| 摘要 |
<p>A leather collar (40) worn by an animal has a buckle (41) which enables the ends to be joined and which also contains batteries for a receiver. The receiver (43) is housed in an enlarged section of the collar and has loudspeakers (44) located on either side. An antenna (45) is encased within the collar. The animal is recalled by operation of a transmitter for which a microphone provides signals to a modulator. The modulator drives a generator to which an antenna is coupled. The generator may be for radio, ultrasonic or infra red frequencies and may be modulated using amplitude, phase, frequency or digitally coded signals.</p> |
