PURPOSE: To prevent the approach of moths and to facilitate the cultivation of non-chemical vegitables by radiating the cry of a bat. which is artificially generated.
CONSTITUTION: A clock signal generating circuit 11 generates a 1st clock signal as the standard of the frequency of an ultrasonic wave to be generated and a 2nd clock signal used to generate a timing signal for setting the waveform of the ultrasonic wave to be outputted. The 2nd clock signal is inputted to a timing signal generating circuit 12 to generate plural timing signals by the frequency division of a counter or by a microcomputer, etc. The 1st clock signal and timing signals are inputted to a saw-tooth wave generating circuit 13. This circuit 13 inputs the 1st clock signal frequency to an up counter and when the counter is cleared with the timing signal, this circuit outputs a saw- tooth wave close to the basic ultrasonic wave song pattern of the bat on which the ultrasonic wave is superimposed; and a transmitter driving circuit 14 amplifies it and an ultrasonic wave transmitter 15 radiates the ultrasonic wave to a space.
FUNAKOSHI NORIHIRO
SAKATA MASAO
