One of my best clients lives on a secluded loop of a street well off the arterial. It's a fairly toney neighborhood, and there's a neighborhood association that coordinates Halloween festivities. Nothing fancy, just a preparation for trick or treaters who come in droves owing to the safe street and high income scene.

I help them with their Halloween prep every year, we get pretty elaborate. The house is on a slope, they put in a pond with a 20 feet creek flowing into it, recirculated by a pump of course. I get a bunch of dry ice pellets and throw them in the pond, which is right by the front walk. The kids all dig it.

Anyway, long prep, I feel a bit funny being the Halloween guy but oh well.

They have a number of stuffed figures, witches, etc, about a foot high, with LED eyes and buttons. They put these on the hearth of the outdoor fireplace, which is next to the front door. Very visible They all use the same type of transformer, which puts out 12 volts AC. Yes, no typo, !2 volts AC. The transformers all went bad, one at a time over the years, with one left, I wired all four of them to it and the extra load burnt it out. Anybody know if 12 volts DC would work? I have a battery in good shape, about as big as a car battery but it's deep cycle, used as backup for outdoor lights. I've searched, can't find a specific answer.

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1986 300SDL, 362K
1984 300D, 138K

Sounds like you need a 12 volt doorbell transformer. They come in 12 16 and 24 volts ac.
Don't know about that dc battery working.

I think you're onto something there. I bought a 16v AC doorbell transformer and it worked will. For awhile. I didn't watch it closely, my duties involved throwing dry ice pellets into the pond and faux waterfall/creek in their front yard next to the sidewalk. Jeez, I felt like a Halloween Wizard of Oz. Second year I've done the dry ice thing, had more this year, the kids dig it. Gives a witches brew look to the pond. When I put it at the top, the cold CO2 mist cascades down the creek-u-lets.

Anyway, at evening's end, I see the LEDs are no longer working. Perhaps the transformer is not meant for full time power draw. I mean, a doorbell uses a bit of current every once in a great while. Oh well, it was $13, if it's gone, no big. Hell, I spent $90 out of my own pocket on dry ice. Great fun. Here's the pond:

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1986 300SDL, 362K
1984 300D, 138K

DC will probably be fine, my only guess for them using AC was that a 120VAC->12VAC converter was cheaper than AC->DC?

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$60 OM617 Blank Exhaust Flanges
$110 OM606 Blank Exhaust Flanges
No merc at the moment

LEDs only work in one current direction. If all of them are wired in the same direction between the two poles, they'll work with the battery connected in one direction but not the other. If they're wired in DIFFERENT directions, then only half will work on the battery. (AC will cause them to flash on and off alternately faster than the eye can see.)

Over voltage as well with dc supply rated the same as the ac supply. The ac current should be measured to make sure a supply with enough current capacity is used. A strong 110 to 12V ac transformer might be cheap from ebay. Or a surplus electronic shop.

Do you have a picture of one of the ratings labels on one of the burned out transformers?

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-Evan


Benz Fleet:
1968 UNIMOG 404.114
1998 E300
2008 E63


Non-Benz Fleet:
1992 Aerostar
1993 MR2
2000 F250

The original may even have been some form of regulated supply. Instead though they may have got the load right for the original transformer to provider about the right voltage under load.