I am wanting to run it from DC, but the energy stored in the inductor
(think boost regulator) is fed to the "resonator coil" when the switch
opens, which drives the output.  Normal output is >55kV and discharge
pulses of appx 3A for some nanoseconds.

So the goal is to rewind for 12V, and to keep the output energy.


On Tue, Apr 21, 2015 at 2:42 PM, Richard Prosser <rhprosser@gmail.com>
wrote:

> I don't like your chances about keeping the inductance the same. A lower
> voltage for the same amp-turns means higher current and less turns.
> Inductance is proportional to the square of the number of turns (until
> saturation) so 1/2 the turns, results in 1/4 inductance.
>
> As it's a solinoid and I'm guessing you're looking at running it from AC =
if
> you're concerned about inductance. The stauration level will change
> according to the position of the solinoid so there may be some sort of
> sweet spot but it's going to be difficult to optimise.
>
> Can you run it from DC? Then the inductance is less important and it's
> simply DC resistance and number of turns (i.e wire guage) to worry about.
> And switching spikes and possibly slower drop out and/or sticking as the
> poles get magnetised. Running at different votages (PWM)  for pull-in and
> hold-in may be an option but is an additional complication. If there's a
> spare pole on a sense switch, you could achieve the same by switching in =
a
> (burden) resistor to reduce hold-in current. Give it pleanty of ampere
> turns to pull in and switch down to enough current to hold in (with flat
> batteries?).
>
> RP
>
> On 22 April 2015 at 08:13, David VanHorn <microbrix@gmail.com> wrote:
>
> > Some things seem to get harder to find as time goes on.  Things like th=
is
> > used to be done all the time, probably from paper nomographs that never
> got
> > enwebified.
> >
> >
> > I have a solenoid coil that I'd like to re-wind from 120V to 12V.
> > The complication is that I need to keep the amp-turns and the inductanc=
e
> to
> > similar values.
> >
> > The original is 70 ohms, 19 layers of 176 turns or 3344 turns.  I wasn'=
t
> > able to measure the inductance due to high series resistance.
> >
> > Seems like this should be possible, and yet I've found precious little =
in
> > data on how to rewind for different voltages.
> >
> > I tried re-winding for amp-turns and had limited success, but the outpu=
t
> > energy was very limited.
> >
> > The device in question is a BD-10AS from ElectroTechnic products.
> > The magnetic field of the solenoid opens a switch which is integral to
> the
> > function, and so I need about the same level of flux.  I am theorizing
> that
> > the reason for low output was the lower inductance of my 400 turns of #=
19
> > vs
> >
> > I need to use it far from an outlet, and powering it with an inverter i=
s
> > almost certainly going to result in a smoked inverter. I thought of a
> > series pack but the idea of a battery at 120V with any real output
> current
> > is pretty scary.
> > --
> > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive
> > View/change your membership options at
> > http://mailman.mit.edu/mailman/listinfo/piclist
> >
> --
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