This circuit was found in a 1964 Electronic Design. The circuit can be implemented with equivalent modern transistors. Note the high supply voltage.
We found this configuration in documentation from the 1970s, but all components are current. If a...
The SLB0686A integrated circuit used in this application is not currently common. The circuit is...
Found in a 1980s documentation, this circuit uses a photo-Darlington. There must be an optical...