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 speed control for motors up to 500 mA was obtained in an old European documentation, but it...
This circuit cuts a rectangular signal, and a trapezoidal signal is obtained. The circuit is from...
This low frequency sinusoidal oscillator was obtained in documentation from the 1970s. Operational...