This is a CGS62 1.2 Slope Detector. This is an event-driven gate/trigger generating device. It monitors a control voltage, and triggers one of three 5V “gate” output dependent on what the control voltage is doing. The rise has a red LED, the steady a yellow LED, and the fall a green LED.
These gate signals can be used to fire envelope generators dependent on the action of the CV, for example opening a filter when a melody is rising in pitch, and closing it when the melody is falling in pitch. It can also be used to generate gate signals from LFOs, envelope generators, to advance sequencers etc.
The sensitivity pot allows the slope detector to work with either relatively fast events, like the edges of a square wave pulse train, or very slow events, such as the sine output of an LFO being used to drive filter/phaser sweeps.