Making The Stand
Bend a square piece of steel on both sides (90 degrees) about 2-3cm down. Mark the placement of the components and drill holes for mounting them...
Making The Relay
A good enough relay for this design is hard to find, so I will make instructions on how to make one:
-You will need:
-Tungsten rod, around 3mm diameter
- Coil form
- Enamel wire 0,25mm diameter, around 400-500g.
- Magnetic core (Any ferromagnetic material, it needs to fit snugly in the coil form)
- A flexible piece of metal for the moving relay contact
- Various mounting parts
- A schematic (This is a photo from a local magasine, it shows how to make a suitable relay for a Ignition coil tester...)
The coil needs to be wound with around 4500 turns of 0,25mm diameter enamel wire. If you decide on using this design, you should feed the power to this circuit full wave rectified, without a filter cap, and because the relay has such a large inductance, it will limit the current, so the ballast could be removed from the design...
Making The Primary
If you don't have a finished primary coil at hand, you can always make one. You Need:
- 4x PP (polypropylene, 1cm diameter, 4cm long) tubes
-1,5mm thick enamel copper wire.
- A power drill
You need to drill 2 holes through each of the tubes, each spaced 4-5mm from the next. then, you need to mount them to form a square on the stand, if one edge of the square is 10cm.
Then, here comes the hard part... You need to get the wire inside the holes, carefully creating a helical figure, when you get past that, you are finished with the primary coil!
Making The Secondary
Making the secondary is pretty straightforward, you need to get a cardboard or PVC pipe with 50-60mm diameter. (PP works best here, but it's more expensive...) Then you need around 150g of 0,17mm enamel copper wire. (Where I live, the guy that rewinds old motors and transformers, sells us the wire in grams) Then, here comes the long part:
-Turn on the TV
-Watch your favorite show
-Start winding and wind until the coil is around 270mm long
-When you finish, fix the ends, and coat the wire with varnish. When it is dry, you can use it...
Connecting It All Together
Place the components, be sure to use proper insulation between the screws, components and stand. When you mount them, use the schematic (the second picture) to connect them in proper order, make sure that the only thing that has an electrical contact with the stand is the bottom end of the secondary coil. If you want, you can add terminals, one connected to the stand, and two for input power.
Great sparks for power input, high voltage magnification and low power consumption. Overall, great demonstration piece!