Abstract: A power control system for a heating element in a cooking appliance having a plurality of possible power settings which provides transient Fast-Heat and Fast-Cool operating modes initiated in response to user-initiated changes to higher or lower appliance power settings, respectively, to reduce the response required for the heating element temperature to reach the operating temperature associated with the new power setting. Approximate heating element temperature information is provided to the control system by an energy counter which is incremented at a rate which is approximately proportional to the rate of increase of the heating element when energized at the power level being implemented. This information is used to prevent initiation of a transient mode if the temperature of the element when the change in setting is made is such that operation in that mode is likely to overshoot the desired new operating temperature.

Abstract: The video disc player includes a selectively-actuated stylus arm lifter. When the player is in the PLAY mode, a forward bias is applied to the lifter electromagnet to cause it to lower the stylus on the record. When the player is disposed in the record LOAD/UNLOAD mode, the lifter is reverse biased to prevent the stylus from being lowered and coming in contact with moving parts during the record load/unload operations.

Abstract: A power control system is disclosed which controls the power output of one or more resistive heating elements in response to operator selected power level settings. Control of power to the elements is accomplished by generating a multi-bit binary word representing a selected power level, each bit being operative to control the application of power to the element during a different control interval. A control word is generated for each element and is updated once during every associated control period, a period comprising a number of intervals equal to the number of heating elements. The heating elements are of a type which draw a relatively high current during a transient heat-up period. The application of power to other elements is inhibited when one of the elements is having power applied thereto during its transient period. Power control for each element is staggered by testing a bit of different positional value in each word during any given interval.

Abstract: A power control system is disclosed for controlling the power output of a resistive heater element in response to operator selected power level settings by varying the rate at which a power pulse of constant duration is applied to the element. The system includes circuitry for generating a control signal representing a selected power output for the element, circuitry for identifying recurring patterns of a binary counter, the patterns recurring at different rates, and a logic arrangement for uniquely associating each of the patterns with a selected power setting. The binary counter and the power pulse control are synchronized with the power supply to trigger a power switching device at or near zero crossovers of the supply.

Abstract: A power control method and system for a cooking appliance using a high inrush current element in which the instantaneous glow from the heater element is utilized to inform the operator of appliance turn-on. The power control includes a logic arrangement for detecting the transition of the appliance from an OFF condition to a selected one of a plurality of power level settings. Prior to energizing the heating element at the selected power level, the control energizes the element for a preselected transient time at a level to produce a visible glow.