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.
We found this circuit in a publication for radio amateurs in 1974. The bipolar transistors can be...
Found in a 1980s American documentation, this circuit has a current consumption of only 1 mA. The...
This adjustable power supply was found in Ferranti's transistor manual from 1974. Power...