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!
Did you get a 9 or 12 volt reading before you attached them to the terminal strip?
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:
Some AC transformers are marked in VA for volt-amps. At 12 volts, 25 VA would equal 2.08 amps.
Good Luck, Ed
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! [:D]
Frank
I new a guy with the same problem. It turned out he forgot to put the jumpers in his barrier strips.
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.
Well, wall warts won’t work when widgets within wear…whether worn, wet, wiggling, wonky.
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.
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.
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.
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?
That would be one reason to have an external fuse.
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.
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.
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
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
Some wall warts so not have transformers in them. They are switching supplies, and if they have no load, they have no output.
ROAR
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
Meters are highly over rated. [li] [li]
You guys and your over complicated electronics. Time to get back to basics.
