RE: [TCML] RSG speeds vs notches

["Lau, Gary" <Gary.Lau@xxxxxx>]

Hi Chris:

I don't believe that it's possible to achieve 1st notch quenching simply by speeding up the RSG RPM.  The actual electrode alignment time (i.e. speed) isn't terribly important, as gap conduction occurs prior to mechanical alignment, and continues well beyond alignment.  Quenching may be improved by adding a static gap in series with the RSG, though I'm not sure this is recommended with slower sync gaps, as it may cause misfires.  And gap losses are higher with added series gaps; I'm not sure any gain in quenching would offset the higher gap losses.

Your observation that higher RSG speeds result in poor performance is likely due to your cap not charging to as high a voltage, so your "bang" isn't as big.  The higher the break rate, the less time your transformer has to charge the cap.  What kind of transformer are you using?  If it's an NST, that will definitely be the case.

Regards, Gary Lau
MA, USA



> -----Original Message-----
> From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On
> Behalf Of Chris Swinson
> Sent: Tuesday, November 13, 2007 8:32 AM
> To: Tesla list
> Subject: [TCML] RSG speeds vs notches
>
> Hi all,
>
> with my RSG I used a vac motor and use it on a variac to change the speed.
> It works very well and gives a good range. However I imagine a higher speed
> would be useful in lowering the conduction time of the spark gap (always
> aiming for the first notch!) The motor will have to run fast with a large
> disc to manage it, though do not see any reason why it is not possible.
>
> The problem is as the gap is not in sync with the mains cycles, it is very
> hit and miss so higher speeds work very poor. As such , I wonder if I just
> use some microwave diodes and convert the NST output to DC. Its not really a
> DC coil, just thinking of charging the tank cap up and it holding its charge
> until the RSG fires, the diodes just preventing the tank from discharging.
>
> I suppose the other way is to just a sync cap though it will be in perfect
> sync with the mains, there is no way to alter break rates. The only way
> would be to build a variation of RSG disc making them larger and increases
> break rate speed.
>
> I am not really sure how to work it out. For example if the tank cap
> discharges in 100uS then the RSG needs to conduct for 100uS only. In this
> case it *should* be first notch quench.  However it seems nobody manages it
> ?
>
> It would seem 3rd or 4th notch is the normal, but why not build the RSG disc
> larger in dia to increase break rate speeds ? Or even place multiple
> electrodes across the disc so you can tap up or down the electrodes and
> alter the break rate ? I would have thought most people would build RSG in
> this way ?
>
> I understand that if the break rate is to fast the tank will not discharge
> fully. I also understand that if the break is to slow this is where the
> notches come into play as energy passes to and from primary to secondary
> reducing efficiency until eventually around the 4th notch the spark gap
> turns off.
>
> So either I am missing something or this type of gap is technically
> impossible to build in someway ? Maybe  a normal RSG disc would need to be 4
> times larger in dia to increase the break rate 4 times ?
>
> I suppose it is hard to work out the exact discharge time and the spark gap
> break rate times. It is why I wonder about building a disc with rows of
> contacts rather than just the normal 1 row. Then if you have several rows of
> contacts, you can adjust the break rate speeds by tapping up or down the
> rows.. the outer rows speed faster than the inner rows... Then I would
> imagine there would be a optimum row where spark output would be slightly
> better than the rows each side of that particular tap....
>
> Cheers,
> Chris
>
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