Abstract: An apparatus for controlling an air distribution system by controlling the speed of a motor associated with a blower to maintain a rate of air flow in the system at substantially a target air flow rate. The apparatus comprises means for controlling a supplied frequency to the motor; means for providing a speed signal representative of the speed of motor; means for providing a frequency signal representative of the supplied frequency from a controller to the motor; means for providing a load signal representative of the load of the motor; means for calculating an air flow rate signal based on the speed signal and the load signal; means for controlling a supplied frequency in response to the target air flow rate signal and the calculated air flow rate signal. The apparatus can apply three different types of algorithm for controlling and compensating the motor.

Abstract: An apparatus for controlling an air distribution system for maintaining a rate of air flow in the system at substantially the target air flow rate, wherein the apparatus detects current speed and torque of said motor and generates said current speed signal and torque signal after detection; receives the current speed signal and torque signal and calculates the current air flow rate in the air distribution system wherein the calculated current air flow rate is compared to the target speed signal of the air flow rate and the current air flow rate is adjusted according to the target speed signal of the air flow by generating a control signal; and controls the motor speed in response to the control signal for maintaining the rate of air flow in the system at substantially the target speed signal of the airflow rate.

Abstract: A power factor correction circuit having an input current for reducing the distortion and harmonics generated in a power line feeding power supply. The power factor correction circuit includes a control switch (such as an IGBT) for producing a control switch current and virtual short circuit; a load for acting as power demand from a load and producing a load current; and one or more of resistors for measuring current within said circuit.

Abstract: A circuit for converting data of a signal line in the form of logical pulses of current to RS232 level voltages between an air-conditioner and a computer is described. The conversion circuit is able to troubleshoot the communication signals between the indoor unit and outdoor unit of an air-conditioner.

Abstract: A circuit for converting data of a signal line in the form of logical pulses of current to RS232 level voltages between an air-conditioner and a computer is described. The conversion circuit is able to troubleshoot the communication signals between the indoor unit and outdoor unit of an air-conditioner.

Abstract: An apparatus for controlling an air distribution system by controlling the speed of a motor associated with a blower to maintain a rate of air flow in the system at substantially a target air flow rate. The apparatus comprises means for controlling a supplied frequency to the motor; means for providing a speed signal representative of the speed of motor; means for providing a frequency signal representative of the supplied frequency from a controller to the motor; means for providing a load signal representative of the load of the motor; means for calculating an air flow rate signal based on the speed signal and the load signal; means for controlling a supplied frequency in response to the target air flow rate signal and the calculated air flow rate signal. The apparatus can apply three different types of algorithm for controlling and compensating the motor.

Abstract: A communication apparatus for converting signal between differential interchange circuit and multiple devices having input and output terminals comprising: a timer for detecting logic level at idle state; a flip-flop having at least one output terminals for switching a signal from one to the other by means of an external signal; and at least one or more of logic gates for inverting said external signal from said circuit.

Abstract: A power factor correction circuit having an input current for reducing the distortion and harmonics generated in a power line feeding power supply comprising: a control switch (IGBT) for producing a control switch current and virtual short circuit; a load for acting as power demand from a load and producing a load current; and one or more of resistors for measuring current within said circuit.

Abstract: An apparatus for controlling an air distribution system for maintaining a rate of air flow in the system at substantially the target air flow rate, wherein the apparatus comprises: means for detecting current speed and torque of said motor and generating said current speed signal and torque signal after detection; means for receiving current speed signal and torque signal and calculating current air flow rate in the air distribution system wherein the calculated current air flow rate is being compared to the target speed signal of the air flow rate and the current air flow rate is adjusted according to the target speed signal of the air flow by generating a control signal; and means for controlling the motor speed in response to the control signal for maintaining the rate of air flow in the system at substantially the target speed signal of the airflow rate.