AC/AC Adaptor suppliers

You sure its not 12v DC?

-- Sir Benjamin Middlethwaite

electrical

adaptor:

It's only a transformer 240v in and 12v out at 1.8 amps. Maplin sell part WB25C for £9.99 that fits the bill, but you would have to mount it in something to make it safe. According to their web site they have

AWEM

Ho its a jap thing

Right then - time to dig out my electronics and soldering books!

Thanks for the advice, Durn.

If it really is AC/AC....then look at garden lighting transformers. I see a 60W (5000mA) one here for 11.39 plus VAT.

Low voltage (halogen) lighting transformer? Not sure if your (dad's) lights are really going to be fussed whether it's really AC: it may just be that they don't mind that it's not DC so there was no point spending extra on rectifying and smoothing the output on the original unit.

However if there's a rectifier and electronics inside the light set then it might not like the high frequency output of electronic 'transformers'. A suitably-rated (12 * 1830 ~= 20W) copper + iron transformer (e.g. out of a cheapy 5 quid LV lamp) should do.

IOf it's like mine. Then AC is needed - thjere is a little AC motor inside to turn the colourwheel, to make it change colours.

Really - a 12V AC motor?

I'm not doubting that such a thing is possible, just wondering about the economies of scale: if I were designing a rock-bottom-price consumer gizmo I'd expect to find that an off-the-shelf 12V dc motor (made by the zillion) plus a diode, would be cheaper than a 12V ac motor which must be quite a rare beast.

Small synchronous motors are common on things like washing machine programmers, etc. DC motors tend to run too fast.

Yes but they're mains not 12V. I agree it could be 12V AC and what you say about the speed is a point, but it would surely be more expensive than either a 12 DC or 240V AC motor because it would have to be made specially for this product.

Could be. Small slow motors for things like colour wheels are fairly common on fibre optic decorative lamps etc. Anyone had one apart to see what it is?

Me. My little tree has a 5V 1A lamp (with integrated reflector) pointed into the ~3cm fiber bundle that comes from the branches from some 1cm away.

Between the end of the fiber bundle and the light is a colourwheel run from a standard slow speed AC motor, like is used in microwaves et al, running at maybe 5RPM.

I took it apart after 5VDC failed to rotate it.

IIRC, it was 10 quid all-in.

So did 5V AC do the trick?

Presumably these are synchron(ous) motors similar working on the same principle as those in motorised valves, electric time switches and old-fashioned CH timers (and very old mains electric clocks).

Yes.

Yes. (for others) These things are typically a pancake, 60mm in diamter, 20mm thick, with a takeoff shaft 10mm off-center. There is inside a little circular magnet, between the poles of an electromagnet in the bottom 'half', and the upper half is a gearbox reducing to whatever speed, typically in the range 0.1-60RPM. Low single digit, or fractional watts consumption, and found in everthing from washing machine timers to clocks, to ...

replying to Durn, 12vac wrote: Here's the part you need - 12V AC/AC, perfect for powering your fibre optic Christmas tree:

He has probably thrown away the Christmas tree since he asked the question 12 years ago.

Please see

Might still be in his loft!

I had a situation a few years ago where my colleagues had lost the PSU for the fibre optic Christmas tree. It did indeed require AC to make the motor turn (I found an old fashioned AC / DC wall wart and bypassed the rectifier regulator and capacitor.