We found this circuit in a 1977 National Semiconductor Databook. The circuit can use other FETs like the BF245 and has an input impedance of 10 megohms. The circuit gain is unitary.
Found in Motorola's 1965 manual, this full-wave dimmer controls a load that depends on the used...
Found in American documentation from the 90s, this circuit uses components that are still common...
This relaxation oscillator with solid-state triggering element was found in an old European...