Found in the May 1975 issue of Radio Electronics magazine, this circuit turns on after a certain amount of time. This gives the owner of the premises time to leave before the alarm is activated.
This circuit is from old European documentation. R1 depends on the output voltage of the...
This circuit can be used in an experimental link for educational purposes. based on an integrated 4093....
This circuit provides just over ½ W to a small speaker. We found this configuration in an old...