Re: "Gas burner" corona from STSG driver

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

Original poster: "davep by way of Terry Fritz <twftesla-at-qwest-dot-net>" <davep-at-quik-dot-com>

Tesla list wrote:

> Original poster: "Lau, Gary by way of Terry Fritz
> <twftesla-at-qwest-dot-net>" <Gary.Lau-at-compaq-dot-com>

> Be careful how you state this.  The terminal voltage of a Tesla coil is AC.
> The secondary oscillations are centered about zero volts.

	Sort of.
	Since the voltage decays, any systematic asymmetry in wave form
	can lead to a 'net DC' (albeit 'small') at this point.
 
> Insulated objects near the secondary will develop a DC or static charge
> deposited upon them, due to the asymmetric conduction (a.k.a.
> rectification) of corona.  This is what an electroscope will indicate.

	Concur.  Older references (maybe even some web resources)
	will discuss Corona Rectifiers which were, in the past,
	used for production of HVDC.  cf also the archives of this
	list, where this has come up before, typically in the
	'shocks from depowered secondary' (form) discussion.

	There is a whole range between 'pure AC and pure DC'.

> Gary Lau
> MA, USA
 
> Original poster: "John H. Couture by way of Terry Fritz
> <twftesla-at-qwest-dot-net>" <couturejh-at-mgte-dot-com>
 
>> Tesla coils were used by hospitals to make X-Rays (DC
>> needed) until the thirties when other devices became available.

	X-Ray tubes work just dandy from an AC supply.  They ignore the
	the alternate polarity.

	If trying for a nonpulsed supply of XRays, one may wish
	to supply DC...  Typically pure DC allows better control
	and more intense beam.

	best
	dwp