Re: ignition coil based jacob's ladder...some questions

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: G Hunter <dogbrain_39560@xxxxxxxxx>

Hi Thomas,

Your dimmer may be overheating and saving itself from
destruction by shutting down. I'm only speculating
though.  I don't know that much about UK dimmers.  US
600W cheapo lamp dimmers from Wal Mart are "stupid"
and contain no protective circuitry.  Of course, at $5
a pop, so what if it smokes?

I think the first thing I'd try is a smaller series
cap.  Maybe 20uF is too big for it.  I'd also lose the
bulb ballast.

With a 2uF motor run cap, I once used this circuit as
an electric fence charger.  It ran 24/7 with no load
except for zapping the unwelcome bunny once in awhile.

Firing a spark gap or lighting up a plasma globe, I
never worried about duty cycle.  I'd run it for
minutes at a time and turn it off when I grew bored
with it.  I suspect it could've run indefinitely
however.  The little 2uF cap just didn't draw enough
current to stress anything.

Cheers,

Greg


--- Tesla list <tesla@xxxxxxxxxx> wrote:

> Original poster: "Ryckmans, Thomas"
> <Thomas.Ryckmans@xxxxxxxxxx>
>
> Folks,
>
> I would appreciate your comments on this...
>
>
http://hot-streamer.com/temp/IgnitionCoil-BasedJacobsLadder.gif
>
> I've build a simple jacob's ladder using Greg
> Hunter's
> (http://hot-streamer.com/greg) circuit (see gif
> attached) on 220V 50Hz
> with a 20 uF 440V capacitor and a 800W dimmer.
>
> I have added a 100W light bulb in parallel as a
> ballast (it seems that I
> burn through 5A fuses slightly less fast with this
> setting - is this
> because with this bulb the load becomes partly
> resistive rather than
> just inductive? ).
>
> The Jacob's ladder works fine - but there are a
> couple of things I don't
> understand:
>
>
> -after about 20 secs of operation, the lamp gets
> brighter (to 100% of
> power) and stays there - regardless of the setting
> of the dimmer (which
> minimum steeing is 75 W). As if the dimmer was
> completely conductive.
> Why is this? It comes back to "normal" after
> unplugging
>
> -I get sparks from the + AND the - primary plugs
> (but especially from +)
> to the secondary pin - it seems that these are about
> twice longer than
> the ones between the 2 narrow parts of the jacob's
> ladder. Why is that?
> Do I need thicker cables from the secondary to the
> ladder? I had to cap
> everything with glue from a hot glue gun (insulating
> tape leaked sparks
> and caught fire...) - this reduced the sparks
> somewhat. Any ideas about
> an insulation that is less messy? I'd rather not dip
> the whole thing in
> mineral oil - this thing is running on my kitchen
> table!
>
> -After about 30 sec the whole setup stops
> completely... then works again
> after unplugging and replugging.
>
> -My halogen lamp plugged to the same socket
> shorted... is this linked to
> the jacob's circuit running?
>
> I'd like to understand this and get a stable circuit
> before using the
> setup for a small desktop tesla coil
>
> Many thanks for your comments
>
> Thomas
>
>
>
>
>




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