I was checking out a LHS that I had heard about but never visited before to see what kind of selection he had. He had a decent amount of trains stuff but nothing spectacular. There was a lower shelf that contained an assortment of old power packs and I had been looking for a cheap one to handle switch machines and other accessories on which are on the opposite side of the room from my main power source so I wouldn't have to run wire all the way around the room. I found one that was missing the throttle knob but that was of no concern to me since I wasn't going to use this for track power and the price was right ($5). From the size and shape of the thing, I'm guessing it was 40 years old, maybe more. Nothing sleek about it. The kind of stuff I remember from the 1960s. When I plugged it in, I heard a faint hum and there was a slight vibration in it. Is this an indication it is faulty or was that common for power packs way back when. The model name of the power pack is Unipack Special and the maker name was in script and slightly worn but I think it says Scintilla.
Yeah, old transformers would hum. I've got one that I suspect was from the Truman administration. It hums a bit, too. It says Lionel on it, and it's now in semi-retirement, powering only the Walthers traffic light sequencer module.
I would look closely at the wire and plug, to make sure they're not frayed or cracked. Be alert to odd smells, or a snap, crackle, pop sound that could indicate internal arcing. Other than that, though, it should work fine.
It takes an iron man to play with a toy iron horse.
One item to check is what kind of diodes are used. A power pack that old may contain a selenium rectifier bridge. If the bridge looks like metal plates stacked together with a rivet in the center then you have a selenium bridge. They have about a 30-40 year life used or unused. Also the fumes are not to good if they burn.
You'd likely be better off with a more modern power supply. I needed a steady AC source for my switch machines and settled on an old Bachmann trainset transformer. While it doesn't put out much power it's more than enough for the switch machines and is circuit breaker protected. I also use it as a power source for my Kadee Speedi-Driver Cleaner Brush. All my DCC locos are analog enabled so this makes it easier to clean the wheels.
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nedthomas One item to check is what kind of diodes are used. A power pack that old may contain a selenium rectifier bridge. If the bridge looks like metal plates stacked together with a rivet in the center then you have a selenium bridge. They have about a 30-40 year life used or unused. Also the fumes are not to good if they burn.
I'd pretty much bet the farm that a Scintilla Unipack will have a selenium plate rectifier in it. They're definitely that old.
Another thing to watch out for on old anything that plugs into the wall is the condition of the line cord and plug. If there is any cracking of the insulation - toss it back.
--Randy
Modeling the Reading Railroad in the 1950's
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I remember the Scintilla brand name from the 1960s. It definitely has a dry selenium rectifier stack. A hum from the transformer is normal, but as others have said, watch out for overheating, a bad smell, a frayed power cord, or any snapping or crackling noise from inside.
If you can get it open you'd be much safer by replacing the selenium rectifier with a new 5 or 10 Amp diode bridge.
jeffrey-wimberly You'd likely be better off with a more modern power supply. I needed a steady AC source for my switch machines and settled on an old Bachmann trainset transformer. While it doesn't put out much power it's more than enough for the switch machines and is circuit breaker protected. I also use it as a power source for my Kadee Speedi-Driver Cleaner Brush. All my DCC locos are analog enabled so this makes it easier to clean the wheels.
Actually, I have a trainset power pack from an old Model Power trainset which I tried to use. It works okay for a single switch machine. However, I wire my crossover turnouts so both get thrown with a single switch. The Model Power only puts out 6V from the accesory terminal as opposed to the more common 12V and that isn't enough to move two switch machines simultaneously. As long as this one doesn't show any signs of problems, it should be just what I need.