improvements in devices and velatori presence with ability to discriminate between viven beings and inanimate objects

摘要

Control circuits for sensing and responding to impedance changes caused by a mammal in contact with or in proximity to an antenna or other sensor. Each circuit includes at least one tuned circuit which is periodically energized to cause it to "ring" at its natural frequency, i.e., to produce damped oscillations. Each tuned circuit includes an antenna or other sensor by which an external impedance is coupled to the tuned circuit. Thus, the oscillations in the tuned circuit are attenuated to a degree determined by the capacitive and resistive components of the external impedance. In the case of mammals, the resistive component is substantial and causes a marked change in the amplitude and duration of the damped oscillations in the tuned circuit, which are then enhanced and/or detected to produce a predetermined control signal.