Found in a 90s Popular Electronics, this circuit uses a 741 to generate frequencies from 0.1 to 30 Hz. Observe the phototransistor feedback.
We found this circuit in a 90s Popular Electronics. It increases the duration of a pulse in a...
This simple circuit detects when a conductive liquid reaches the sensors. The circuit has no...
This converter or inverter uses components that are still common. The transformer is the type...