This circuit was found in a 1965 Radio Shack documentation. The transistors are from that time. The circuit can be implemented with current transistors and lower voltage supply.
Suggested by Philips in a 1970 publication, this circuit uses components from that time. No...
This circuit is designed to measure very weak currents, in the order of picoamperes. We found it...
This circuit was found in an American documentation from the 80's. The transistor is a...