This circuit was found in a 90s Popular Electronics. With it, using a 4066, it is possible to control between 1 to 100 the gain of an operational amplifier like the 741.
This circuit can be implemented with standard photodiodes consisting of a two input optical AND gate....
This TTL counter was found in the March 1991 issue of Radio Electronics magazine. The circuit is...
The circuit shown in figure uses a photodiode as a sensor element and its main feature is to have...