Synoptic Labs

My friend Rob’s birthday was coming up and a few of us got together to throw him a surprise party. Since Rob has been running a with a streak of high-voltage projects these past few months, what could be more appropriate than incorporating some extra volts into the surprise?

Solution: a high-voltage themed birthday cake with little Jacob’s ladders for candles.

A picture of the candle assembly before installation. The picture doesn’t show the arcs very well as they were a fair bit bigger than this picture suggests:

The candles were constructed by taking some lengths of laboratory glass tubing, stuffing them with wires and filling them with paraffin wax for insulation. The base for the cake was constructed in wood and trenches were routed out of it for the wiring to run through. These trenches were filled with wax as well and pieces of clay were used to help re-inforce the candles since I didn’t drill the holes exactly right the first time.

Æther took care of baking the cake and Kayobi helped with the design and the frosting. The candles were put into the cake by inverting the cake onto a wire rack and then carefully lowering the cake and the rack on top of the candles, so that the candles punched through the cake.

The candles were hooked up to a 15 kV neon sign transformer with a high-voltage capacitor placed in series to limit current flow. Without the capacitor, the arcs between the candles’ electrodes were so hot that they melted the wires. Had I any tungsten wire, I likely could have used that but alas I didn’t so I had to settle for wimpier arcs.

The surprise and ultimate presentation worked well however in retrospect I wish I hadn’t of used wood to stage the candles. The overall power and arc length of the candles was substantially less after I had mounted everything in the wood than it had been in earlier testing. I’m almost positive that some power was being lost through the wood somewhere even with the wax insulation on the wires. Acrylic would have been a much better material to use and I had completely forgotten that I actually had some hidden away at the time. Oh well.

This entry was posted on Wednesday, January 30th, 2008 at 10:57 pm and is filed under Tinkering, make. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.