Speed control for orbital shaker with reversing mode.

摘要

An orbital shaker apparatus which has a tray for cyclic motion is flexibly suspended from a frame which is flexibly suspended from a plurality of stationary supports. The flexible suspension constrains the tray to move only translationally along one axis with respect to the frame and constrains the frame to move only translationally along one axis perpendicular to the tray movement axis. A single chip microprocessor is used to scan, input store, display and control the speed, duration and control functions for the orbital motion. Embodied in the software of the microprocessor is a real-time closed loop speed control which monitors the actual speed of the orbital motion thru an interrupt facility by calculating the duration of pulses received from an optoelectric sensor. The measured pulse duration is digitally compared to the desired duration and a digital control signal is provided to drive a DC motor which is directly coupled to the drive shaft which imparts the motion. A set speed mode and a reversing mode are selectable by an operator to provide different means for agitation.