A system and method for a compressor may include an inverter drive connected to the compressor that receives electric power and modulates a speed of the compressor by modulating a frequency of the electric power. A control module connected to the inverter drive monitors compressor power data and compressor speed data from the inverter drive, and calculates a saturated condenser temperature of a refrigeration system associated with the compressor based on the compressor power data and the compressor speed data.

Variable speed compressor protection system and method

An automatic control for various domestic appliances has a ferrite core which surrounds the run winding for the drive motor of the appliance. The run winding represents the primary winding for the ferrite core, which has a secondary winding at which a brief output voltage is generated whenever the run winding current changes direction. This sensor in combination with a voltage zero detector circuit and post-connected logic circuitry generates a voltage pulse and a phase pulse which are respectively related to the voltage level of the drive motor and the motor output torque which is required to operate a movable member in the appliance. A microcomputer is utilized to generate a representative digital phase number which corresponds to the torque expended in the appliance. The phase number is utilized in various programs of the microcomputer for automatically controlling various functions of the appliance as well as other events in an operational sequence upon the attainment of selected torque levels.

Electronic control for a domestic appliance

An electrical circuit for providing electrical energy to an electric motor which operates a liquid pump. The motor and the pump are adapted to be submerged in the liquid which is pumped by the pump. The circuit disclosed herein senses the phase angle between the current and the voltage applied to the electric motor. When the phase angle indicates that the motor is operating without a load, the circuit deenergizes the electric motor. Thus, the motor and the liquid pump are protected against damage. Recognizing that harmonics may exist in the current flow through the motor, the circuit provides for obtaining a filtered signal proportional to the fundamental frequency of the current flowing through the motor. Thus, an accurate measurement of the loading of a motor is obtained. The circuitry of this invention also provides an accurate method of compensation for applied line voltage variations, so that a change in the applied line voltage does not produce a false indication that the motor loading has changed.

Pump and electric motor protector

A water pump protector which includes electrical circuitry through which an electric motor is energized. The electric motor operates a water pump. The circuitry senses the phase angle between the voltage and the current applied to the electric motor. When the phase angle indicates that the motor is operating without a load, the circuitry deenergizes the electric motor. Thus, the water pump is protected against damage which may occur when the water pump is operated without pumping water.

Water pump protector

A system and method for calibrating parameters for a refrigeration system having a variable speed compressor is provided. A compressor is connected to a condenser and an evaporator. A condenser sensor outputs a condenser signal corresponding to at least one of a sensed condenser pressure and a sensed condenser temperature. An inverter drive modulates a frequency of electric power delivered to the compressor to modulate a speed of the compressor. A control module is connected to the inverter drive and determines a measured condenser temperature based on the condenser signal, monitors electric power data and compressor speed data from the inverter drive, calculates a derived condenser temperature based on the electric power data, the compressor speed data, and compressor map data for the compressor, compares the measured condenser temperature with the derived condenser temperature, and updates the compressor map data based on the comparison.

System and method for calculating parameters for a refrigeration system with a variable speed compressor

A circuit is provided for connection to an AC line and a reactive load which extracts a voltage wave form from the line, the phase of which is adjustable. A pickup to the load extracts a current wave form from the load on the line to the load and converts the current wave form to pulses which are synchronized with the zero crossing or points where the current goes to zero. A phase detector is connected to the voltage wave source and the current zero crossing pulse source and converts the signals to a DC analog output of the phase relationship between the voltage and current wave and this current is used to control by means of a voltage level operated switch, and an external circuit.

Mills Thomas F

Papers

Method and apparatus for electronic sensing of motor torque