[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

RE: saturable reactor vs choke

Original poster: "Jack King" <ekklekktikk@xxxxxxxxxxx>





From: "Tesla list" <tesla@xxxxxxxxxx>
To: tesla@xxxxxxxxxx
Subject: RE: saturable reactor vs choke
Date: Thu, 20 Apr 2006 18:02:42 -0600

Original poster: "Jim Mora" <jmora@xxxxxxxxxxx>

Hi Jack, all,

I will be running the water heater elements in parallel in a suitable water
filled container. Last time I tried this, the water came to a boil pronto.
Maybe a 30 gal plastic trash barrel will give  few minutes time for
metering.

My Lincoln Or my Miller could not send enough current to raise an arc to the
top of the Jacob's latter 3/8 6' x 18" top spead or so (welders buzzing like
crazy) bet you this big dude will :-)
My money is on you getting a teeny tiny liittle buzzing spark to start, then when you move into the knee, you should have some nice fat fire.... 


I have a dual 1256d so I can

control
the voltage too if needed.

Please do keep me in mind for SR's although my next project is three phase.
A three phase sat reactor would be very cool to find. Perhaps it would stop
the uncontrollable flaming I understands always occurs at low break rates on
a DC Coil ASRG. Is there such a thing as 3 phase sat reactors?
YES, I mostly see common core 3 phase sat reactors in old MILLER and HOBART welders (along with the more commonplace scrs nowdays).... 




I

guess I
could use three if they weren't too massive. In theory once the rotor is
moving faster, the power becomes proportional to the Break rate up to the
current/cap size max.

Thanks all,
Jim Mora



-----Original Message-----
From: Tesla list [mailto:tesla@xxxxxxxxxx]
Sent: Tuesday, April 18, 2006 7:08 PM
To: tesla@xxxxxxxxxx
Subject: RE: saturable reactor vs choke

Original poster: "Jack King" <ekklekktikk@xxxxxxxxxxx>




>From: "Tesla list" <tesla@xxxxxxxxxx>
>To: tesla@xxxxxxxxxx
>Subject: RE: saturable reactor vs choke
>Date: Tue, 18 Apr 2006 17:13:04 -0600
>
>Original poster: "Jim Mora" <jmora@xxxxxxxxxxx>
>
>Hi Gerry, Steve, all,
>
>If you can come up with a silicon based solution that is comparable to the
>375 lbs of copper and iron in my truck, I'll be cutting the copper off for
>the scrap yard post haste!

...Well I wouldnt wheel it to the curb just yet...I have yet to find
a suitable firing card and triacs to approximate what a S-R and old
slide chokes do - I mostly roll such systems for NEON people, so our
HV transformers arent presented with a big cap and spark gap on the
end...but hey, silicon steel and copper fetch good money these days
(and then it's of to Mexico or China)

>I'll run it up to 15KVA on hot water heater elements and measure the
current
>draw verses the control voltage. It will be interesting to see how much
>linearity it actually has. It would be worth buying one more element I
>suppose (4500w/220v) which would run very close to the spec plate. Is there
>anything you would like me to test? I will be scoping the wave form.

You may want to parallell a dumb 0-300 V meter on the load, It would
be interesting to see how attenuated the volatge is at startup with
your load parked on it.

>I will
>over kill the DC by a few amps and regulate it.

I think your gonna have MASSIVE heat from the elements before you get
near 90 volts dc...Just a hunch from past experiments (but mine have
been with "240" v units )...


>It will be interesting to study what happens on a Jacob's ladder. I'll run
>the pig up to 2x 5kva max.

THAT sounds like fun!

>We will know more about the inductive/current behavior of this beast by
next
>week. Be assured that I have no desire to plot the full 90 volts control on
>my pig since I want to be on the conservative side of whatever knee there
>is. My neighbors would not like a brown out. There are six of us on one pig
>which has blown up before.

Yeah, your 5 kva pig wouldnt like you much...and hopefully you werent
the culprit on the last pig-popping!


>Silicon, Germanium, Fiber, it's all good. Leave me the copper, silver, and
>gold!
>
>Jim Mora

ANxious to here of your findings Jim...and I may be able to help you
find some suitable smaller saturable reactors...I run into them in
things like old induction heaters and forklift chargers all the time!

Jack



>-----Original Message-----
>From: Tesla list [mailto:tesla@xxxxxxxxxx]
>Sent: Tuesday, April 18, 2006 1:23 PM
>To: tesla@xxxxxxxxxx
>Subject: Re: saturable reactor vs choke
>
>Original poster: "Gerry  Reynolds" <gerryreynolds@xxxxxxxxxxxxx>
>
>I bet all cores have a less than ideal BH knee meaning there is some
>softness to it and I suspect that this helps with the "infinite"
>current problem.
>
>Gerry R
>
> >Original poster: Steve Conner <steve@xxxxxxxxxxxx>
> >
> >Hi Gerry,
> >
> >>What happens if the load is a PIG where the SG is firing???  It
> >>seems like the load wont limit the current then
> >
> >I think you just have to hope that the saturable reactor has enough
> >stray inductance left over, even once it's saturated, to ballast the
> >pig enough that the spark gap can quench. My gut feeling is that it
> >probably would work fine. From reading the archives, it seems people
> >successfully use ungapped variacs as ballasts, and these probably
> >run in saturation most of the time.
> >
> >When I really think about it, it seems that a small ballast choke
> >sized to run the maximum power you want, combined with a pair of
> >back-to-back SCRs wired like a huge lamp dimmer, would function
> >identically to a SR, but be a good deal smaller and lighter. But i
> >guess we want to keep the silicooties out :-<
> >
> >Steve
> >
> >
> >