摘要:
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.
摘要:
An automatic clothes washing appliance of the type incorporating a stationary tub, a clothes receiving basket movably supported in the tub, a spray system for distributing fill water over the articles received in the basket, and a drive motor which selectively drives the basket for wash and spin cycle operation. The control system for the appliance includes an arrangement for detecting the existence of an oversuds condition in the tub and basket which is operative upon detection of an oversuds condition to interrupt appliance operation and initiate a corrective cycle which includes actuation of the spray system to spray water over the clothes in the basket. Upon completion of the corrective cycle, normal appliance operation is resumed from the point of interruption. In accordance with one aspect of the invention, the detection arrangement monitors motor speed to detect a change indicative of an increased load on the motor. The corrective cycle is initiated upon detection of a decrease in motor speed of a predetermined magnitude relative to an automatically adjusted reference speed.
摘要:
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. If a pulse rate different from the corresponding to the normal power supply frequency is detected when the appliance is operating in its start-up mode, signifying the test device is in its first state, the self-diagnostic test mode is initiated, otherwise operation in the normal mode is initiated.
摘要:
An automatic clothes washing appliance of the vertical axis type for a clothes washing operation having a plurality of cycles including wash and spin cycles incorporating a tub, a clothes receiving basket movably supported in the tub, means for distributing fill water to the articles received in the basket, and a drive motor which selectively drives the basket for a wash mode and a spin mode. The control system for the appliance includes an arrangement for detecting the existence of a basket out-of-balance condition in the spin mode and initiates a rebalance operation which includes means to measure the basket rotational speed during the spin mode and means responsive to detection of basket rotational speed being less than a predetermined normal balanced basket rotational speed at a predetermined time in the spin cycle to interrupt the spin cycle and to actuate a rebalance cycle and thereafter to resume the spin cycle.
摘要:
A control arrangement for a reversible alternating current split phase induction motor of the type having a start winding electrically connected in parallel with a run winding, which controls the duty cycle of current in the start winding to selectively initiate rotation of the motor in the desired direction.In one form of the invention, a thyristor switching device is connected in series with the start winding to phase control the start winding current. An electronic controller triggers the thyristor into conduction at a first firing angle to initiate motor rotation in one direction and at a second firing angle to initiate motor rotation in the other direction. The first firing angle is less than 45.degree. and preferably in the range of 25.degree.-45.degree. relative to the supply voltage signal and the second firing angle is preferably in the range of 90.degree.-135.degree. relative to the supply voltage signal.In another form of the invention, the control arrangement additionally includes a monitoring circuit which monitors the phase angle between line voltage and run winding current. The controller is responsive to the monitoring circuit to inhibit thyristor trigger signals to the start winding thyristor when a predetermined relationship exists between the phase angle and a reference value, thereby effectively switching the start winding out of the circuit when the motor gets up to speed.
摘要:
A method and apparatus for progressively cutting, piercing, bending, stacking, and interlocking lamination assemblies from a strip of laminate. The stacked laminations are mechanically interlocked with a staple-style interlock that secures all the laminations in the stack together. All the steps in the process of forming, stacking and interlocking are done within the tool and die assembly, eliminating the need for additional equipment to stack and interlock assemblies.
摘要:
A dynamoelectric machine having a permanent magnet rotor construction which contains the permanent magnets while inhibiting flux leakage. The invention further permits rapid, substantially conventional manufacturing techniques to be employed in the formation of rotor laminations used to build the rotors. Flux leakage and formation of reluctance components are inhibited either within the individual rotor laminations or along the length of the rotor by interleaving rotor lamination of different types. The rotor may further be constructed to absorb vibrations within the rotor core and insulate the rotor shaft. The rotor may be still further be constructed for counterbalancing the unbalance of a shaft on which the rotor is mounted.
摘要:
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.
摘要:
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. The protective circuit also includes a comparator for detecting the DC link voltage and for generating an overvoltage signal representative of an overvoltage condition in the DC link circuit and a power switch for shunting current in the DC link circuit across the link capacitor thereby dissipating the overvoltage condition.
摘要:
An electric motor having a snap-together construction without the use of separate fasterners. 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.