Found in 1969 documentation, this circuit supplies a load after an interval given by R1 and C1. These components can be changed to other times.
Found in a 1980s documentation, this amplifier uses an operational aplifier of the time with two...
This circuit was found in a Popular Electronics from the 90's. The frequencies depend on the...
This is a Philips commercial circuit from the 1980s. The circuit must be powered by 28 V and its...