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.
This circuit, from the 90's, is intended for operation with vinyl record players of the time, as...
Using a zener diode it is possible to change the linearity of the scale of an analog instrument by...
Found in American documentation from the 1980s, this circuit prolongs the ringing of a doorbell or chime...