Re: Summing up of Async Vs. Sync

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

Original poster: "Malcolm Watts by way of Terry Fritz <twftesla-at-qwest-dot-net>" <m.j.watts-at-massey.ac.nz>

Hi Jason,

On 21 Jun 01, at 18:27, Tesla list wrote:

> Original poster: "Jason Petrou by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <jasonp-at-btinternet-dot-com>
> 
> Hi List,
> 
> Right... from the numerous replies that I have got heres my impression of
> the uses of the two different types of gap:
> 
> Sync seems to be the most logical type of gap. (Assuming UK 50Hz) A 3000RPM
> motor with 2 contacts will give 100BPS, at the same time as the AC peaks,
> which is logical. This way the caps will discharge as the peaks occur, which
> is good, because it is the most efficient. It is also not going to allow the
> caps to overcharge, and is better for a (very delicate) NST.
> 
> Async gaps allow you to vary the BPS. Since caps will charge and discharge
> at the rate of the AC lne, then surely a Sync gap that is syncronised with
> the AC line is the best option. I do not see why you would want to vary the
> BPS when the charge rate of the caps can only occur at the AC line peaks and
> dips. Surely the most logical option is to discharge the caps when they
> peak, to get the maximum power through the primary, i.e. using a sync gap!!!
> 
> Really confused here
> Jason

Firstly, a word about rotary gaps: A rotary gap will fire any time 
its contacts are close enough to allow it to fire, *not necessarily 
or even usually _when the contacts are aligned_*. Async gaps can take 
advantage of this by allowing firings with a wide range of cap 
energies. The results all end up traversing a hot air channel 
beginning at the secondary terminal.
     A coil built for a gap with a low rep rate (read 120BPS for 
example) and for a specified power level (say 10kW) is going to have 
to process much larger primary bangs for that throughput than a gap 
running twice as fast or faster. That is going to have some influence 
on secondary design, and height in particular since primary energy is 
intimately related to output voltage. You could expect to have to 
build a taller secondary to handle the slower breakrate for a given 
throughput.

Regards,
Malcolm