Noisy transformer

@Ken Orlowski posted:

Does anyone have any tips for reducing or eliminating the loud humming noise from an American Flyer transformer?

The one in particular that I have noise trouble with is a #22035 transformer.  I have tried tightening the two screws down that holds the coil to the base, but with little success in noise reduction.

Sorry, don't know anything about that particular transformer, but one of the go-to DIY techniques I've seen for reducing mechanical noise is vibration isolation. Tightening the mounting screws *will* eliminate any rattling from a loose junction, but is also more likely to better transfer vibration to the larger "sounding board" of the case.

Would it be possible to create (or enhance) rubber mounting dampers of some sort? I have in mind rubber rings between the coil and base, and between the head of the screws (or washers under the heads) and the base on the outside. You may need to enlarge the holes in the base to avoid the screws' contact with the base, and you want to make sure the outside heads of the screws do not rest on the layout. Ideally (if you can find some), you could use those little one-piece mounting 'donuts' that are designed to pop into holes in the case and provide isolation inside, outside, and between the screw shafts and base.

Also, there should be additional acoustic isolation between the transformer and the layout supporting it, usually by way of cone-shaped rubber 'feet' with mounting screws in the middle, but in a pinch by just resting the transformer on a half-inch or so sheet of foam (be sure not to obstruct any cooling vents).

About the only other measure I can think of would be to add dampening padding inside the case, especially on any sheet metal surfaces that might otherwise add sounding board surfaces that can radiate any internal vibration, if there's enough clearance. Car manufacturers make good use of self-stick sheets of such sound deadening material on sheet metal surfaces, and if you can lay your hands on some (from a body shop, etc.) you may be able to damp out some additional vibration/sound. In any event, good luck!

Hit with the palm of your hand.  Do not break the case or you hand.   Works temporarily on my Lionel LW.

Charlie

AF transformer

Here's a link to a American Flyer transformer manual that mentions if humming check for loose wood wedges. I would pop the top and see how the coil is supported and maybe wedge in some wood shims and see if you can stop the hum.

the metal plates that hold that transformer together become loose this is what causes the hum or vibration you need to tighten the brackets!

Alan

1

Hmmm. I thought transformers were SUPPOSED to hum

the 22035 should have a wooden base on the inside which may be rotted or burnt out.

Gunny

Hummm!!!  May be a candidate for the recycle bin.  Any transformer, the primary and secondary wiring can, at the least, bleed through.   A potentially dangerous situation.  Some of this stuff approaches 100 years.   Safety meeting of the day.  Mike CT.  

Teach it the words? 

I've had analogous problems with a 494 beacon mounted on a Marx demo layout, where the vibrations from the beacon motor resonated through the plywood top.  I wound up fabricating feet from chunks of self-adhesive dense rubber foam, which helped considerably.   You might want to give stick-on rubber feet a go...

Mitch

@Mike CT posted:

Hummm!!!  May be a candidate for the recycle bin.  Any transformer, the primary and secondary wiring can, at the least, bleed through.   A potentially dangerous situation.  Some of this stuff approaches 100 years.   Safety meeting of the day.  Mike CT. 

Point well taken.

    "No user serviceable parts inside"

Although these words did not appear on transformers for at least 60 years after they were first introduced they really apply to all transformers, whether ancient, brand-new, or somewhere in between.

As far as the situation with this 22035, Just fiddling around inside the case with anything could cause the failure that Mike has mentioned (bleed-through), primarily because of the age of this thing, and the likelihood of crumbling insulation and insulators inside.

Play it safe.  Don't open it unless you're prepared to replace all of the insulating parts, which may or may not be available in today's world, in any case.

More importantly, don't even try it unless you have the skill, talent and experience to do so safely.

Mike

How does one get experience except by taking one apart?

I have taken apart several of my transformers despite no prior experience. I found a lot of good reference material online and on this forum for most of  the Lionel ones (V, Z, KW). Definitely do not mess with the nasty chemicals coating the core--they have been the source of many cancers. Replacing rollers, or wires with rotten insulation, or a bad binding post, are just not that difficult. Can't speak to solving the hum issue, but I do not favor scaring people off from learning how to keep these running their trains.

@Ken Wing posted:

How does one get experience except by taking one apart?

Yeah, I was thinking much the same.

Sure, when you're dealing with line voltage rather than the sub-20 volts we typically deal with on our layouts, extra caution needs to be exercised. However, replacing vintage power cords that are cracked and crumbling from age is commonplace, and IMHO there are in fact user-serviceable (or at least -repairable!) components in the typical transformer, at least as much as there are within the typical engine.

By all means, consult available guidance before diving in, and I agree that the core transformer components should not be disassembled or messed with, but I don't think the interior of the case should be off limits per se. Minor example: one of the throttles on my ZW was going dead at full throttle, so I opened up the case. Turned out a molded stop had broken off, allowing the wiper to drop off the exposed coils, so I drilled and tapped a hole to insert a screw to serve as a substitute stop. Easy fix, but one that required opening the transformer to see what was what.

Thanks to you all for some helpful tips.  I ended up using some soft washers on both ends of the two mounting/hold-down screws on the coil.  It reduced the humming noise somewhat, but not completely.  The humming noise was definitely coming from the thin metal plates---there is just so much you can do to clamp those together tightly.

Thanks again, Ken

@Ken Orlowski posted:

Thanks to you all for some helpful tips.  I ended up using some soft washers on both ends of the two mounting/hold-down screws on the coil.  It reduced the humming noise somewhat, but not completely.  The humming noise was definitely coming from the thin metal plates---there is just so much you can do to clamp those together tightly.

Glad you got some relief, Ken. I should have added to my earlier reply that the process of sound deadening is a lot like stacking sandbags -- each can add something toward the desired outcome, but seldom completely solves the problem. You just have to keep 'stacking' until you either get the hum to an acceptable level, or you run out of 'sandbags'!