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.
Two sensors are used in this simple remote-control circuit, one to switch on and one to switch off the...
Using old germanium transistors like the CK722, this circuit has good gain. We found it in a...
We found this configuration in a 1974 publication. Transistors can be replaced with equivalents such as...