number on the top. You also said you went inside the unit to add longer wires. This does not sound like an older transformer unless you added a longer power cord? The 10-18 VAC connections are typically via finger screw posts on the top or rear of an older Lionel transformer.

I live in Richardson. Send me an e-mail if I can be of any assistance.

Regards,
Roy

[Anonymous]

Futher update:

I took my locomotive to the local train shop in Addison, TX. Turns out, nothing wrong with loco. Runs like a champ (just like it probably has since the late 50's). After much further evaluation, I found that in the soldering process while "optimizing" my power supply rig, I had all but severed one of the lines on the PC board. Ergo, its able to provide voltage drop, but not support the current flow. Makes sense, in hindsight. Now that I have all that addressed, the rig is running like a champ.

Thanks for all the help, folks.

shane

[wrmcclellan]

Shane,

Thanks for the feedback and solution to your problem. Have fun with your trains!

Regards,
Roy