Suggested by National Semiconductor in documentation from the 90s, this circuit makes use of an operational of the time. The configuration can be applied to modern equivalent components
This circuit was found in American documentation from the 1960s. The operational amplifier is from that...
This two-door doorbell was found in a 1990s US publication. The circuit is still current as...
This circuit is from a National Semiconductor manual, appearing elsewhere on this site. The...