Suggested by Siliconix in documentation from the 90s, this amplifier has its gain digitally selected. The components are from that time, not easy to find today.
Found in a 1965 Electronic Design, this high voltage circuit uses period transistors. Its purpose...
Found in a manufacturer documentation from the 1980s, this circuit supplies currents that depend on...
This variable filter that lets frequencies from 500 Hz to 1500 Hz pass through was found in a...