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

Re: Getting zapped by my unpowered Secondary

Original poster: "Joshua Lovato by way of Terry Fritz <twftesla-at-uswest-dot-net>" <jlovato-at-newmexico-dot-com>

I have had this same problome with my small 2.75" diameter coil. after
powering it down if I put my had over the secondary I get a farly good
static shock. The static charge goes away after a while if you want to wate
a little bit before you grab your coil. I used epoxy to cover the secondary
and it seems to be an excelent dialectric. I think that the high potentual
petween the turnes of wire in the secondary charges up the "capicitor"
formed between the wire and the air by the coating of epoxy. I played around
with another coil that is uncoated and about the same size, whitch when is
placed with in the RF field of the powerd coil, also emits arcs. It dosent
seem to retain a static charge. This seems to sugest that the epoxy or
polyethylene acts like a good dialectric capacitor and perhaps, is less
lossy than other materials whitch dont seem to retain a charge or quickly
lose it. Just a thought :-)


----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Thursday, February 08, 2001 4:59 PM
Subject: Re: Getting zapped by my unpowered Secondary

> Original poster: "Charles Hobson by way of Terry Fritz
<twftesla-at-uswest-dot-net>" <charles.a.hobson-at-btinternet-dot-com>
> ----- Original Message -----
> From: Tesla list <tesla-at-pupman-dot-com>
> To: <tesla-at-pupman-dot-com>
> Sent: Thursday, February 08, 2001 12:29 AM
> Subject: Getting zapped by my unpowered Secondary
> > Original poster: "Ray Robidoux by way of Terry Fritz
> <twftesla-at-uswest-dot-net>" <robidoux-at-basystems-dot-com>
> >
> > Hi All,
> >
> > I have just completed the build of a 2.5" coil, and have
> > experienced a strange problem. When I grab hold of the
> > secondary to adjust the height for coupling purposes I
> > get a fairly painful zap. I am wondering if anybody else
> > has seen this and what the cause may be. I assume it must
> > be some sort of parasitic capacitance formed by the wire
> > in the coil and one of the dielectrics involved in the
> > construction, with the ambient air-to-ground forming the
> > other plate. If so which dielectric is involved (coil
> > form, wire insulation, sprayed polyethylene)? And why
> > haven't I heard of this before from some other coilers?
> > I have solved the problem for now by wrapping my entire
> > secondary in Saran Wrap. This was a good solution and it
> > is working well now but I would still like to know what
> > is happening.
> >
> > Ray
> Hello Ray,  I've never been zapped by residue electric charges in the way
> you described. Saran wrap is pretty thin stuff so I don't think it would
> hold off very high static voltages, but it probably would insulate you
> against 120V ac. I've been "zapped" by ac power which managed to find its
> way into equipment I worked on even though the power switch was off. This
> was because of poor grounding. Anyway, I always make it a point to UNPLUG
> before working on anything like TC's. Be careful and happy coiling.
> Chuck