Speed Controller

[jward]

You state that the track runs around the room. How long a track are you running? Are you using a feeder buss with connections to the track every 3 to 5 feet? Have you soldered the track connections? The length of track may be just too long for the transformer you are using and is overheating when trying to supply the amperage required by the engine if you haven't done the proper set up.

perhaps a quick lesson on electrical theory is in order here. You stated that the length of the track would increase the current draw on the power supply. ohm's law, the foundation of electrical theory, say just the opposite. here's why:

assuming only one set of feeders to the track, the length of the track would increase resistance in the circuit. according to ohm's law, current (amps) equals the voltage divided by the resistance. thus, lengthening the track decreases the amperage draw on the power supply. it can also cause the locomotive to slow noticeably the further away from the feeders it gets.

one needs to be very careful giving electrical advice.    saying  the wrong thing can have disasterous consequences for those who follow the wrong advice.    at best, bad advice distracts from actually solving the problem at hand.

with regards to the original poster, is your setup dc or dcc? they are two completely different control systems, and need to be approached differently.

the overheating of the controller indicates that something is drawing way too much current.. the burning smell also indicates this.

do you have a second locomotive? if so does it also overheat the controller? can you test your locomotive on another layout? if so, does it also cause that controller to overheat? does the controller overheat when the locomotive is not on the track?   does it overheat when completely disconnected from the track?


let us know the answers to these questions, and we'll have a pretty good idea where to look for the problem.

[aramirez87120]

 Hello,

Thank you all again for all your expertise. 

I have a DC Set Up.  I do not have a second locomotive.  I am trying to find a local store to test my locomotive on (have not done this yet). Does not seem to over heat when the locomotive is not on the track.  I checked the track for resistance and did not find any.  Tested the track voltage and it read a maximum 12V with the directional switch to forward and 7 volts with it backward.  With the switch forward the locomotive moved very slow.

I did realize that one of the wall adaptors was faulty, so I replaced that with a new one before conducting these test.  I am leaning towards the idea that I have a bad locomotive now.  Thoughts?

[rogertra]

Brand name and model of your "speed controller" would be very helpful.

[aramirez87120]

Bachmann item No. 46605A

[jward]

are those voltage readings with no locomotive or cars on the track? if so, the voltage readings should be about 12v in both directions at full throttle, with nothing on the track, you effectively have an open circuit, and your resistance readings between the rails should be as high as the meter can read, approaching infinity. if you get different reading than that, then something is shorted somewhere.

note: do the resistance reading with the controller disconnected from the track so you aren't reading the internal resistance of the controller itself.

the locomotive itself, assuming ut is HO guage, can be tested with a 9 v battery touched to the wheels.

[rogertra]

Bachmann item No. 46605A

That's part of the problem.  It's cheap.  

Not owning one and just going by photos on line, it appears that the wires going to the track come from the throttle via a 1/8 mini stereo cable.  i.e., two conductors terminating at the throttle in a male 1/8 mini stereo plug.  Dunno how that connects to the track as I do not use set track.

Try replacing the cable, you could have a short in the 1/8 mini connector, it's not unknown. Don't worry about the cost of the new cable, they're not expensive but do purchase one from a reputable audio store, not your local dollar store outlet.

[Joe Satnik]

Dear aramirez87120,

I understand the internal circuitry of that controller fairly well.

I'm surprised no one has mentioned "LUBRICATION", or lack thereof,

which slowly increased the current draw enough to overstress and burn out controller components,

but not quickly enough to trip the internal circuit breaker before damage occurred.   

Sorry, but you have burned out the forward direction circuitry in your controller. 

An electrical technician or engineer could replace the burned out (1970's style through hole) components.

Not sure that would be cost effective, though, given auction site prices.   

Hope this helps.

Sincerely,

Joe Satnik

[jward]

joe, I am assuming you are talking about lubrication of the rheostat, with tv tuner cleaner?

the only problem with that theory is that the op has stated these problems are developing after a couple weeks in service. in this case, lubrication would probably not be the problem.

[Joe Satnik]

Sorry I was unclear.

Clean and lube the locomotive periodically and check that the rest of the cars roll freely.

Increased drag (friction) causes the motor to draw more current from from the power pack.

There should be some clean and lube instructions somewhere, including which lubes to use and how often.   

Hope this helps.

Sincerely,

Joe Satnik

[jbrock27]

Jeff is right, the resistance measured between the rails (make sure measured with power off) should be near infinite.
I agree with Roger, this controller you have is inferior.  In the end, if you have to obtain a new one, go with something from MRC and dump this one.
I agree with Joe S. about point of cost effectiveness.

aramirez8712-Have you taken meter measurements from the DC contacts on controller itself, with the wires disconnected that got to the track?  Checking the voltage in forward and then in reverse?

PS-SEARS recently had CRAFTSMAN meters on sale for $11.99-a good buy in my book!

[jbrock27]

...Actually check that, you may want to save the B'mann controller to make use of the AC terminals, as long as they check out ok on your meter for what they are rated for.  Good for hooking up to switch machines and lights and I am sure other AC driven items.

[Joe Satnik]

One thing nice about the controller head is that it is so light that it takes very little postage to ship (for sales delivery or repairs).

Throw it in a small padded envelope and off it goes. 

This is assuming your wall-wart adapter (transformer) is still in good shape, and stays home, awaiting a new or repaired controller head. 

If red LED on the controller glows brightly and steadily, it is likely that the transformer is still OK.   

Hope this helps.

Sincerely,

Joe Satnik