Re: HV & ballasts

["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: "Jim Lux by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<jimlux-at-earthlink-dot-net>
 
> So... Doing a bit of research on magnetic ballasts, it appears that there
> may be a huge supply of these...There's a federal law mandating replacement
> of old style ballasts... 


	Improved efficiency, some older may have PCBs.

 
> Anyone know what the internal circuitry looks like?


	Which Ones?
	They come in many styles, sizes, etc.
	The basic one Just An Inductor.

> I suspect they have a capacitor in them for PFC.


	I suspect not, mostly.  Never checked.  But.  The simple
	ballast is connected in series with the tube, so No Way
	to connect a PFC cap.  (If placed in parallel with
	inductor: defeats purpose of inductor....)

> How does the rapid start thing work (HV pulse to strike the

>tube...)


	The ones i used to sort of understand had a cap, to make
	a resonant circuit.  Once the tube struck, the load
	current shifted the inductance value enough to kill
	the resonance.  Or close to that.

	best
	dwp