We found this circuit in an old documentation. It can be elaborated based on modern components. The double transistor can be replaced by a matched pair.
The normal use of a 4520 as a divide-by-16 counter is shown in Figure bellow. In the normal...
This flasher was found in an 80's Electronic Engineering but can be easily implemented with modern...
This micro-transmitter for the FM band was found in documentation from the 90s. The circuit is...