Re: Pushing Neons (fwd)

---------- Forwarded message ----------
Date: Tue, 28 Jul 1998 21:06:01 -0600
From: terryf-at-verinet-dot-com
To: Tesla List <tesla-at-pupman-dot-com>
Subject: Re: Pushing Neons (fwd)

Hi Marco,
	There is resonance between the NST's output impedance and the primary caps.
The gap firing is used as a source of loss to break the resonance.  Normally
this resonance is much worse in a typical circuit.  I feel my circuit puts
far less strain on the neon.  However, the special case mentioned does take
the NST out of it's specifications momentarily which caused me some concern.
The primary seems to be tough enough that a short term overload will not do
any harm.  The secondary is much more fragile and I was concerned about the
unusual heating on the windings.  

	Terry Fritz

At 08:38 PM 7/27/98 -0600, you wrote:
>From: Marco Denicolai <marco-at-vistacom.fi>
>To: Tesla List <tesla-at-pupman-dot-com>
>Subject: Re: Pushing Neons (fwd)
>At 22:35 25/07/98 -0600, you wrote:
>>---------- Forwarded message ----------
>>Date: Sat, 25 Jul 1998 17:53:00 -0600
>>From: terryf-at-verinet-dot-com
>>To: tesla-at-pupman-dot-com
>>Subject: Pushing Neons
>>Hi All,
>>        I have been playing with a high performance charging circuit design
>>that uses a 15kV 60 mA neon transformer.  I have the design ironed out so
>>that when the input voltage is 120 volts, the current is about 8 amps.  The
>>output voltage is 15kV and the current is 60 mA (all RMS values).  This is
>>charging a 20nF cap to 21 kV peak.  So everything is within specifications
>>of the components.  
>>        The first problem is when the gap fails to fire or you are turning
>>up the variac and the gap hasn't fired yet.  Without the gap firing, the
>>neon's input current is 20 amps.  The output voltage is still 15kV but the
>>output current is 115mA. 
>Please, mind my stupid and simple question, but I don't really understand why
>if the gap doesn't fire the NST sinks higher current. Do you mean that if the
>gap doesn't fire you reach a point of the AC half-wave (charging the primary 
>capacitor) that results in 115 mA of charging current?
> Marco Denicolai                   Vista Communication Instruments, Inc.
> Hardware Development Manager      www.vistacom.fi   
> marco-at-vistacom.fi                 Kaisaniemenkatu 13 A
> fax:    +358-9-622-5610           SF-00100 HELSINKI
> phone:  +358-9-622-623-15         Finland
>   Remember, Murphy was an optimist! I am not...