This circuit was found in the Linear Applications Handbook of the National Semiconductor of 1994. Some of the components used are not easy to obtain, but equivalents can be used.
The circuit presented is from the Linear Databook of Motorola of 1990. With it we emulated a NOR gate...
This circuit was obtained in a 1977 magazine, but it can still be assembled with BC548...
This circuit produces sounds that depend on the measured voltage and that can be compared with a...