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Re: Pole pigs -- costs



Tesla List wrote:
> 
> >From jim.fosse-at-bdt-dot-comSat Aug 31 10:38:03 1996
> Date: Sat, 31 Aug 1996 07:40:56 GMT
> From: Jim Fosse <jim.fosse-at-bdt-dot-com>
> To: tesla-at-pupman-dot-com
> Subject: Re: Pole pigs -- costs
> 
> >From: WILLIAM HENDERSON <hb-at-earthlink-dot-net>
> >To: tesla-at-pupman-dot-com
> >Subject: Re: Pole pigs -- costs
> >
> 
> >> With a pole pig, you need the following items that you don't need for
> >> neon based systems: (Your prices may vary)
> >>
> >> A pole pig ------------------- $300
> $60 only 7200V though.
> >> 50A/220V worth of variacs ---- $200
> not yet;(
> >> Arc welder ------------------- $200 (new)
> $15 wire to build inductive ballast - 9mH
> >> Oven elements ---------------- Free (salvaged at recycling center)
> $15 each.
> >> Wire for power cabinet, etc. - $100
> free - scrounged
> >> Power cabinet (contactors,
> >> circuit breakers, wire,
> >> meters, etc, no variacs) ----- $150 (est.)
> >>
> >> Rotary gap
> >> (materials: G10, Plexiglas,
> >> polycarbonate, shaft,
> >> bearings, nuts, bolts, motor - $180 (est.)
> >> --------------------------------------------
> >> Total:                         $1130
> So that is where my budget went;)
> 
> you also forgot the replacement cost of home electronics due to home
> build ballast testing ~$65 so far.
> >>
> >> There are probably some items you can do without, but if you have kids,
> >> you will want a cabinet to enclose the dangerous/delicate stuff, and
> >> with resistive load, the performance is not as great (I hear).
> Caveats for resistive ballast: 220V into a 110V tap of a 7200V pig
> with ~5ohms resistive ballast. Makes a GREAT light show! I have
> achieved complete 360 degree power arcs, they're quite spectacular.
> 
> >>
> >> Basically don't expect to plunk $300 down for a pig, take it home and plug
> >> it in.
> Just for grins, I DID. My poor rotary could not quench it's arc,
> before the circuit breaker blew. I as sorry to report that I was not
> watching the mains current meter at that time;(
> >>
> >> Flames are always "welcome".
> >>
> >> Chip, the cheapest way is to build yourself  reactor's, this will get
> >rid of the variac's, arc welder and oven elements- my reactors all have
> >taps coming out for different current settings,this will also get the
> >juices flowing,it's the trade off, thought for bucks,my 18,000 watt t.c.
> >can't tell the diff.
> >
> >[Reactors?  Could you elaborate?  -- Chip]
> >
> William,
>         I would love to hear the details of you inductive ballast.
> I've wound a small (9mH) iron core inductor to ballast my pig with.
> Without a resistive  shunt across it, I take out
> unhardened-home-electronics from it's flyback effect when the gap
> quenches. This is through the (parallel) 23uF capacitance and 2
> series) RFI filters I have between it and my house wiring.
> 
>         jimChip and Jim,
             A reactor is a device that controls the inductive reactance of a 
circuit,the principal property of an inductance is to resist any change in 
current through it,and therefore any inductance in a circuit will impede the 
flow of alternating current.Your arc welder is a reactor,limiting the 
short-circuit-current to your transformer.The ideal way(cheapest)to control 
the reactance is the saturable-core reactor,this consists of a magnetic core 
with D-C and A-C windings,dc controls the inductive reactance of the ac 
winding,more dc=less ind.reactance and vice versa.The ac and dc winding can 
not share the same core,the flux linked with the dc winding can't be affected 
by the ac current in the ac winding.I'm not up on the drawing method used 
here on the net,so if you can visualize a figure 8  the dc winding goes 
around the center bar ,the ac winding goes around the top bar exits on the 
right goes down to the bottom bar enters on the right and exits on the 
left,the windings need to be wound in phase(same direction).Using a figure 
eight core with the two ac coils, produce flux in opposite directions through 
the central core on which the dc winding is wound.Therefore,the currents in 
the ac windings neutralize each other with respect to the production of flux 
linking with the dc winding,the iron core losses it's inductive effect when 
dc is applied to the center core.The other type of reactor i use has taps 
coming out every row,here are the dimensions 18"x 6" X 1", soft steel will 
do, laminated would be better,leave an inch at each end wind approx. 500 
turns of stranded 10awg. wire.Each tap is brought out 3",windings should be 
neat and tight,before winding paint and deburr,wrap with fish paper and away 
you go,this sucker is very heavy and will get hot!.With this setup i can 
limit current flow between 45 amps(no taps engaged)to system melt down,and 
yes i've blown the mains a few times,amprobe has read 200+ amps a few times.
well good luck   P.S.-----I think everything came in under $50
                                                     Bill   hb-at-earthlink-dot-net