This simple rain, leak or moisture detector circuit appears in other places on this site with slight variations. This was obtained in an English documentation from the 70s.
The time constant for this circuit found in a 1973 publication is given by R and C. The shot is...
Used with old projector films, this circuit found in Signalite documentation from the 1980s,...
This circuit generates damped sounds imitating a drum or other percussion instrument with...