Operating an Induction Coil
If not already done, insert the pointer electrodes in the top pillars, set them apart to less than the coil specification, (e.g. 3 cm or so), and lightly tighten the top 2 thumbscrews. Connect a power supply (PSU) that meets the ratings specified for the coil (e.g. 6 - 12V @ 5A). There is a thumbscrew at one end of the base which moves a contact to and from the vibrator. This should be screwed out just enough to not contact the vibrator, then back in till it just touches.
Switch the coil on. If the vibrator doesn't move, move the thumbscrew out of contact and back in again. If it still doesn't, check that the PSU is properly connected and is powerful enough (the coil may draw a high current). If the vibrator works but there are no sparks at the top spark gap, turn the coil off and move the pointer electrodes in a bit. Spark length may depend on local conditions such as humidity.
If you're using it with other apparatus, e.g. Geissler or spectrum tubes, please start out with the PSU on the lowest voltage specified for the coil, to reduce the risk of burning them out. They will generally work quite well at the lower end of the induction coil's range.
If you wear medical electronics (e.g. a pacemaker) TAKE EXTRA CARE to avoid shock, especially any which may cross the chest, e.g. from one hand to another. Frankly you should have someone else (not in a similar circumstance) operate it for you. Otherwise the coil should normally be non-lethal, but can give a huge jolt if you're careless.
Jacob's Ladder
A staple of sci-fi films, easily constructed if you have 2 pieces of straight stiff wire (e.g. wire coathangers) of equal length, of several inches (e.g. up to say 12" each). Make a right-angle bend of about 2" at one end of each. Put them in place of the pointer electrodes, standing upright. Bend them apart a little so the distance between them increases from bottom to top. The distance at the bottom should be less than the maximum spark gap you have previously achieved. Switch on the coil and if there are no sparks switch off again, and move the electrodes in a bit.
