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 600-ohm output impedance circuit was found in a Radio Electronics from October 1963. The...
Used with infrared remotes at the time, this circuit was found in a 1991 RE Experimenter Handbook....
The circuit presented was obtained in a technical documentation from National Instruments. The...