Question on wall warts

If they show more than 5-6% out of range, they're not regulated.  My bet is they're also heavier than other similar rated walwarts, most likely a transformer and a rectifier is all that's in the brick.  The regulated ones are almost always switching power supplies and the coils are much lighter.

Thanks , trying to eliminate the use of buck converters around those 8 yr old hands. Are the wall worts that you find on Amazon the regulated ones?

tstark: Some of the Amazon listings for power supplies are regulated, and some aren't. Make sure you chose one that says that it's regulated.

@gunrunnerjohn posted:

If they show more than 5-6% out of range, they're not regulated.  My bet is they're also heavier than other similar rated walwarts, most likely a transformer and a rectifier is all that's in the brick.  The regulated ones are almost always switching power supplies and the coils are much lighter.

John, I ALWAYS respect and never challenge your expertise but I would like to ask something that's a shade different: If I test a wal-wart, say a 12V DC one as listed, and using a multi-meter is shows 12V DC does that really mean it's regulated? 

thanks John - walt

@walt rapp posted:

John, I ALWAYS respect and never challenge your expertise but I would like to ask something that's a shade different: If I test a wal-wart, say a 12V DC one as listed, and using a multi-meter is shows 12V DC does that really mean it's regulated?

thanks John - walt

That's about 95% sure.  To get to the other 5%, just put a load on it, say a 500 ohms across the output.  If the voltage remains very close to the same voltage, or drops a small fraction, say 11.9 volts, you've gone all the way, it's certainly regulated.  Also, you'll find universally (or almost anyway), that the regulated power supplies are much lighter.  In order to get the power capacity in the small package, they are using switching technology.  That means the coils are much smaller as they run at much higher frequencies so the wallwart will be much lighter.

I am a fan of Meanwell power supplies, and you can get a 12V 4 amp for about $10 on ebay.  It will take a bit of work on your part to provide a  power cord, maybe an on/off switch.   A 2 dollar extension cord, cut off the end with the receptacles, strip the wires and attach to 117 in.  If you don't use a main power switch to power all your transformers through a power strip,  you can either plug it in when it is time to play or get one of those attach to one side of the AC line in the cord switches. There is normally an internal line fuse soldered in place in the unit.  If you insist on a 3 wire cord for the safety ground, that will be a bit more involved, but securing the supply out of finger contact range, and it will be fine.  Walwarts do not use the safety ground because they are sealed in plastic, and there is no way short of a full meltdown, that the +/-  voltage on the output would get back to the AC mains.

There are usually efficiency ratings on the newer ones.  Look for a square box with a Roman numeral inside the box.  The number four (IV) and up are the better ones..  The Europeans I think drove the requirement for increased efficiency in these adapters.  The older analog ones also produced more heat as a by product of the lower efficiency.

As stated above if it's heavy then it will probably be unregulated and put off some noticeable warmth.