Running without secondary

From:  D.C. Cox [SMTP:DR.RESONANCE-at-next-wave-dot-net]
Sent:  Friday, June 19, 1998 6:42 AM
To:  Tesla List
Subject:  Re: Running without secondary

to: Gary

It could be lethal to your capacitor.  Without a load the Q rises
considerably and the power has no where to go.  Imagine putting a manual
car transmission in neutral -- now put the accelerator pedal to the floor
-- with no load it could damage or seriously strain the engine.  Running
without a cap is equivalent to this mechanical process.


> From:  Gary Lau  18-Jun-1998 0758 [SMTP:lau-at-hdecad.ENET.dec-dot-com]
> Sent:  Thursday, June 18, 1998 7:28 AM
> To:  tesla-at-pupman-dot-com
> Subject:  Running without secondary
> >   Before you try your idea, I thought you should be warned that it is
> >advisable to run your system in the manner you described.  I have not
> >this, but many on the list have said that this is a good way to kill
> >power supply.  Apparently, there is no way to dissapate the energy if
you run
> >without the secondary and it will feed back to your transformer and burn
> >out.  
> I have heard this advice given many times but I have not heard an
> explanation that really explains why.  While on the surface, I could see
> that if the energy is not going into the top terminal discharge, it must
> be going somewhere else.  But is it not possible that rather than
> quenching after transfering the energy to the secondary, the primary may
> just ring for an extended period of time?  The energy would be dissipated
> in the longer gap conduction period, plus the cap, if not using low-loss
> dielectric, would generate more heat due to the longer ringdown, plus
> skin effect and other resistive losses, plus radiated EM fields.  The
> first portion of the ringdown after the gap first conducts will look
> identical, regardless of whether there is or is not a secondary, and the
> voltages and currents only go down hill from there.  There is no "kick
> back".
> Could it be that the longer ringdown presents the power supply with a
> higher duty cycle of high frequency bias, and that it's the extended duty
> cycle, not a difference in magnitude, that makes this bad?
> Gary Lau
> Waltham, MA USA