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Why Won't Wall Warts Work (alliteration!)?

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Why Won't Wall Warts Work (alliteration!)?
Posted by kasskaboose on Thursday, April 28, 2016 1:55 PM

I have new 9 and 12v wall worts and both don't work. I connect them to a terminal strip--one wire on an adjacent screw of a terminal strip for an HO layout.  Both wall warts won't function after plugging into electricty.  Ideas? I soldered tongue spades to the wires and that still didn't fix the issue.

Thanks! 

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Posted by slammin on Thursday, April 28, 2016 2:07 PM

Did you get a 9 or 12 volt reading before you attached them to the terminal strip? 

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Posted by gmpullman on Thursday, April 28, 2016 2:33 PM

What is the current rating marked on the wall-warts? I have some that are only 200 mA. that's only two-tenths of an amp. Are they AC or DC output? Does your load require AC or DC? Sometimes there is only a symbol like ~ for AC and === for DC (but the upper line would be solid). Sometimes a DC wall-wart has the + wire marked with a white tracer, but not always. You have to check with a meter.

Many wall-warts are in the 1 amp range, give-or-take, your load may be too great and the protection circuitry is shutting down. Some have a one-shot, internal fuse so if it is shorted or overloaded you have a plastic brick.

You have to know how big the load is and have a power supply that will supply that load and maybe 25 to 50% higher so you are not near the current limit.

I like to use a supply similar to these:

http://www.ebay.com/itm/DC-12V-5A-60W-Regulated-Switching-Power-Supply-Adapter-for-LED-Strip-Light-/321887363519?hash=item4af1fb61bf:g:3SEAAOSwNNxWEwA1

 

Some AC transformers are marked in VA for volt-amps. At 12 volts, 25 VA would equal 2.08 amps. 

Good Luck, Ed

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Posted by zstripe on Thursday, April 28, 2016 2:34 PM

kasskaboose
I connect them to a terminal strip--one wire on an adjacent screw of a terminal strip for an HO layout

What did You do with the other wire? Should have two. If You cut the plug off...center wire was + outside wire was -. When wired to terminal barrier strip, they should be side by side on one side of strip and jumpers from them to the other mounting screws on the same side.

https://www.youtube.com/watch?v=J-q3MOIXs_o

 

Take Care! Big Smile

Frank

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Posted by BATMAN on Thursday, April 28, 2016 4:20 PM

I new a guy with the same problem. It turned out he forgot to put the jumpers in his barrier strips.

Brent

"All of the world's problems are the result of the difference between how we think and how the world works."

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Posted by gregc on Thursday, April 28, 2016 5:09 PM

kasskaboose
Both wall warts won't function after plugging into electricty.  Ideas?

disconnect the wires from the barrier strip and verify the output with a meter.   Make sure you check for DC or AC depending on the output.

greg - Philadelphia & Reading / Reading

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Posted by peahrens on Friday, April 29, 2016 1:50 AM

Well, wall warts won't work when widgets within wear...whether worn, wet, wiggling, wonky.

Paul

Modeling HO with a transition era UP bent

Bis
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Posted by Bis on Friday, April 29, 2016 8:31 AM

I hate to change the subject, but what is meant by "wal wart" power supply.

Thanks ken

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Posted by maxman on Friday, April 29, 2016 9:28 AM

Bis

I hate to change the subject, but what is meant by "wal wart" power supply.

Thanks ken

 

It's one of those plug in the wall black things that provide power to many around the house electrical devices.  Our wireless home phone uses one to keep the batteries charged.

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Posted by MisterBeasley on Friday, April 29, 2016 9:33 AM

Sorry to be the bearer of bad news, but wall warts typically do not have circuit breakers.  Instead, they have one-time fuses inside to keep your house from burning down if you short them out.  Once you short out a wall wart for long enough, you have an ugly paperweight with an annoying wire hanging off one end.

Plug it in with no load and put a meter on the output.  If you see zero volts, you've probably fried the fuse and you'd might as well get another one.  Get a fuse holder and some external fuses, while you're at it, rated at 75-80% of the supply current.

Bis
I hate to change the subject, but what is meant by "wal wart" power supply.

A wall wart is one of those supplies that plugs directly into the wall.  Think about the charger for your phone or electric shaver.  They end up looking like a black wart growing from your electrical outlet.

It takes an iron man to play with a toy iron horse. 

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Posted by kasskaboose on Friday, April 29, 2016 11:36 AM

Given that the Wal Warts have no charge, how to prevent the fuse from getting fried?  I checked them for a current by having the wires touch each other.  The only place cheaply I see wall warts is online.   Any big box places?

Why would I need a fuse holder and external fuses? 

 

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Posted by BigDaddy on Friday, April 29, 2016 12:00 PM

kasskaboose
I checked them for a current by having the wires touch each other.

That would be one reason to have an external fuse.

Henry

COB Potomac & Northern

Shenandoah Valley

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Posted by maxman on Friday, April 29, 2016 12:06 PM

kasskaboose
I checked them for a current by having the wires touch each other.

I hope you don't check your house wiring that way.  You need a volt/ohm meter.  Touching the wires together just created a short.

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Posted by cuyama on Friday, April 29, 2016 1:06 PM

As others have said, the use of an inexpensive multimeter will keep you from frying more wall wart power supplies. Touching wires together creates a short that may have killed your wall warts instantly.

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Posted by richg1998 on Friday, April 29, 2016 3:29 PM

kasskaboose

Given that the Wal Warts have no charge, how to prevent the fuse from getting fried?  I checked them for a current by having the wires touch each other.  The only place cheaply I see wall warts is online.   Any big box places?

Why would I need a fuse holder and external fuses? 

 

 

Sigh. Even an auto light bulb in a proper socket with pigtails from Auto Zone would have been better. I learned that from old timer mechanics back in the 1950's.

http://www.trainelectronics.com/Meter_Workshop/index.htm

http://www.trainelectronics.com/Meter_HF/index.htm

These meters go for abour two to three dolllars. Might have different faces.

I have four scattered around the house. One in the car.

Rich

If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.

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Posted by richg1998 on Friday, April 29, 2016 3:34 PM

They don't measure AC current but have never found that to be an issue.

I have a one ohm, one percent tolerance high wattage resistor if I want to measure AC current using ohms law and the voltmeter option. Very rare though.

Rich

If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.

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Posted by BroadwayLion on Friday, April 29, 2016 3:54 PM

Some wall warts so not have transformers in them. They are switching supplies, and if they have no load, they have no output.

 

ROAR

The Route of the Broadway Lion The Largest Subway Layout in North Dakota.

Here there be cats.                                LIONS with CAMERAS

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Posted by SS Express on Sunday, May 1, 2016 9:02 AM

This was the first time for me hearing the term "wall wart". Pretty dang funny actually, but when I first read the thread title, I assumed it was a slam on Walmart......happy sunday.

Rich

Building the RDG, PRR, CNJ, LV railroads on the Huntington Valley Basement Lines.......
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Posted by Soo Line fan on Sunday, May 1, 2016 9:57 AM

Meters are highly over rated. Lightning Lightning

Jim

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Posted by BATMAN on Sunday, May 1, 2016 10:07 AM

You guys and your over complicated electronics. Time to get back to basics.

 

Brent

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Posted by maxman on Sunday, May 1, 2016 10:44 AM

BATMAN

You guys and your over complicated electronics. Time to get back to basics.

Good grief.  Another proponent of dead rail.  I have no intention of even considering dead rail until such time as they make lemons small enough to fit in the hood of my 44 ton loco.

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Posted by peahrens on Sunday, May 1, 2016 11:20 AM

BATMAN

You guys and your over complicated electronics. Time to get back to basics.

 

 

1.  Would this work if you hooked 3 Yugos together?  They would not spoil like the fruit.

2. If you switch those leads back and forth really fast you can get AC?

Paul

Modeling HO with a transition era UP bent

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Posted by BATMAN on Sunday, May 1, 2016 2:11 PM

 

For you guys that live in warmer climes, every time you come home with a couple of new loco's and need a booster, you can just go pick one off the tree on the porch.Laugh

Brent

"All of the world's problems are the result of the difference between how we think and how the world works."

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Posted by gmpullman on Sunday, May 1, 2016 3:52 PM

That kind of citrus abuse wouldn't be tolerated here in Ohio!

Stabbing poor lemons with zinc and copper bayonets Indifferent

We have LEMON LAWS to protect the innocent, little, rutaceaes.

http://www.ohioattorneygeneral.gov/Individuals-and-Families/Consumers/Consumer-Tips/Consumer-Tips-Auto/Lemon-Laws

All this talk of lemons is making me thirsty... time for a margarita Drinks

Ed

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Posted by rrinker on Monday, May 2, 2016 9:08 AM

 When life gives you lemons, make POWER.

                  --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by hobo9941 on Wednesday, May 4, 2016 9:32 PM

I checked them for a current by having the wires touch each other.

Both Walwarts are now dead. RIP!

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Posted by tomikawaTT on Saturday, May 14, 2016 6:11 AM

I resurrected a 'dead' wall wart (meant to charge 18V battery of a long-defunct power drill, 1.8A at 21VDC) by getting the guts and plumbing out of its shell.  After excising the bridge rectifier (I wanted AC) and discarding the fuse I mounted the transformer in a plastic project box, installed a 3-wire line cord with plug, provided it with an appropriate breaker (reset button easily accessible) and termini (#8 studs) and anchored it to the benchwork adjacent to the Nonomura control panel.  It operates twin-coil switch machines and a couple of relays, applications for which I needed enough voltage to work the devices with half-wave DC.  There are diodes in all the circuits, but no bridge rectifiers.

The most important thing to remember is to connect the line cord to the correct blades of the built-in 120VAC plug - including the ground connection.  You don't want to have a close encounter of the wrong kind with house current!

Chuck (Modeling Central Japan in September, 1964)

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Posted by gmpullman on Saturday, May 14, 2016 7:04 AM

Hi, Chuck

I have found relatively few wall-warts that can actually be pried open. If you do manage to get the shell off you are left with a large epoxy blob. It seems like so many electronic devices today are being dunked in some kind of epoxy or almost a tar-like substance. I recently had a $50. electronic ballast for a T-5 light fixture go dead. I wanted to poke around in there to see what went bad and after I got the housing open, all I was confronted with was a rectangular lump of green epoxy.

Rather than wall-warts, I like the power supplies that can be had for cheap from some of the Ebay sellers or All-Electronics.

http://www.ebay.com/itm/DC-12V-5A-60W-Regulated-Switching-Power-Supply-Adapter-for-LED-Strip-Light-/321887363519?hash=item4af1fb61bf:g:3SEAAOSwNNxWEwA1

Although I do use my share of wall-warts. I'm careful not to short them and I would say that out of the hundred or so that I have on hand I can remember only ONE being DOA.

Regards, Ed

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Posted by tomikawaTT on Sunday, May 15, 2016 1:55 PM

Howdy, Ed.

I 'pried' that wall wart open with a little judiciously-applied torque - on the handle of a bench vise.  Steel beats plastic every time.

The co-occupant of that little project box is a 12.6V 3A center-tapped filament transformer.  It carries the local light and panel indicator circuits.

There's still room in the box for a local control power pack for the two Down freight holding yards, which I'll need when switching the cassette dock.

I have a few other wall warts on hand, but none with a 20V - 24V output.  For lower voltages, give me a filament transformer every time.

Chuck (Modeling Central Japan in September, 1964 - with primitive, but bulletproof, electricals, all fully documented)

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