This circuit was found in a 90s European documentation. The circuit already includes a powerful amplification stage. The MOSFET can be of any type.
This audio signal relay was found in an American 1980s documentation. The relay is in accordance...
This circuit was obtained from a Hands On-Electronics, an American magazine from January 1987. This...
Using an operational amplifier with FET, this voltmeter has a high input resistance. The circuit has...