How do you make Christmas lights twinkle?

How do you make Christmas lights twinkle?

How can I make my lights twinkle (flash on and off)?

Short answer

Yes, just replace one of the bulbs in your Christmas light string with a red-tipped bulb and that section of circuit will flash on and off!

Long answer with photos

Good news, while it's not possible to modify a Christmas light string so that individual light bulbs randomly flash (or twinkle) on your string, you can flash the entire string of lights on and off using the red tipped flasher bulb that comes with many of the light strings sold at Christmas Light Source. (If your project requires randomly flashing bulbs, consider a set of chasing lights - see a video of a multi color set here.)

This is a set of purple craft lights. See the little plastic envelope? It contains replacement bulbs, a couple of extra fuses, and a red tipped flasher bulb. (Always save these little envelopes sorted by type of light string so they are always handy.)

A close view of the included mini lights accessories.

At Christmas Light Source (CLS) all the mini lights contain this accessory pack with a flasher bulb with the exception of our 15-bulb strings with 4-inch spacing. Craft lights with 20 and 35 lights to the string also have flasher bulbs

The following light strings at CLS do NOT have flasher bulbs: Craft lights with 10 or 15 lights to the string, battery lights (none of our battery lights sets have flasher bulbs), and our light strings that have 15 lights spaced 4 inches apart. (We are in the process of updating our light string specs to include whether they come with a red-tipped bulb or not. If you have a question about a specific light string, please contact us here.

Christmas lights with bulb accessory kit

Test the set of lights before beginning.

Unplug lights and carefully remove one of the bulbs. Pinch your nails around the base so the entire bulb and base come out and not just the glass bulb alone.

Here's the base of the red tipped bulb. Make sure those little copper wires are flat against the base. (They can be a little twisted.)

Install the flasher bulb. (This project was quick and easy, wasn't it?)

Plug the lights in and wait a few seconds for the flasher bulb to warm up and start to flash!

The red-tipped bulb heats up and then the flashing begins. Note that all the lights in the circuit where the red tipped bulb is installed will flash on and off. The bulbs will not randomly twinkle-flash.

Note that for a string of lights with 50 bulbs or less then usually the entire string will flash. For 100-bulbs strings made in more than a single circuit, the bulbs in the section of circuit with the red-tipped bulb will flash.

Does that make sense? If it doesn't, comment below.

As an alternative to the entire string flashing on and off, consider a string of chasing lights. A string of chasing lights can't be run end to end but they are constructed on 3 alternating circuits so they have a more random twinkle look. Here's a quick video showing the full range of flashing frequency.

So, did this help?

We hope so!!