This high impedance amplifier is from 1985 documentation by General Electronic. The amplifier with FET at the entrance is from the period and the source is 9 V.
This circuit is from a Radio Electronics magazine from December 1958. The indicator instrument is analog...
This circuit sends signals to a shortwave radio (range 3 to 7 MHz) at a distance of a few tens of...
This circuit was found in an Electronics World of 1968. It can be applied to any modern triac and...