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.
This 1968 Mullard circuit detects fire by smoke using LDR-type sensors. The circuit makes use of...
Found in the American 73 magazine for radio amateurs, this circuit can test common quartz...
With this circuit it is possible to tune the signals in the 50 MHz band in a common AM receiver around...