ZAPPER (Health Hazard?)

[Frank Cahill]

Richard Wagner wrote:
> 
> List,
> 
> I've built, and burned out a couple of "Zappers" over the years using them
> on all kinds of things both piano related and not...
> 
> And "No," just because I've burned a few out, doesn't mean that I've been
> out there charring flange bushings and birdseyes instead of repinning.
> 
> Let's just say that I'm fond of experimentation, and leave it at that.
> 
> Anyway, long ago,  I was told by someone who worked on electrical doo-dads
> for a living, that the Zapper, ala Mehaffey was a "potential death trap."
> 
> I didn't ask him why at the time, because, knowing nothing about
> electricity, I didn't want to appear ignorant.
> 
> Now, years later, I'm still mostly ignorant about electricity, but have
> learned just enough to fool around with it and get myself killed.
> 
> I think that simply going down to Radio Shack, buying the appropriate
> transformer, wiring it up with a plug on one end and shorting it across a
> tight center pin on the other, could be dangerous if not lethal should that
> transformer choose to burn out, fusing the internal widings together
> somehow, and connect you directly into the power grid.
> 
> After all, the thing works by creating a short circuit across the center
> pin thus heating it up, but everything involved gets hot especially the
> windings in the transformer itself.  This is what fuses are in your home
> wiring to protect against...(sort of.)
> 
> Anyway, I could be wrong here folks, and perhaps John Fortiner, Larry
> Fisher, or some other electrical wizards on the List could set me straight,
> but I believe that the simple "Zapper" described in the paragraph above is
> potentially dangerous if not modified somehow...
> 
> Please help me out here as I'd love to continue experimenting without
> killing myself...
> 
>         Richard Wagner RPT
> 
> 


I am not familiar with the zapper, but you are not wrong in worrying
about a shock hazard.  

You could limit current flow by placing a resistor in line with the
output.  I would need to know how much current flow is needed to make
this thing work.  Of course this depends on the output voltage of the
transformer.  Ohm's law would tell you what size resistor is needed for
the voltage output available and the desired current.  

You could also put a fuse in the line between the ac outlet and the
transformer primary winding. That's always done.

With these two circuit additions, the set-up could be safely used...of
course it's not idiot proof.  E-mail me privately if you'd really like
some info.
-- 

Frank Cahill
Associate Member
Northern Va