Currently i am using 1A ,9 and 12 volt, DC wallwarts to power my lighting, the bulbs are 12V. I have an opportunity to get some AC wallwarts at a great price. My question is will th AC do the job?
Doug
If they are light bulbs … yes.
If they are LEDs … no
Doug,
Phoebe Vet hit the point, but if you do want to use LED’s, just wire a Radio Shack 276-1146 bridge diode (good for 4 amps) to it and you’ll have DC. Then you can use it for LED’s (along with the appropriate resistor).
Lou
If you are using 12 volt bulbs, they will last longer and look better if you run them at 8 or 9 volts. I’ve standardized on 16-volt bulbs for my structure lights, and I run them at 12 volts.
These little bulbs run about 30 milliamps a piece. So, you can get about 30 of them on a 1-amp circuit before you get to the edge and have to worry about overloading the supply. It sounds like a lot, but you’ll reach that number and keep going. Most wall-warts don’t have circuit breakers, only simple one-time fuses to prevent a fire, but there’s no way to replace the fuses.
Just be aware of how many bulbs you’re using, and keep the number on any individual wall-wart down.
Last time I looked, LEDs were Light-Emitting DIODES. Those that only emit light with polarized input will simply operate half-wave on AC (and will still need the appropriate resistor.) Those which change color when input polarity is reversed will give some odd blended color, the sum of the two polarized outputs. In all cases, the reverse-polarity voltage must not exceed the diode’s blocking voltage.
As for incandescent lamps, they will operate on AC or DC of appropriate voltage without ill effect (although some will say that filtered DC will give longer life than either AC or un-filtered DC.) Running them at something less than their rated voltage will really increase their life - especially important if the lamp is installed in a building or scenic item.
Chuck (Modeling Central Japan in September, 1964)