Abstract: An electronic fence system comprises a fence wire which radiates a radio signal for defining a boundary; a transmitter electrically connected to the fence wire and transmitting a boundary radio signal including a mode selection signal; and a receiver attached to the pet, which receives the boundary defining signal with respect to a pet's approach to the fence wire, and which, depending on receiving the shock mode, applies an electrical shock only to the pet depending on receiving the shock mode, or depending on the shock after vibration mode which indicates a mode giving a shock after vibration, after vibration or vibration with a sound, applies an electrical shock to the pet if the boundary defining signal is continuously received or does not apply an electrical shock to the pet if the boundary defining signal is not received. If the pet has a hearing loss, or the circumference is noisy, a warning signal can be given through a touch to the skin of the pet.

Abstract: An electronic fence transmitter is comprised of a fence wire buried in a yard; a digital-analog (D/A) converter, a wire voltage amplifier, a data amplifier, a power amplifier for power-amplifying a data signal that is outputted from the data amplifier; a voltage detector that is connected in series to the fence wire; a comparator for comparing the detected voltage of the voltage detector with a reference voltage; and a controller by which the D/A converter is controlled according to a signal inputted from the comparator and a voltage applied to the fence wire increasing gradually until a value of the detected voltage is larger than the value of the reference voltage. A distance for receiving the signal from the fence wire is set as constant without regard to an installation length or area of fence wire.

Abstract: An electronic fence system comprises a fence wire which radiates a radio signal for defining a boundary; a transmitter electrically connected to the fence wire and transmitting a boundary radio signal including a mode selection signal; and a receiver attached to the pet, that receives the boundary defining signal, and that generates either electrical shock only, or a combination of electrical shock and vibration, or electrical shock and vibration as well as sound depending on the mode selection signal. If the pet has a hearing loss, or the circumference is noisy, a warning signal can be given through a touch to the skin of the pet. Since a vibration is applied first, and the shock follows it, no severe shock need be applied to the pet that will return into the confined area after having received a vibration. A pet's activity is restricted in a predetermined area.