This circuit is from a 1968 Motorola power circuit manual. The circuit uses transistors of the time. The passing band is 45 Hz to 100 kHz.
Found in a 90s Popular Electronics, this circuit excites a 40 kHz ultrasonic transducer. The...
This VFO circuit generates signals from 2 Hz to 50 Hz. We found it in Popular Electronics from...
The circuit shown in the figure generates a rectangular signal that depends on R and C, when its...