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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A microcontroller based control system for an automatic clothes dryer of the type having dry cycle time-drum outlet air temperature function which reflects an initial warm up period of relatively rapidly rising temperature; followed by a period in which the outlet air temperature remains relatively constant at the plateau temperature; followed by a period of relatively rapidly increasing outlet air temperature. The control system maintains a substantially constant drum inlet air temperature and senses outlet air temperature, initiating termination of the dry cycle as a function of the integral of dry cycle time as a function of outlet air temperature.

Abstract: A safety power cutoff arrangement is disclosed for appliances which utilize membrane panel switches on their control panels causing electrical power to the appliance to be shut off in the event of damage to the control panel. The safety cutoff arrangement comprises a conductive track pattern formed over the outermost circuit sheet forming the membrane switch and interrupter circuitry which requires the continuity of the conductive track pattern to be maintained for electrical power to be continued to be supplied to the appliance circuitry. In the event of damage to the control panel, breaking of any segment of the conductive track pattern results in the interrupt safety circuit cutting off power to the appliance.

Abstract: An electrical circuit provides continuous or intermittent energization of an electric apparatus, such as a magnetron that generates microwave energy for use in in a microwave oven or the like. When continuously energized the magnetron produces a maximum power output, for example, to cook a food load in the microwave oven; and when intermittently energized the magnetron produces a lower average microwave energy power level to cook food at a relatively slower rate and/or to defrost frozen food efficiently without cooking the outer surface thereof, as the brief off time during each complete cycle of the intermittently energized magnetron allows some temperature equilibration through the food product. The electrical circuit includes a cycling switch mechanism for such intermittent energization of the magnetron and a mechanical lock-out for biasing the switch mechanism to supply continuous energy to the magnetron.