This rain, flood or leak sensor was found in a 90s Popular Electronics. All the components used are common today. The transistor can be the BC548.
In a transmitter sequencer we have a high input impedance and a low output impedance. The voltage...
This basic configuration aof a touch switch controls a relay. Power supply can be 5, 6 or 12 V...
This circuit amplifies signals from low impedance sources as microphones, transducers, etc. For...