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.
The circuit shown below is from the National Semiconductor's 1994 Linear Applications Handbook. The...
A simple electroscope can be made only with a 741, without the need for field effect transistors or other...
This circuit from Delta Products was published in the May 1974 Radio Electronics magazine. The...