Re: Electrometer design (fwd)

[Steven Roys <sroys@xxxxxxxx>]

---------- Forwarded message ----------
Date: Fri, 9 Jul 2004 13:27:36 -0500
From: Dr. Resonance <resonance@xxxxxxxxxx>
To: High Voltage list <hvlist@xxxxxxxxxx>
Subject: Re: Electrometer design (fwd)


You can also use a field effect transistor (FET) and this gives a reliable
flash at distances up to 50 miles as the storm approaches.  If anyone sends
me a SASE I will send them the circuit.  Very simple with one FET, a few
resistors, and a few caps.

Dr. Resonance

Resonance Research Corporation
E11870 Shadylane Rd.
Baraboo   WI   53913
>
> ---------- Forwarded message ----------
> Date: Fri, 09 Jul 2004 09:34:49 -0400
> From: Charles Brush <cfbrush@xxxxxxx>
> To: High Voltage list <hvlist@xxxxxxxxxx>
> Subject: Re: Electrometer design (fwd)
>
> >
> >
> >Could someone repost that NE-2 relaxation oscillator or tell me where I
> >could find the posts.  Is this a static detector ??
> >
> >Thanks,
> >
> >Shaun Epp
>
>
> Shaun,
>
> The design is incredibly simple.  Basically you have a little NE2
> lamp in parallel with a capacitor with one side attached to ground
> and the other to an elevated and sharply pointed rod.  As the local
> field increases current will flow through the circuit causing the cap
> to charge and periodically discharge through the NE2 causing it to
> blink.  The faster it blinks the stronger the field overhead.  I
> tried this a few summers ago but I can't remember the cap value I
> used (anyone have suggestions?).  It took a very close storm to get
> it to work but it was pretty neat when it did.  Quite sobering really
> considering what it was telling me about the field immediately
> overhead.  Naturally you might not want to put the antenna up too
> high since this is essentially a lightning rod and a direct strike
> would not be good!  Mine was up just above the roofline of our house.
>
> Another type of sensor just replaces the cap/NE2 with some type of
> current meter allowing you to watch the current go up as the local
> field intensifies.  I am setting up one of these with a Keithley
> current meter and will let you know how it works when we get our next
> storm.  A variation on this particular design uses a razor blade
> coated with an ionizing radiation source to increase sensitivity.
> There is a web page someplace about it if you do a search.
>
> Yet another variation dates back to Ben Franklin and is knows as
> "Franklin's Bells".  This consisted of two bells on insulated
> supports with a metal clapper suspended between them.  One bell was
> connected to a lightning rod above the house while the other was
> connected to ground.  The rod would collect charge as storms
> approached, the clapper would act as a charge transporter moving
> charge from the charged bell to the grounded bell.  The faster the
> ringing the stronger the overhead field.  Really a simple and
> ingenious design, though once again a tad dangerous!
>
> Zap!
>
>
> Charles Brush
>
>
>