On Mon, 03 May 2010 13:48:22 -0400, Bob Engelhardt
wrote:


I've looked inside a number of fence chargers and not one of them was
just a transformer. They all had some sort of timed interruption,
probably to give an inductive kick (I never actually analyzed a circuit).

Bob

That describes the ones I've seen-- and the one I built as a kid using
an automotive ignition coil. But this type specifically says it's
continuous (and sinusoidal output, see below).

Assuming it's the SS-600:-

This Fi-Shock™ Poultry Charger for electric fences is electric powered
and features continuous AC output. Effective for adult chickens and
other large birds, it has a 1 mile range under ideal conditions and is
covered by a 1 year limited warranty.

Voltage:

Input Voltage: 110-120 VAC, 60 Hz, .027 A, 10 W
Output Voltage: 800 VAC +/- 20% open circuit voltage

The manual further says it's 8mA +/-2mA short-circuit current.
http://www.fishock.com/resource/uplo...structions.pdf


Here is an intermittent version that just cycles the power to the
transformer using a 555 timer and a triac. It's publically there in
all the gory detail because it allegedly killed a 4-year-old boy.

http://www.cpsc.gov/library/foia/foi...e/fidoshc3.pdf

The transformer is listed as made by the manufacturer (Fi-Shock). Not
surprising, since it would be much of the cost. Note the presence of a
magnetic shunt to increase the leakage inductance (page 13).