The FETs of this circuit can be the BF245. The circuit is from an old documentation and can be used in the amplification of infrasonic waves, of a sonic attack, for example.
Indicated by a Popular Electronics of the 90s originally to measure the light determining the exposure...
Other operational amplifiers series, such as the MC34072, MC34074, MC35071, MC35072, MC35074 d...
Found in American documentation, this circuit shows how to polarize a FET in bootstrap mode. The...