| 摘要 |
Equipment (1) is coupled up in such a way that an ultrasonic transmitter (2) is continuously switched on and off at different frequencies. When the ultrasonic transmitter is switched on, the frequency of the ultrasound goes continuously up and down in a preset time interval. On/off-switching frequency of a first frequency generator (3) is also random. An Independent claim is also included for a device for scaring off rodents with an ultrasonic transmitter.
|
