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.
This circuit safely replaces common locks, since, instead of the key, the opening is made with the...
This amplifier, common in 1986, uses a hybrid integrated circuit that can offer some difficulty to obtain...
This circuit, found in a 1979 documentation, consists of a small inverter that applies a voltage to...