A mathematical expression is converted and approximations applied to remove complex processes, simplifying the circuitry of system which controls compressor speed in dependence on ambient temperature.
Loading of induction motors is monitored and displayed by meters or alarms by analyzing slip of the armature derived from pulse signals indicating motor shaft speed. A special sensor sensing the motor shaft rotation also provides motor operating temperature signals accompanying shaft rotation speed signals. Corresponding circuitry compensates the load display over motor temperature variations. Also, the motor operating voltage is detected and voltage variations are processed to modify the load display for improved accuracy in the presence of voltage variations and by linearization of the slip characteristic.
