(under subclass 17) Subject matter wherein the automatic control means is responsive to light or utilizes a photo-sensitive circuit.
SEE OR SEARCH CLASS
250, Radiant Energy,
200+, and the classes and subclasses specified in the Notes to the definition of these subclasses for photocell controlled circuits and photocell apparatus.
323, Electricity: Power Supply or Regulation Systems,
221, 902, for light responsive electric space discharge device voltage magnitude control systems.