I've Got A Problem

[Flintlock76]

Not an earth-shattering one, but I need some ideas.

I've got a post-war 6466W whistle tender and the solenoid's taken on a permanent magnetic charge, so much so the activation plate won't drop even if there's no current to the tracks. When I power the tracks the whistle sounds.

For the moment I've got the solenoid propped up against a screwdriver de-magnetizer to see if that helps. I'm going to leave it for several days, but if anyone has any ideas on how to kill the magnetism in the solenoid I'd appreciate the input.  

Thanks!

[8ntruck]

Since the slugged relay responds to the D.C. whistle signal, think it would help to reverse the popularity by swapping the relay coil wires, or mabe swapping the posts on the transformer?

 

Disclaimer:  I am a retired mechanical engineer.  I have enough knowledge of things electrical to be dangerous.  The only thing I know for sure is that the electrical devices run on magic smoke.  Do something to let that magic smoke out, the electrical device quits working.

I wonder if the armitature (bottom plate) is magnetized?  Can you get that loose to see if it is?  Your demagnitizer might work on that if it is magnetized.

[Flintlock76]

Thanks for the suggestions, I'll give them a try!

 

[ADCX Rob]

Flintlock76

...the solenoid's taken on a permanent magnetic charge, so much so the activation plate won't drop even if there's no current to the tracks.

Cut a square of masking tape the size of the activation plate and set it on top of the plate sticky side down.

[Flintlock76]

Another good idea!  Thanks!

[Flintlock76]

Just an update, now the thing's got a short in it and it beats me where.  What the hell, it's 70 years old and was probably never expected to last this long anyway.

I'm just going to set it aside for a while and try it later.  Worst comes to worst I'll just update it with a modern sound system.

[8ntruck]

I've had other late 40's or early 50's tenders that had a hidden, intermittent short that would cause random actuation of the e-unit.  Turned out to be a crack in the insulation on one of the tender power leads that would occasionally touch the tender chassis where it passes through.  I only found it when I saw a spark under the tender when one of the mystery e-unit actuation happened.

[Swiss-Colorado-Lines]

Flint,

 my guess is most likely the relay coil is shorted internally. These coils are made up of coiled enameled wire. Vibrations over the years may have rubbed off the enamel somewhere. It will be impossible to see.

 If you can get a replacement relay, it could be just the ticket!

Paul

[Flintlock76]

Thanks for the suggestions gents!  I may, may, try re-wiring the unit, it's got 70 year old wires in it after all even though they seem to be in good shape, that is no cracking or splitting of the insulation. 

But Paul has a good point, it could be the coil in which case I'll never find the problem.

Hey, it's just as easy to replace the whole thing with a modern electronic unit too. I'm not so much a purist that EVERYTHING has to be original.