Tesla coil in a briefcase. This is my latest easily portable mini coil which gives 2-3 inch sparks. These are great fun and are generally safe due to the low power.
For more details with 10 photos and a video:
They are still impressive as you can get close to them and interact with them. This one is mains powered but setup is in seconds – open the briefcase, drop the secondary coil in place and turn on.
It was designed as a replacement for my original “mini” coil with a number of improvements, particularly in power, weight and portability.
It fits snugly into a briefcase with secondary coil lifting out and slotting into a space. Not sure what Homeland Security would say if you tried to take it on an aeroplane, though.
Briefcase Tesla coil internals with neon sign transformer at rear, copper pipe static spark gap at left, blue capacitors centre and mains suppression circuit at rear.
It runs from a 4 kV 24 mA NST (neon sign transformer) with a double spark gap made from copper pipe. The sparks from this are green through the green tinted acrylic. The tank capacitors are 1000 pF 30 kV ceramics. These are connected as a three strings of two (hence total is 1500 pF at 60 kV) and do get warm in operation. The primary is 10 turns and secondary 300 turns on a 3 inch former. Sparks are up to 3 inches. Ground is to the metal chassis which is also connected to mains ground. There is a mains interference filter (ex microwave oven), LED indicator and switch which is simple and compact.
Some stunts possible due to the low power.
A light globe and a small neon tube give nice effects as well.
Some slow motion effects
How about CD burning, above? The spark eats away at the foil layer until it is mostly gone. This takes up to 5 minutes.
Girls in red get a kick out of it too… (Tesla Forum Dinner 2009)
Runs at 869 kHz and shows the typical ringdown of a Tesla coil spark.
Related pages
Try something else
Laser Hand Effects
External links
A nice copy of the briefcase coil.
Photo Date: May 30, 2009, July 19, 2009