RE: The OLTC II lives!

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Steve Conner" <steve.conner-at-optosci-dot-com> 

 >BTW, how loud is that thing when it runs?  Is it very similar to a real
 >tesla coil???

 >I was
 >wondering about the noise from the IGBT switching as well.
 >Not just the dB level but the characteristics of the sound...
 >is it a staccato effect like a disruptive coil?  Or is it more like
 >a VTTC staccato circuit sound?  If you have the time and
 >equipment to record a .wav file it would be great!

I certainly can record some stuff. The noise from it is pretty surprising.
If the secondary is removed or breakout is suppressed, all you hear is the
sound from the primary circuit, which is a loud buzz or whine. This is down
to Lorentz forces making the conductors vibrate.

When the coil is sparking, the noise from the discharge drowns the primary
out completely. At the 500bps breakrate I have been running, this is a
deafening siren-like wail that echoes right down the street. It sounds just
like my DC resonant spark-gap coil because that's basically what it is :)

At very low breakrates, each individual shot can be heard. The primary gives
out a loud click, but again this is drowned out by the streamer discharge
which goes BANG! It's nothing like the plop! sound of a staccato VTTC.

Steve C.