This circuit was obtained from an 80's EDN. The components used are still common. The circuit can be used as a shield and the frequency is approximately 775 Hz.
The purpose of this circuit is to increase the sensitivity of a common multimeter in its voltage...
This is the modern version of the Galena radio in which the detector is a germanium diode (which can...
This circuit allows the measurement of very weak currents indicated on an analog instrument or...