This alarm with sensors in series and parallel was found in the 1995 Encyclopedia of Electronic Circuits. The number of sensors can be changed at will.
The filter shown in the figure, using only an operational amplifier, is characterized by allowing 1...
Found in a 90s American documentation, this circuit can be used as a shield, just change the...
Found in a Philips' 1968 documentation, this circuit is slightly different from the previous one. The...