We found this circuit generates signals from 200 Hz to 62 kHz and can be used to repel mosquitoes and mosquitoes. The circuit can be powered from 2 small batteries to 9 V battery.
Found in a Maxim documentation from the 90s, this circuit produces a voltage of 5 V from an input...
Unlike the previous one, this circuit is intended for the reception of frequency modulated signals...
This circuit was obtained from Popular Electronics from March 1967. The transistor used is from...