Abstract: An electric motor having a snap-together construction without the use of separate fasteners. The construction of the motor removes additive tolerances for a more accurate assembly. The motor is capable of programming and testing after final assembly and can be non-destructively disassembled for repair or modification. The motor is constructed to inhibit the ready entry of water into the motor housing and to limit the effect of any water which manages to enter the housing.

Abstract: An electric motor having a snap-together construction without the use of separate fasteners. The construction of the motor removes additive tolerances for a more accurate assembly. The motor is capable of programming and testing after final assembly and can be non-destructively disassembled for repair or modification. The motor is constructed to inhibit the ready entry of water into the motor housing and to limit the effect of any water which manages to enter the housing.

Abstract: A refrigeration system to be driven by an electrical power source. A compressor mechanism in a hermetically sealed compressor housing circulates a refrigerant located within the compressor housing through a loop. A motor in the compressor housing and in contact with the refrigerant within the compressor housing is coupled with the compressor mechanism. A power supply line adapted to be connected to the electrical power source has an interior portion passing through and located within the compressor housing. The interior portion is in contact with the refrigerant in the compressor housing. A power switching circuit in the compressor housing and in contact with the refrigerant within the compressor housing connects between the power supply line and the winding for selectively applying electrical power from the electrical power source to a motor winding.

Abstract: A dynamoelectric machine has a stator end cap mounted on a stator core, which attaches a control circuit board directly onto the stator. The end cap has integrally formed fingers which permit snap on connection of the circuit board. Guide pins make certain the circuit board is oriented properly upon connection to the end cap. The end cap also has wire fixtures which hold winding leads of a winding and permit insulation displacement terminals on the circuit board to plug into the winding leads and achieve electrical contact at the same time the circuit board is mounted on the end cap. Hall devices mounted onto the circuit board are guided into pockets formed on teeth of the stator end cap for precise location. The end cap is constructed to shield the winding from contact with the motor shell. In addition, backward curved fans are employed to reduce mechanical noise in the direction of high speed rotation.

Abstract: A motor having an external rotor, or "inside out motor" has a split C arrangement of ferromagnetic members which function as the poles of the electromagnet in the motor. The ferromagnetic members are generally C-shaped and mounted on opposite end caps of the motor. The ferromagnetic members on the opposing end caps are angularly offset from each other. The ferromagnetic members on each end cap are also spaced apart from each other, and receive a portion of the motor windings within them. The motor is constructed for assembly using few or no separate fastening devices to secure the components together. In one embodiment, a bearing core serves as the base on which all parts are assembled.

Abstract: A capacitively powered motor having a power switching circuit adapted to be connected between a power source and its winding for selectively energizing the winding to generate a magnetic field which causes a rotating assembly to rotate. A position sensing circuit provides a position signal representative of the position of the rotating assembly and a commutating circuit controls the power switching circuit to commutate the power switching circuit at a commutating angle and at a substantially constant duty cycle to achieve a desired rotating speed of the rotating assembly. The commutating circuit varies the commutating angle in response to the position signal to maintain the substantially constant rotating speed of the rotating assembly. As result, the efficiency of the motor is varied to maintain the substantially constant rotating speed.

Abstract: A dynamoelectric machine has a stator end cap mounted on a stator core, which attaches a control circuit board directly onto the stator. The end cap has integrally formed fingers which permit snap on connection of the circuit board. Guide pins make certain the circuit board is oriented properly upon connection to the end cap. The end cap also has wire fixtures which hold winding leads of a winding and permit insulation displacement terminals on the circuit board to plug into the winding leads and achieve electrical contact at the same time the circuit board is mounted on the end cap. Hall devices mounted onto the circuit board are guided into pockets formed on teeth of the stator end cap for precise location. The end cap is constructed to shield the winding from contact with the motor shell. In addition, backward curved fans are employed to reduce mechanical noise in the direction of high speed rotation.

Abstract: A motor having a power switching circuit adapted to be connected between a power source and its winding for selectively energizing the winding to generate a magnetic field which causes a rotating assembly to rotate. A position sensing circuit provides a position signal representative of the position of the rotating assembly and a commutating circuit controls the power switching circuit to commutate the power switching circuit at a commutating angle to achieve a desired rotating speed of the rotating assembly. The commutating circuit varies the commutating angle in response to the position signal to maintain the substantially constant rotating speed of the rotating assembly. As result, the efficiency of the motor is varied to maintain the substantially constant rotating speed.

Abstract: A motor system having a stationary assembly including a winding and a rotatable assembly in magnetic coupling relation to the stationary assembly. A power supply link having upper and lower rails supplied by a power supply provides power to the motor winding. The power supply link has power switches responsive to a motor control signal for selectively connecting the rails to the winding to energize the winding with a motor current whereby an electromagnetic field is produced for rotating the rotatable assembly. The power switches include a set of upper power switches and a set of lower power switches. Each of the power switches has a conducting state and a nonconducting state. The system includes a disable circuit for selectively generating a disable signal and a control circuit for generating the motor control signal to control the power switches.

Abstract: A vibration isolating mounting system for an electric motor comprising includes a plurality of mounting arms formed from rod stock and each having one segment extending generally parallel to an axis of the motor and another segment extending generally perpendicular to the motor axis. The one is swaged at an end to create a pair of spaced protrusions. A plurality of circumferentially spaced retainers are mounted on the motor and adapted for passage of the end of the one segment when the arm is rotationally positioned to align the spaced protrusions in a first orientation. After insertion of the one end, the arm is rotated to align the protrusions away from the first orientation such that the protrusions engage the retainer and prevent axial motion of the one segment. In another form, a second retainer is spaced from the first retainer and the one end of each arm passes through both retainers to provide additional support between the arm and motor.

Abstract: An apparatus for use with a refrigeration system including a compressor for compressing a working fluid evaporated in an evaporator and condensed in a condenser. A control circuit initiates operation of a refrigeration cycle and initiates a defrost cycle in response to a defrost enable signal. The apparatus drives an air moving assembly moving air over the evaporator. A motor including a rotatable assembly is in driving relation to the air moving assembly. An energizing circuit selectively energizes the motor in response to the control circuit. A sensing circuit generates a speed/torque signal representative of a speed or a torque of the motor. A defrost initiating circuit generates the defrost enable signal when the speed/torque signal indicates that the speed is greater than a predetermined speed or the torque is greater than a predetermined torque.

Abstract: Systems and methods for controlling a draft inducer for use with a furnace. The draft inducer includes a fan for inducing a draft in the furnace combustion chamber that causes a pressure drop across a heat exchanger assembly for moving exhaust combustion chamber gases. The heat exchanger assembly has a plurality of heat exchanger elements which determine furnace capacity wherein the pressure drop across the heat exchanger assembly is affected by the furnace capacity. A motor drives the fan in response to a motor control signal and a memory stores information defining a relationship between motor speed, motor torque and parameters defining motor operation. A processor determines the speed and torque of the motor and retrieves from the memory the parameters corresponding to the determined motor speed and motor torque. The processor is responsive to the retrieved parameters for defining at least one set of speed/torque curves corresponding to a desired pressure drop across the heat exchanger assembly.

Abstract: Draft inducer systems and methods for use with a furnace. A motor drives a fan in response to a motor control signal for inducing a draft which is a function of motor speed and motor torque. A processor defines a speed/torque operating curve having a minimum desired speed and a maximum desired speed between which the speed/torque operating curve is coincident with a pressure curve corresponding to a desired pressure drop across the furnace heat exchanger assembly caused by the draft induced by the fan. The speed/torque operating curve, for a given speed above the maximum desired speed, defines a torque less than the torque defined by the pressure curve for the given speed.

Abstract: Systems and methods for controlling a draft inducer for use with a furnace. The draft inducer includes a motor for driving a fan for inducing a draft in the furnace that causes a pressure drop across the heat exchanger of the furnace. A memory stores information including a table of predefined speed/torque values for defining a set of speed/torque curves for operating the motor. A pressure switch provides a pressure signal representative of a reference pressure across the heat exchanger and a processor determines the speed and torque of the motor when the pressure drop corresponds to the reference pressure. In response to the determined motor speed and motor torque, the processor retrieves a parameter defining at least one delta value from the memory. The processor adapts the predefined speed/torque values as a function of the delta value thereby to define the speed/torque curves corresponding to a desired pressure drop.

Abstract: Systems and methods for controlling a draft inducer for use with a furnace. The draft inducer includes a fan for moving combustion chamber gases for inducing a draft in the furnace combustion chamber that causes a pressure drop across a heat exchanger. The density of the gases flowing across the heat exchanger and the fan differs from a first operating state of the furnace to a second operating state of the furnace. A motor drives the fan in response to a motor control signal so that different motor speeds result as a function of the density of the gases flowing across the fan. A control circuit generates the motor control signal as a function of a first set of speed/torque curves until a speed signal indicates that the motor has reached a predetermined speed. After the speed signal indicates that the motor has reached the predetermined speed, the control circuit generates the motor control signal as a function of a second set of speed/torque curves.

Abstract: A system and methods to provide a desired operating area for a motor driving a fan for inducing a draft in a vent of a heating, ventilating and air conditioning system. The motor includes a stationary assembly and a rotatable assembly. The stationary assembly includes windings adapted to be energized in at least one preselected sequence. The rotatable assembly is in magnetic coupling relation to the stationary assembly and in driving relation to the fan. The system includes a commutating circuit responsive to a pressure signal representative of a minimum air pressure in the vent and a tachometer signal representative of the speed of the motor for controlling power switching devices. The power switching devices selectively connect a power supply to the windings to provide a motor current to the windings in the preselected sequence to produce an electromagnetic field for rotating the rotatable assembly at a motor operating speed.

Abstract: A protective DC link circuit connecting a motor to a power supply. The motor has a stationary assembly and a rotatable assembly in magnetic coupling relation thereto and includes windings adapted to be commutated in at least one preselected sequence. The motor also has power switches for selectively providing power to the windings in the preselected sequence by switching the power supply in connection with the windings whereby an electromagnetic field is produced for rotating the rotatable assembly. The DC link circuit connects the power supply to the power switches. The DC link circuit includes a link capacitor connected in parallel with the power supply wherein a voltage across the link capacitor defines a DC link voltage.

Abstract: A control circuit for a motor driving a fan for inducing a draft in the exhaust of a heating, ventilating and air conditioning (HVAC) system. The control circuit may be used in conjunction with either a variable pressure sensor or one or two discrete pressure sensors. A controller receives information defining the pressure set point. The information may be from a switched register or low or high pressure input signals. The motor speed/torque is increased until the pressure set point is reached.

Abstract: A test initiating device connectible to the power cord of an electronically controlled appliance for initiating appliance operation in either a normal operating mode or a self-diagnostic test mode. When so connected the test device is selectively switchable between a first state in which the device is operative to suppress power signal half cycles of one polarity and a second state in which the power signal from the power supply is coupled to the appliance control circuit essentially unchanged. The appliance control circuit includes circuitry operative to generate interrupt pulses marking the pulsations of the power signal applied to the control circuit. Logic circuitry monitors the pulse rate of these interrupt pulses.

Abstract: A protective circuit arrangement for sheathed heating elements which interrupts ground fault conditions by effectively decoupling the power line from the heating element regardless of the polarity of the power supply connections. A fusible link couples each side of the heating element to the power supply. A normally open switch responsive to current in the ground path switches a relatively low resistance shunt current path across the heating element when the ground current exceeds a predetermined threshold level. Closure of the shunt path enables sufficient current to flow in the power supply lines to actuate the fusible links. Circuit parameters are selected such that the current in the fusible link coupled to the hot power line is sufficiently greater than that in the fusible link coupled to the neutral line to cause the hot power line fusible link to be actuated first, thereby interrupting the fault condition and decoupling the hot power line from the heating element.