Found in a 90s Popular Electronics, this circuit provides sinusoidal signals at frequencies given by the components, as shown in the table beside the circuit.
With this luminous remote control, which we found in a 1990 publication, using a flashlight you...
We found this circuit in a 1967 Electronics World. The circuit can be designed to control other...
This circuit can be used in a signal level indicator with LEDs. The circuit is from an Electronics Now...