This circuit was found in 1980s American documentation. The transducer is a piezoelectric capsule and the power supply voltage can be between 3 and 18 V.
The LS4558 integrated circuit is a double 741. The filter response curve is given next to the...
This motor control using transistors was found in a recent English publication. The circuit is for...
This circuit from a 90s Popular Electronics, decodes the old analog TV signal. It works with a...