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,
Cardboard sheets cut from a shoebox
Multicolored CCLs (8) – 10 cm x 0.4 cm; available thru
Rubber grommets (4) – available from Radio Shack (http://tinyurl.com/7ufs58b)
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 (https://www.instructables.com/id/Tesla-Night-Light/).
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.