Rotary actuator input for load control and in particular a lighting system

摘要

The control of a load, such as a lighting system, has an actuator module (10) coupled to the load control stage (11). The actuator has a manually operated rotary knob (14) with a coupled absolute encoder (16) that provides pulse outputs (C1,C2) indicating the amount of input rotation. The signals are phase-displaced and are coupled to a clock generator (17) and a decoder (18). Both stages provide input to a bidirectional counter that tracks input position of the knob. The absolute position value generated by the counter is compared (23) with a second counter output (24) that responds to the power output control logic stage (22).