This circuit, for frequencies up to 100 kHz, was found in American documentation from 1970. The circuit can serve as a reference for projects with modern equivalent components.
This circuit was found in Radio Electronics from the 90s. It uses a transconductance operational...
This circuit was obtained in a 1982 publication. There are many types of car alarms available to...
We found this filter in documentation from the 1980s. The operational amplifier used is uncommon...