Primary coil is wound
from 5mm copper tubing held by an acrylic framework, A modified fuse holder allows
the tap to be varied.
So I had a 10Kv 40Ma NST lying
about.. I decided to build a bigger coil.
M y origonal sparkgap was an RQ gap with 5 gaps at 1mm. This didn't seem to give a very good quench, so the new Gap was constructed.
New Gap runs well, and I got given another 50ma NST so now running at around 1 KW with 2 NST's
New Config worked so well Ihad to change the top
load to a 8" sphere, but safety gap kept firing, Time to build a
2 x 8" frisbee's covered in aluminium tape
2 x 8" stainless steel mixing bowls from Ikea.
|The Spark gap is a linear RQ design, 10 individual gaps to around 0.5mm made from copper 12.5mn water pipe and 2 80mm fans to give an air flow around them for spark quenching.|
|The Capacitor is now an MMC made of 72 x 0.047uF Capacitors each rated at 1.5Kv giving a total capacitance of 24nf|
2 x 100t coils on 3/4" pvc water pipe, 4 x ferrite interference suppressors epoxied in side the tubes 2 in each. 4X 470 Ohm 10W resistors in series, with 4 x 100pf giving 50pf across each winding of the NST's
|Controller with keyswitch, "If the keys in my pocket its safe to approch the coil!!",|
The other two switches give me a 2 stage power input by separatly switching in the NST's
|Picture taken outside in a moderate breeze, shows nice banjo effect as ark is blown around, sparks are about 2.5' long.|
Streamers 2.5' long
Well they don't
have to be circular.
Topload appears to work. 2.5' arcs in windy conditions outside.