Found in a 90s Popular Electronics, this circuit excites a 40 kHz ultrasonic transducer. The transistor can be a BD135 or other medium power.
This circuit was obtained in Motorola documentation from 1969. The components are from that time. In...
We found this circuit in a Poptronics of the 90s. The circuit operates from 100 kHz to 30 MHz and...
We found this amplifier with 50 MΩ input resistance in the May 1989 Radio Electronics magazine. The...