Automatic electric fence charging system

Claim 2

A fence charging system for impressing a shocking potential upon a ''''loaded'''' fence at predetermined time intervals, said fence being adapted to be ''''loaded'''' or ''''unloaded'''' depending upon whether the electric resistance presented by the fence is below or above an arbitrary voltage, said fence charger system including a capacitor, means for charging the same to a predetermined maximum potential and thereafter discharging the same after said potential has reached a predetermined value, said fence charger including means for utilizing said discharge in generating a high shocking potential, said system including sensing means for connection to a fence load, said sensing means impressing a low direct voltage of the general order of about 50 volts continuously on said fence durint the time that said fence is ''''unloaded,'''' and means controlled by normal sensing voltage conditions in said sensing system for disabling Said fence charging system so long as said fence is ''''unloaded,'''' said means becoming inoperative when the voltage conditions in said sensing system charge in response to fence ''''loading,'''' whereby said fence charger operates to impress high potentials at time intervals on said ''''loaded'''' fence.

Claim 3

An automatic electric fence charging system comprising a sensing system including a resistance network, said sensing system being adapted to be connected to a fence to be charged, means for energizing said sensing system so that a maximum voltage of no more than about 50 volts can normally be impressed upon said fence, said fence load normally being adapted to permit a minute current to flow from said sensing system to ground with the IR drop being such as to maintain said sensing voltage, electric fence charging means including a relaxation type oscillator having a capacitor and a capacitor discharge circuit for permitting pulse discharge of said capacitor when the capacitor potential reaches a predetermined value, said capacitor thereafter being charged relatively slowly to repeat the discharge cycle, and means responsive to the voltage conditions in said sensing resistor network for disabling said capacitor charging system and preventing the potential across said capacitor from reaching a breakdown value so long as said fence remains ''''unloaded,'''' the ''''loading'''' on said fence reducing the fence load and increasing the current from said sensing system whereby said means responsive to the voltage conditions operates to permit said capacitor to reach a pulse discharge value and operate the fence charging system in a normal fashion.

Claim 4

An automatic electric fence charging system comprising a sensing system including a resistance network, said sensing system being adapted to be connected to a fence to be charged, means for energizing said sensing system so that a maximum voltage of no more than about 50 volts can normally be impressed upon said fence, said fence load normally being adapted to permit a minute current to flow from said sensing system to ground with the IR drop being such as to maintain said sensing voltage, electric fence charging means including a relaxation type oscillator having a capacitor and a capacitor discharge circuit for permitting pulse discharge of said capacitor when the capacitor potential reaches a predetermined value, said capacitor thereafter being charged relatively slowly to repeat the discharge cycle, and means responsive to the voltage conditions in said sensing resistor network for disabling said capacitor charging system and preventing the potential across said capacitor from reaching a breakdown value so long as said fence remains ''''unloaded,'''' the ''''loading'''' on said fence reducing the fence load and increasing the current from said sensing system whereby said means responsive to the voltage conditions operates to permit said capacitor to reach a pulse discharge value and operate the fence charging system in a normal fashion.

Claim 5

The system according to claim 2 wherein said sensing portion of the system includes at least one resistor whose value is in the megohm range, said resistor having one end for direct connection to a fence, and voltage dividing means connected to said high resistance and transistorized means connected to said voltage dividing means, said transistorized means functioning as a switch to control a circuit to said capacitor for controlling the potential level to which said capacitor is charged, said transistorized means itself being controlled by the potential level at said voltage dividing means.