This circuit was found in a 1967 US documentation. The circuit applies to modern general purpose transistors. The circuit has no offset. The power supply must be symmetrical.
This circuit was obtained in an old American manual. The circuit is valid for any operational. The...
This two-relay circuit gives drive logic that is clear when analyzing the circuit. In the original...
This circuit, suggested by Philips Components (1980), uses a fast voltage comparator and requires...