This circuit is from American documentation from 1970. It can be designed with a BC558 and for the operational, we can use equivalents. The FET can be the BF245.
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...