Flood alarm (CB7994E)

This circuit is from a 90s Popular Electronics. The transistors are of general use and the buzzer is a Sonalert type.

1 mA current drain (CB8850E)
This circuit was found in 90s Radio Electronics. The transistor can be any general purpose....
Monostable 4013 (CB11123E)
The circuit below shows how to obtain a monostable from a CMOS 4013 flip-flop. The actuation time...
Drift compensation for transducer (CB7367E)
This circuit is from Philips' 60s documentation. The circuit can be applied to modern operational...