Re: Safety gap - setting

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Mddeming@xxxxxxx 



In a message dated 12/4/06 9:34:40 A.M. Eastern Standard Time, 
tesla@xxxxxxxxxx writes:
>Original poster: otmaskin5@xxxxxxx
>I just finished rebuilding & resetting my safety gap, but I'm not
>sure I got it right.  Basically I set the gap so it just barely
>wouldn't fire at full 130v variac setting.  I tested the setting by
>dialing the variac from 0v to 130v pretty much the way I would do it
>if I were actually starting up the tesla coil.
>
>My question is this.  When I already had the variac set at 130v &
>then hit the "on" switch, the safety gap would fire.  This abrupt
>powering up would fire the gap at settings that would not fire when
>I gradually dialed up the voltage to max.  To get the gap so it
>wouldn't fire when I powered it up abruptly, it required a much 
wider setting.
>
>Which of the 2 methods to test gap setting is correct - abrupt full
>power or gradual dial up?  Thx for any suggestions.  Dennis Hopkinton MA
>
>

Hi Dennis,

    The abrupt, full-power start is analogous to revving up the 
engine and "popping the clutch"  -you will get a lot more 
"squealing".  It does not promote equipment longevity, which is 
important to some folks. Full-power on creates major transients which 
your safety gap is designed to help divert. If your safety is firing 
before your main gap, or firing frequently, then one or the other is 
misadjusted. In general, the SUM of all the spaces in your main gap 
should be less than the SUM of the two spaces in your safety gap.
    IMO, the only coils that should be operated in the 
full-power-start mode are:
1) Very low power coils
2) Those that are massively over-designed.
3) Those that, like dragsters, have corporate sponsors.

Hope this helps,
Matt D.