Introduction: Wireless Rainbow Light Powered by Tesla Coil

Here is a project that uses radio frequency energy generated by a small, bipolar Tesla Coil to energize a ring of multicolored, cold cathode lamps. As with any high voltage device, use caution and good judgment when operating.

Step 1: Parts & Tools

Bipolar TC (1) – purchased, scratch built or modified,

monopolar unit

Cardboard sheets cut from a shoebox

Multicolored CCLs (8) – 10 cm x 0.4 cm; available thru

hobby shops

Rubber grommets (4) – available from Radio Shack.

Utility scissors

Office hole puncher



Step 2: Tesla Coil Fabrication

     I opted for a scratch built TC. Except for the following modifications, the design was nearly identical to the monopolar version that I described in a previously published i'ble (

I mounted the secondary horizontally, disconnected it from ground and then capped the ends with aluminum discharge globes bolted to ceramic insulators. Lastly, I used a concentrically coupled coil to replace the pancake primary. Once the TC was completed, the remaining construction was intuitive.

Step 3: Lamp Support Construction

     Scrap cardboard from a shoebox served as supports to secure the ring of lamps around the primary coil form. I cut two, 5 cm diameter circles with center holes having the same size as the secondary coil form. Next, I made a radial cut to the center hole of each support so they could slip over the ends of the secondary.

Step 4: Punch Holes and Insert Lamps

I used the paper punch to make eight equidistant holes about 0.5 cm in from the edge of each circle. After placing the supports on the secondary and aligning the holes, I inserted 8 colored lamps.

Step 5: Final Assembly

     Finally, I cut four grommets in half and slipped one over each lamp tip.

Step 6: Final Adjustments

     After powering up the TC, I adjusted the variac and spark gap to produce a flickering display of rainbow colors. Here is a vid of a monopolar version of the rainbow light:
Make It Glow Challenge

Participated in the
Make It Glow Challenge