This is an interesting configuration of the LM317 voltage regulator found in an EDN from the 90s. The circuit uses an optical coupler and is intended to supply constant current to a sensor resistor.
In the figure we have a current source whose intensity is given by the formula next to the...
This circuit amplifies signals from 0.5 Hz to 300 kHz. We found it in an old documentation. Equivalent...
The circuit we show is a water pump actuator that, in addition to being automatic, has a water...