I have a post war whistle relay here and have tried all the tricks but nothing works to de-magnatize the relay. I even took it apart and run a de-magnatizer over the relay solenoid head. Cleaned all surfaces. It won't stay stuck when just pushing the bottom up, but will after DC voltage is applied and released. It stayed stuck over night when left.
Rob
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If you can determine what polarity DC you are using for your test, try reversing the polarity and operating it with a pushbutton for a number of times.
Place a piece of masking tape cut to fit on top of the armature plate where it meets the magnet core and it won't stick anymore.
I can say from a point of view not limited to trains,once a relay becomes magnetized it is junk.Nick
I can say from a point of view not limited to trains,once a relay becomes magnetized it is junk.Nick
Nick, I'd be happy to take that junk off your hands. I have used three methods to demagnetize steel. Basically you want to rearrange the molecules. Heat works, you don't have to get it red hot but definitely too hot to touch like 400-500F. Mechanical shock works. If you have a screwdriver that has gotten magnetized bang it against something hard like your vise. The best way is pass it through a AC field. Google degaussing coils and you will see some. There are some made specifically for small items like tools. If you had a large spool of wire you could make your own and there are many examples of homemade ones on the web.
Pete
I tried all the tricks listed. What finally worked was the tape like Rob mentioned. I probably did not use enough heat.
Rob
The tape works every time.
Attempts to degauss usually don't work - you have to realize that the coil is continuously energized with AC already whenever the track is powered up. The shading ring on the core shorts the magnetic field until there is a DC offset (+ or -) element (1.5 volts according to Lionel) which results in the armature plate lifting up.
you have to realize that the coil is continuously energized with AC already whenever the track is powered up. The shading ring on the core shorts the magnetic field until there is a DC offset (+ or -) element (1.5 volts according to Lionel) which results in the armature plate lifting up.
I've always wondered why those relays didn't chatter...
What is a shading ring and where is it ?
Thanks Rob. Excellent explanation.
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