This circuit is from a Radio Electronics magazine from May 1986. Observe the voltages applied to the capacitors, taking care that the capacitor under test can withstand them.
This circuit was found in an American documentation and can be added to common amplifiers of any...
This circuit reinforces signals in a frequency range between 1500 and 2000 Hz for use in...
This simple circuit indicates, through an LED, when the water level of a filter (or other kind of...