This timer, like the previous circuits, uses a currently uncommon integrated circuit. The time is given by capacitor C1 and R2 which has the range of values indicated in the diagram.
This high voltage source for gas LASER was found in documentation from the 1990s. The circuit is...
Equivalent comparators can be used on this AND gate. We found it in a Popular Electronics from the 90s. Power...
A NOR gate can be improvised using one NAND gate of a 4011 as shown here. The diodes are...