This circuit was obtained from an 80's Radio Electronics. The circuit decodes “scrambled” or sinusoidal encoded signals by providing an audio signal at the output.
This is yet another simple LED driving game circuit that appears in several other versions on this site....
We found this circuit in a manual of optoelectronics from Texas Instruments. In it photodiodes or...
This interesting circuit is from a 1988 documentation. It is a matrix of diodes that converts...