Free Web Hosting Provider - Web Hosting - E-commerce - High Speed Internet - Free Web Page
Search the Web

Our Baby Coil.

• Power: 9000vac @ 30ma Neon Sign Transformer. 270 VA
• Capacitors: 4 wine bottle salt water caps
• Spark Gap: This uses a neat, 3-stage adjustable gap. Each gap is formed between the flat head of a 1.25" steel bolt and a flat plate of steel. Each bolt cab be threaded closer or further away, making the gap good for any voltage under 12KV. It perfromed as well as the RQ gap in the BBC. Orinally 5 gaps, accross the heads of a series of roofing nails in a piece of wood. Later it was a series of 3 gaps made from steel L-braces.
• Primary: Originally was 10 turns of insulated, stranded speaker cable. A pin was pushed through the insulation to make the tap. Then was steel wire wrapped around a cardboard form (Quaker Oats can) 13 turns total, tapped at 6th turn. Now is Bare copper 12 gauge wire, wrapped around a 5" form, 12 turns total
• Secondary:2.25"X11" PVC. Winding length is 10" 24 gauge magnet wire

  

• Terminal: 4" cast aluminum sphere (self-made!). Originally, as shown in some of the images, we used one of the balls from a softball batting cage, covered with aluminum tape. (you can see the dimples in some of the photos)

  

• Arc Length: ~6"

some other pictures of the baby coil in operation... ...though not any better :(

Dreams for the baby coil's future:

A .009uf 30,000vdc polyethylene dialectric capacitor(sigh...) An RQ-style cylindrical static gap... A coil such as this one has much room for improvement, with the capacitors having the poor qualities of a glass dialectric, the spark gap being unreliable and poor in quenching capabilities, and the primary conductor (steel) heats up since it isn't conductive enough. (well, fixed that one now)Copper should be used instead. Better capacitors could be purchased or made, with fine results. A Richard Quick cylindrical static gap could also be constructed. All these improvements could and should be made if you are looking to construct a professional, well-performing coil, but if you don't feel like spending the extra time before you get to create miniature lightning, then go ahead and do the sloppy, bargain-basement, super-scrounged type coil. It will still work :). This was the first coil we (kinda) built together, but I had built several coils beforehand, though none of them were as powerful as this one. They were just to prove to myself that I could build small tesla coils inexpensively. Actually,My first coil was built in a single evening, after coming home from the library(they had internet access) where I found out how to build salt water capacitors. It used a single cap, with a single gap, a secondary made from 22 gauge telephone wire wrapped around a cardboard tube, a flat spiral primary stapled to a wooden table, and an old television (HV taken directly off of the flyback transformer) as its power supply. It produced an arc merely an inch long, but I even got video (first coil ever!) of it!

The secondary of the baby coil was wrapped with the form locked into a metal lathe(courtesy our metals shop teacher), but for better control we put the clutch in and spun the chuck by hand, feeding the wire on with gloves.

"what would happen if you touched that?"-> a question commonly asked
by other students in my metals class

email: electophile@juno.com

Back to the Main Page