110V AC to 12V AC converter

[Locoboy5150]

My girlfriend accidentally fried the 110V AC to 12V AC power supply that came with one of her light up Christmas houses. Is there any type of power supply that has an output of 12V AC and about 1 A? All the ones that I can find have 12V DC outputs.

I don't think that the house can use 12V DC because it has a small motorized color wheel that rotates inside of it that changes the colors of the fiber optic lighting system. I think that motor operates on 12V AC power only. Would I risk any damage to that small motor if I fed it 12V DC just to test it if it will operate on a commonly available 110V AC to 12V DC wall wart adapter?

The only other thing inside the house that uses power is a halogen projector type light bulb.

 

[Burgess]

Hmmm . . . .


Well, the Lionel train sets used AC power.

Perhaps an old Transformer ?


How difficult would it be to replace that pesky AC motor with a DC one ?

Just a thought.

:candle:
_

 

[carling]

Look for MR16 ballast/transformers. Most of them are designed to handle a minimum of 20 watts @ 12v. They come in AC or DC outputs so just double-check on that.

 

[Lynx_Arc]

if you are electronically inclined just get a 12v transformer at a parts store and wire it in a box with a plug and fuse etc. If shipping wasn't stiff I think I have a few 12vac transformers that are brand new but by the time they arrived the holiday would be over.

 

[kramer5150]

Hey did you ever solve this one?
Did HSC have a 12V AC transformer?

I think all this is just a step down transformer, in this case from 110 to 12. Usually transformers of this type have 2 output taps one at the spec'd Vout and another at 50%. Often times there is a label on the transformer somewhere to show which color coded coil tap is which.

I found these at an electronics part surplus store...

They step down from 110 to 20V, and are rated for 2.5A. In this case the coil has two Vin taps, one at the spec'd 110 and another at 220 for use in 220V countries.

Its just a step down transformer, all that crap on the side is just the fuse protection, coil tap switching and some a ferrite choke I added to cut noise and AC hum from the 110 input.

I use this to power an earmax vacuum tube amp, works great despite how scary it looks.


*edit*
I did a google search and found these... read the output specs very carefully. make sure they are AC output and have the current capacity to power your project.
http://www.bhphotovideo.com/c/produ..._Sound_TFP_008_TFP008_110VAC_12VAC_Power.html

http://www.mivs.com/products/powersupply/wp572412.htm

http://www.zzounds.com/item--STUSPPS

http://www.pegasusassociates.com/Elec60WPlugInTransformer.html

I have also seen people mod 12V DC units for 12V AC. They bypass/remove the rectifier circuit board, and just tap straight out of the 12V coil, but these are usually low current applications, less than 3-400 mah. Most wall wart 12V coils need to be low current simply because you can't safely hang the weight of a ~1A-12v coil from the AC wall outlet.

 

[kramer5150]

Hmmm . . . .


Well, the Lionel train sets used AC power.

Perhaps an old Transformer ?


How difficult would it be to replace that pesky AC motor with a DC one ?

Just a thought.

:candle:
_

I had an old Lionel train when I was a kid, with one of those blue / plastic transformers. I think they are nothing more than a small sized VariAC... variable AC transformer, where the output knob/lever just taps into different spots along the transformer coil.

example of a variac...
http://www.electroniccity.com/shopping/pricelist.asp?prid=1147

Loco, technically you can use one of these to solve your problem and set it to 12V output. But its most likely WAAAAY overkill for what you are doing.

 

[Locoboy5150]

Thanks for all your help guys!

Problem solved!

Here's what I did.

My girlfriend has a set of 6 ceramic Christmas houses, trees, and skating rink that all plug into one big 12V AC power supply. There are 6 sockets in the power supply that each unit plugs into. One of the trees had a short in it when the set was new and *poof* it melted the sixth socket when she first plugged it in. (The fireworks show gave her a heart attack too!) Thus, one of her units in the set has always never operated the past few Christmases.

I thought about buying a separate 12V AC power supply to power just one of the units, hence my starting this thread, but then (with her nervous blessing) I cracked open the power supply to see what was inside it. It was a really simple and cheap fix!

I went to Radio Shack and I bought an inline socket that was the same size as the 5 good ones left in the power supply. I soldered its wires in parallel with the other five sockets, drilled a hole in the side of the power supply plastic case for the wire to exit through, and voila - it has been working for a week!

Thanks again guys. All is well in my girlfriend's Christmas village. Now all I have to do is glue some of the windows of her village's church back in. They fell out a few years back.

There were a few figures and trees that were broken in the set too. Since I'm also into model railroading, I'm pretty handy with gluing small parts together, so I spent last Saturday working on that for her.

I'm sure that it's pretty obvious that my girlfriend never dated a guy that could fix anything before she met me!

Now that I showed her how well I could fix her Christmas village and bring it back into tip-top shape, she might have a whole closet full of broken things compiled over the past few years that need my attention. Oh no - what have I done?!!!

 

[Burgess]

Since I'm also into model railroading . . . .

I realized that fact as soon as i saw yer' UserName.


_