Thread: Electrical question

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I am trying to make a custom length of lights for a pumpkin light frame I have. I need 11 small christmas bulbs to be powered by 120 volts. I already tested it and they blew out instantly. How should I do this. A huge resistor? Run a 100w bulb in series with them?

That doesn't make sense. When you hack a flickering Christmas light string there's no resisters or anything. Are you sure those bulbs are rated for 120 volt and not 12 volt or something else?

No flickering bulbs. I have a pumpkin like this one.

I want to be able to light up the mouth independently from the rest of the pumpkin. I will be plugging it into a 120v ac controller so I can make it look like it is talking. There are 11 lights in the mouth and if you add 120v directly to them they blow out instantly and I want to figure out how I can keep them from blowing out.

each bulb is only rated for like 2.5 to 3.5 volts if these are the same type of bulbs used in christmas lights. The light bulbs themselves shouldn't care if they are getting AC or DC so you are looking for about a 24-33 VDC power supply. The only thing I can think of off the top of my head is a wall wart found at home centers for use in irrigation options. They usually operate from 24-28 volts and should feed the power that you need.

The problem is that if each bulb is only rated for 3 volts, and there are 11 of them that means that string is rated to "consume" 33 volts. When you put the full 120 VAC on that individual string you are applying WAY too much voltage to each bulb...effectively making each one drop about 11 volts vice the 3 each is rated for. That would be like taking your normal 20 pound luggage bag and adding a 60 pound bag of concrete to it and then expecting you to carry it just the same.

Hope this helped.

dK