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Wiring a Bubble Machine Answered


I have a bubble making machine which recently had to have the capacitor and transformer replaced.

However, I cannot get the machine to run the fan when its all connected. I think the wiring is all a bit of a mess, and I am wondering if someone can help me find a solution to get it to operate again.

At the moment when the blades in the diagram are connected to the 3 pin switch only the motor which rotates the wheel for the bubble machine operates, the fan does not work. I have tried others (I have assumed these work but I don't know how to test them independently) but no success.

I am unsure if the capacitor is wired correctly either, as reading about it online I have found that one pin is negative and the other is positive :(

Also, I swapped the old transformer (see attached) for a replacement led transformer for running 12 volt light, I don't know if this was a suitable replacement.

Please help me!!


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Best Answer 2 years ago

If I interpret the drawing correctly then you might have blown something already.
Great job providing the details here !
Here is what should have been connected to what:
Try it like this;
Mains power (live) to the switch.
Mains power neutral connects to neutral on the transformer and motor.
From the switch you take the switched mains power and connect it to the transformer and motor live connections.
Like this the switch will then turn on the motor and transformer.
The output from the transformer goes to a rectifier you need to add.
Means the 12V output of the transformer connects to the AC input of the rectifier - polarity here does not matter.
Output of the rectifier as labeled on the casing goes tot he fan motor AND capacitor - poistive to positive and negative to negative of course.

If the fan did not blow up during your first attempt(s) then it shall work now.
In case it does not: please check if actually 12V is coming out of the transformer!
As it provides AC it should not need a big load connected to it but some of these LED transformers simple switch off if you start them without a load.
You can also just connect the AC side of the transformer to mains power and measure with a multimeter if 12 AC is coming out, might be a bit higher without a load, so maybe 18V.
No output at all: Try adding a 12V / 10W light bulb to the transformer output.
If the light goes on when you connect mains power then you might need to keep the light as a ballst for the transformer to operate.
Could double as a nice spot light for the bulles as well.


Answer 1 year ago


Thanks for your advice, it helped me to simplify the cabling.

I managed to source a 240v to 12v dc transformer (power convertor) for led. That operates the fan okay. I'm not sure if it has a capacitor or rectifier built in but it operates the fan so im happy.

Thank you !!!

Jack A Lopez
Jack A Lopez

2 years ago

I humbly suggest checking the voltage, on the wires going to the fan, using a multimeter, for to determine approximately how much voltage is on those wires, and also if it is AC or DC.

Regarding the power converter in your second picture, the box with two red wires and two white wires, the markings on that seem to suggest its output, which is on the two white wires, is 12 volts AC. Guessing the red wires want to be connected to (L)ine and (N)eutral of your mains power, at 220 VAC, as input.

If the voltage going to your fan is AC, and the fan wants DC, I think that might be plausible explanation for why it is not working.

By the way, in the old usage of the word, a "transformer",


is necessarily a power converter with AC input, and AC output.

Although, in the new sense of the word, especially used by laypersons with superficial understanding of electricity, a "transformer" is any kind of electric power converter, so the output could be DC, could be AC, or whatever. It is like these people use the word, "transformer" interchangeably with "DC adapter", or "AC adapter", or "power supply", or "DC-to-DC converter", etc.

I dunno. If in doubt, I just call it a power converter, because that's truthful language, if general.

Regarding the capacitor, if there are markings on it suggesting polarity, like one terminal labeled with a plus (+) sign, that usually means it is a, what they call, polarized capacitor. That kind of capacitor should only be connected to DC, and only with the matching polarity.

Also regarding the capacitor, some types of AC motor need a capacitor (always a non-polarized one, since it is used with AC) to run properly.


In contrast, DC motors usually do not need a capacitor to run properly. So I am not sure why the DC fan in your bubble machine has to have a capacitor attached to it.

Although your DC motor probably does want some DC voltage, and that was my main worry, which is why I suggested you check that first.

If your DC fan is the same kind as found in desktop computers, and I think it is likely that it might be, since those kind of fans are cheap and ubiquitous, then it will run comfortably on any DC voltage, roughly in the range from 3 to 12 volts, and the magnitude of the voltage determines how fast it runs.