Based on a 555, this 80's American documentation circuit detects the voltage of a battery and can then disconnect the charger. The transistor may be a general purpose type.
This is one of the first solid state laser projects. It was found in the June 1972 issue of Radio...
The integrated circuit used in this project is not common today. It was found in a 2000...
This 3-decade operating range VCO was found in a 90s Popular Electronics. The circuit uses...