This circuit activates a warning lamp when an incoming call is received. We found it in an 80s Hands-On Electronics. The diac and triac can be of any type.
This circuit can generate signals from 2 to 15 MHz or 4 to 22 MHz depending on the used components...
This interesting configuration was found in a 1965s Electronic Design. It makes use of components of...
The figure shows how to obtain a digitally programmed resistance using the 4066. The circuit is...