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.
Using an old integrated circuit, this low power amplifier, on the order of a few watts, includes tone...
This circuit can be applied to other 3-terminal regulators and equivalent transistors can be used....
This circuit that generates a special sound was found in a Popular Electronics from the 90s. The...