ZAPPER (Health Hazard?)

[Ron Nossaman]

Succinct, thorough, factual, informative, and somewhat disturbing a little
ways into the personal revelations. I'll give it a 9, because it's still a
little hard to dance to. It's a keeper.

It's interesting that the good Dr. Frankenstein no longer claims the creature.

Ron

>Here are some tidbits:
>
>- The "Zapper" was initially built as a work-around (not solution) for the
>verdigris problem. Unlike other work-arounds which are still used, any
>endorsement for this application has been withdrawn. In case that was
>unclear...
>
>- For a change, it's the inventor, not the user (us) who withdrew
>endorsement for using the device on center pins. Francis Mehaffey does NOT
>recommend using the zapper on center pins.
>
>- The entire device must be considered a disclaimer: "For Professional
>Use". As a byproduct of it's very function, it could be considered fair
>game for the OSHA crowd, and for good reason.
>
>- Like the electric chair, it's the amperage, not the voltage doing the
>work. The implication of this is that the secondary windings must be able
>to withstand a direct short (intermittently), without overheating and
>burning the insulation from, and thereby shorting or opening the
>transformer's secondary windings.
>
>- This would seem to exclude a typical light duty potentiometer as a
>regulating/adjustment device. A heavy-duty wire-wound resistor (ceramic
>housing) would be more appropriate for sharing and/or bypassing this much
>amperage and the related heat. Anything less 'becomes' the fuse.
>
>- Similarly, the entire thought of built-in safety (fuse) would be
>self-defeating. A fuse is, intentionally, the weakest link, meaning it
>would always fail as soon as the electrodes (blades, probes, whatever) were
>applied to a part. In abstract, the "part" becomes the fuse on the output
>or secondary side of the transformer, but in the case of a [disqualified]
>center pin or regulating screw, these are far more resistant to melting
>than any fuse, fusible link or circuit breaker. The potential -- amperage
>-- is therefore shared between the part ("load" in electro-speak) and the
>windings of the transformer.
>
>- The transformer should have a *minimum* of a 1-amp rating. More is okay,
>in fact better, but at the expense of weight, size and cost. Less will
>guarantee the transformer become toast (or worse). The fact that the
>secondary is 12 volts is more a matter of  cost and current availability.
>The 12 volt variety are easier to find with this kind of amperage rating;
>likewise are less expensive, and may be found in reasonable sizes and
>weights. In the old days, powering the filaments of dozens of vacuum tubes,
>finding a 6-volt transformer (or portion in the event of multi-taps) with
>this kind of amperage capacity would have been more common than  today.
>
>- As mentioned by someone, the prongs may be fabricated from spring steel.
>Satisfactory materials include metal strapping, traditional soundboard
>steels, and hacksaw blades. Working with these materials is different than
>other forms of steel, and is beyond the scope of this reply. The portion
>that separates the blades may be any non-conductor -- wood, Plexi,
>bakelite, etc.
>
>- I wouldn't be overly concerned with 12 volts at 1 amp or so. I've
>encountered much higher potential when blindly reaching under the dash of
>my car. However, like other hard lessons, I learned not to wear rings and
>metal watch bands while reaching under the dash (!)
>
>- The *primary* side of the transformer is another story, and anyone is
>fair game. The results depend on a number of things: the person being
>grounded or not, standing on concrete or other moisture retainer, touching
>another object to complete the circuit, and many other possibilities. In
>this case, the person becomes the path of least resistance, not necessarily
>the fuse.
>
>harvey


 Ron