We found this circuit in the Encyclopedia of Electronic Circuits Volume 5 from 1995. It uses a 3-terminal transducer from the time. The circuit is triggered by light.
November 3, 2015 - Mouser Electronics, Inc. is now shipping the new Intel® Quark™ microcontroller...
This circuit produces a sinusoidal signal whose frequency can be calculated using the formula next...
This circuit is suitable for isolating audio signals, as it has very low distortion. The used...