This circuit was found in ancient American documentation. Equivalent operational amplifiers can be used. The power supply must be symmetrical. The circuit provides an average output.
For trigger high power loads connected to the power grid, nothing better than using a TRIAC. For...
This circuit with 1% regulation aims at replacing mercury cells. We found it in a 1967...
With this circuit it is possible to control a relay up to 100 mA with an extremely low input...