We found this circuit in a Radio Electronics issue from July 1969. The lamp remains on until C1 opens. The time is given by capacitor C1.
In the figure we have a high stability voltage reference, providing a voltage of 10 V at the...
We find this circuit in an American 1980s documentation. Integrated circuits are uncommon today as...
The diagram is from a 1990s document. The integrated circuit must be equipped with a heat sink. The...