This circuit was found in a 90s Radio Electronics. It produces an ultrasonic signal in a special transducer at the frequency of 2.25 MHz. No information was given about the transformers.
Suggested by Siliconix in documentation from the 90's, this circuit supports current equivalent...
This circuit decodes a 1800 Hz tone used in communications. The circuit is from an American...
This circuit was obtained in 1981 documentation. It is an FM transmitter that can serve to emit...