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 is a circuit that should not be used for readers interested in a fair game. The circuit...
This circuit has a general-purpose transistor to compensate for the non-linearity of the generated...
This circuit was found the Optoelectronics Sourcebook by Texas Instruments. Any phototransistor...