Electric fence charger

From RetroTech, the online museum of 20th century technology.

The electric fence charger on display in the museum was sold in 1949 by the International Electric Fence Co. of Vancouver, Washington. It operated from AC line voltage and utilized a four-pin vacuum tube. Some of these chargers contained electro-mechanical vibrators to convert the energy applied to the fence such that it was much higher in voltage and frequency than the energy supplied from the 60-Hz AC power line.