This timer for long time intervals is from the 1990 Motorola Linear Databook. The setting applies to other operational ones and component values are given below the diagram.
With this simple tester you can measure the gain of an NPN or PNP transistor. The instrument can...
I found this circuit in an old Argentine publication from 1973. The components are no longer...
Used with telephones at the time, this circuit was found in Popular Electronics from the 90s. The...