This circuit recognizes a tone determined by the tuned input circuit (R3 / R4 / C2). The circuit was found in Radio Electronics from the 90s. The 4046 is not a common component today.
This circuit was found in the PC documentation from 1996. The maximum current of the motor is...
This circuit is from the time when the 741 was first introduced. It was published in the February 1971...
Only two transistors are used in this preamp for low-sensitive transducers, such as guitar and...