This circuit works on analog I/O ports and was suggested by an Electronic Design from the 90s. It can be used to work as a shield in projects with microcontrollers.
The operational amplifier used in this circuit is not common today, but it can be implemented with...
This circuit is used to test triacs. It can be connected in series with a resistive load such as...
In the figure we have the configuration of a transistor as a temperature sensor. The circuit is...