100pin Corona Loudspeaker
Having learnt a good few lessons from the earlier corona wind tests I came up with what I consider to be one of
my best small scale designs.
I wired a 10x10 grid of resistors on a 1cm pitch. When these
were pointed at a simple sheet of open mesh they created a really good wind generator, you could feel the air
from 2 metres away. But they barely produced any sound so I changed the grid for a matching array of
Left is a stereo pair of 100 pin corona wind
loudspeakers. They employ the grid of 10x10 (1cm pitch) resistors. The legs of the resistors
are clipped to be sharp and straight. They point at the ground grid that has pins soldered in a matching
grid facing them. Sorry about the bad picture - I've still got this and will try and rephoto it.
They are mounted in polystyrene packing material and the frames are nylon rod held togtether with hot
glue. Corona wind designs run cool which allows a wide range of materials to be used.
Below is the complete set up. 15kV power supply, a pair of 10kV single ended class A FET amplifiers and
the pair of corona wind loudspeaker elements. This produced a good clear sound, but still fairly quiet (below
speaking volume), with a fairly flat frequency response from the low hundreds hertz to above 25kHz. This set
up was a good demonstrator and could be powered up easily for most people to hear the principle working. The
cheap and nasty materials used do show through including chipboard, polystyene packaging, guttering and an old
plastic folder - but it shows that you don't need much budget to experiment with these things.