Rca Inc.

General Electric Company

Alfred Lynn Baker

Thomas R Payne

Charles B Carroll

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.

Power control for cooking appliance with transient operating modes

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.

Video disc player having stylus protecting apparatus

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.

Power control for appliance using multiple high inrush current elements

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.

Repetition rate power control for appliance using high current inrush

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.

Power control for appliance using high inrush current element

Coupling of pickup arm housing to a slow moving belt for translational motion during record playback is controlled by a play solenoid, while coupling to a fast moving belt for fast forward and reverse motions is controlled by respective forward and reverse solenoids. Player includes manually actuated push button controls for play, forward search, reverse search, pause, reject and power on/off functions. Mechanism actuated switches include a land switch actuated when pickup location is over beginning of recorded information, a travel limit switch actuated when pickup location is beyond ending of recorded information, and a rest switch placed in one switching condition when housing returns to an off-record rest position.

Video disc player mechanism control system

Video disc player is provided with a sync separator which is responsive to output of luminance comb filter after de-emphasis circuit processing. Input to comb filter circuitry is provided by amplitude modulator, responsive to carrier wave oscillations from a voltage controlled oscillator (VCO) and to composite video signals provided by a defect compensation system. The compensation system normally supplies an output directly derived from the player's pickup circuits, but, under defect conditions, substitutes stored video signals. The VCO is a component of a phase locked loop (PLL) arrangement, also including a burst gate for selectively passing color synchronizing information contained in the modulator output. Gating pulses for the burst gate are generated by apparatus responsive to the sync separator output, the generating apparatus including a capacitor charging circuit activated by the trailing edge of a separator output pulse to control gating pulse termination, and a separate capacitor discharging circuit activated by the trailing edge of a separator output pulse to control gating pulse initiation. Also responsive to an output of the sync separator is a keying pulse generator for controlling keyed clamping of the luminance comb filter output, with keying pulse timing determined by differentiated and integrated versions of the separator output.

Sync responsive systems for video disc players

In a video disc player, color picture information recorded in FM carrier form is recovered from the output of player's signal pickup apparatus by an FM demodulator. The FM demodulator includes zero crossing detector circuitry providing a pulse in response to each zero crossing of its signal input, a monostable multivibrator developing a pulse of a substantially fixed width when triggered by an output pulse of the zero crossing detector, and means for low pass filtering the output of the monostable multivibrator to develop signals for application to the player's video signal processing circuits. An output pulse of the zero crossing detector, and an output pulse of the monostable multivibrator subject to a selected delay comprise the inputs to a gate circuit, which develops an output pulse upon any instance of overlapping presence of the respective input pulses to indicate the presence of input signal conditions tending to produce a 'white' defect during picture display. A capacitor is subject to charging toward the turn-on threshold potential of a second gate having its inputs coupled thereto. Resetting of the capacitor charging circuit is effected in response to an output of the monostable multivibrator. The capacitor charging time constant is selected so that the threshold is reached if the recurrence rate of the multivibrator output pulses falls below a reference rate less than twice the lowest intended picture carrier frequency, whereby gate switching indicates the presence of input signal conditions tending to produce a 'black' defect during picture display. The respective defect indications are subject to summing and stretching, and are utilized to control substitution of stored picture information during defect occurrences.

Defect detection and compensation

Video disc player pickup circuit recovers picture information in the form of carrier waves, the instantaneous frequency of which varies over a given deviation range in accordance with the amplitude of composite color video signals, in the course of pickup tracking of successive convolutions of the disc record's groove. Succeeding the innermost groove convolution containing recorded picture information are a plurality of groove convolutions containing an end-of-recording signal comprising unmodulated carrier waves at a given instantaneous frequency within said deviation range. Signal processing circuitry of the video disc player includes a sync separator for separating a deflection synchronizing component from the composite color video signals recovered during playback of the groove convolutions containing picture information. Video disc player also includes a defect detector monitoring carrier frequency departures from the given deviation range, and a squelch signal generator responsive to the output of the defect detector. An end-of-play signal generator responds to the continuance for a given time interval of a simultaneous absence of outputs from sync separator and squelch signal generator by generating an end-of-play signal, which is utilized to terminate record playback efforts and to restore pickup apparatus to a rest position.

End-of-play control system

In a video disc player, a first FM signal recovered from the disc is subject to frequency demodulation to obtain a composite color video signal, and a second FM signal recovered from the disc is also demodulated to obtain an accompanying sound signal. The player includes a defect detector, monitoring the first FM signal to identify carrier frequency departures from the intended deviation range, and switching apparatus for effecting a substitution of stored video signals, in replacement of the output of the video FM detector, when the defect detector identifies such departures. A squelch control signal generator is rendered responsive to an output of the defect detector, and develops a squelch signal when the defect indication persists beyond a predetermined minimum length of time. The squelch signal is employed to inhibit the passage of sound and video signals to player output terminals. The squelch control signal generator is additionally rendered responsive to player apparatus controlling placement of the player stylus in and out of playback position (e.g., controlling lowering/lifting of stylus arm), so that removal of stylus from playback position initiates squelch signal development without need for passage of said predetermined minimum length of time.

Growing community of inventors

Indianapolis, IN, United States of America

Alfred Lynn Baker