We found this circuit in documentation from the 90s. The circuit uses components that are still common today, turning off a load after the programmed time. The time is given by the capacitor.
We found this circuit in a 1990 documentation. The operational amplifiers are type 741 and the LED is...
We found this circuit on an Elektor from the 90s. The frequency is given by capacitor C1. The...
Found in National Semiconductor publication from the 1980s. This gain-100 circuit can be...