Abstract: A source of kine supply voltage is coupled to a video amplifier that drives a cathode of a cathode ray tube of a projection television receiver via a self biasing diode. When, due to, for example, a fault condition, the kine supply voltage is lost, the self biasing diode decouples the cathode of the cathode ray tube from a supply return terminal of an ultor supply voltage to form a high impedance, low capacitance at the cathode of the cathode ray tube. A beam current develops a self biasing voltage at the cathode of the cathode ray tube that substantially reduces the beam current to provide protection against a damage to a screen of the cathode ray tube.

Abstract: A voltage at a control grid of a cathode ray tube is generated at a blanking level to provide beam current blanking when horizontal deflection loss occurs. The control grid voltage at the blanking level is developed in a capacitor prior to an instant in which the horizontal deflection loss occurs. When the capacitor voltage is applied to the control grid to provide the blanking level, the capacitor is discharged slowly. To maintain the capacitor charged, prior to such instant when horizontal deflection is lost, the capacitor voltage is not applied to the control grid as long as the horizontal deflection is normal, regardless of whether vertical deflection loss occurs. Either horizontal deflection loss or vertical deflection loss will disable a video driver stage that controls the cathode of the cathode ray tube for providing additional beam current blanking capability.

Abstract: A standby/run power supply and control circuit for a television apparatus comprises first and second sources of DC voltage, one of which is unswitched and available during a standby mode of operation and the other one of which is switched and available only during a run mode operation. A voltage regulator has an input coupled to both DC sources and has an output for supplying a regulated DC voltage at a first power level during the standby mode and at a second power level during the run mode. A first control circuit, such as a CMOS integrated circuit, is coupled to the regulated voltage output and operable in both the standby and run modes. A second control circuit, such as a second CMOS integrated circuit, is interconnected with the first control circuit, for example by a common control bus. The second control circuit is also coupled to the regulated voltage output, but is operable only during the run mode.

Abstract: A method of teaching a student and using a computer game teaching system, a computer game and educational information contained in one or more tutorial modules. A plurality of questions contained in the tutorial module are presented to the student at pause points in the game, the scoring algorithm for the game is modified as a result of positive responses to the questions to permit higher probability of scoring in the game. The student's responses to the questions are stored in a scores database which is transmitted for analysis, at a central location which analyzes the responses from many students and prepares a report for transmittal to a parent or teacher to guide the student's further education.

Abstract: To produce a cathode voltage of a cathode ray tube that provides black level compensation, a secondary winding of a flyback transformer is coupled in series with a resistor, a capacitor and a rectifying diode. During flyback, a voltage pulse is developed across the capacitor at a magnitude that is increases when the average value of the beam current increases. The voltage pulse causes the cathode voltage to first decrease when the beam current increases.

Abstract: A parabola generator for geometric correction of a television raster, comprises: a resettable circuit for generating a repetitive ramp signal and a resettable integrator for generating a repetitive parabola signal from said repetitive ramp signal. A first resetting circuit initializes the ramp circuit at a frequency related to a scanning frequency. An auxiliary resetting circuit initializes the integrator prior to integrating each repetitive ramp. The auxiliary resetting circuit minimizes timing errors from variations of the ramp signal due to transient conditions. In one embodiment, the scanning period is a horizontal scanning period and the ramp and parabola circuits are reset at the end of each horizontal scanning interval. In this case, the first and auxiliary resetting circuits are responsive to horizontal retrace pulses, for example the leading edges of the horizontal retrace pulses. A further circuit modulates the periodically reset parabolic signal at a vertical scanning rate.

Abstract: An arrangement that compensates for a tendency in a raster width of a display screen of a video display or television to increase when a variation in a beam current occurs, decreases an amplitude of a deflection current to decrease in a nonlinear manner as a function of an increase in the beam current. At a low beam current, a given increase in the beam current produces a decrease in the amplitude of the deflection current that is substantially greater than caused by the same increase at a high beam current.

Abstract: Three vertical deflection windings of corresponding three deflection yokes that are mounted on three cathode ray tubes of a projection video are coupled in series through corresponding three connector pairs. Three horizontal deflection windings of the corresponding three deflection yokes are coupled in parallel through the corresponding three connector pairs. When any of the three connector pairs is left disengaged, a disabling signal that is indicative of a loss of a vertical deflection current in the series coupled vertical deflection windings is generated. The disabling signal is coupled to a corresponding video driver of each of the cathode ray tubes for providing beam current blanking to protect the screens of the tubes against a screen burn damage.

Abstract: A color television receiver includes a comb filter having luminance and chrominance outputs coupled to respective inputs of a display processor. A signal source provides composite and non-composite color video signals for display. A switching circuit having a first operating mode for coupling the composite video signal to an input of the comb filter for enabling display thereof by said display processor. The switching circuit has a second operating mode for coupling the luminance component of the non-composite video signal to the input of the comb filter and for concurrently coupling the chrominance component of the non-composite video signal to the chrominance output of the comb filter for facilitating display of the non-composite video signal by said display processor.

Abstract: A disc player is provided that has disposed in it an insertion opening through which discs having different diameters can be inserted. A disc driving mechanism, including a turntable, is located behind the insertion opening, and there is disposed a slideably mounted stopping means in the disc insertion path behind the turntable for guiding into position over the turntable a disc of either small or large diameter.

Abstract: A detector for vertical synchronizing pulses comprises a nonwrapping up/down counter and a comparator. The counter level samples a composite synchronizing signal at a sampling rate. The counter has a numerical output which increases responsive to detection of said level during a sample interval and decreases responsive to nondetection of said level during a sample interval. The comparator generates a vertical sync detection pulse when the numerical output of the counter is greater than a reference value. In order to provide hysteresis, the numerical value os alternately one of first and second numerical reference counts, the first reference count being greater than the second reference count. The comparator initiates the vertical sync detection pulse when the numerical output of the counter rises above the first reference count and terminates the vertical sync detection pulse when the numerical output of the counter falls falls below the second reference count.

Abstract: In apparatus including a number of functional elements coupled to a common supply bus, certain of the elements may draw time varying supply current related to signal being processed. Supply current compensation circuitry responsive to signal processed by such elements is included to draw equal and opposite time varying supply current to maintain the total supply current constant and thereby to limit localized supply potentials variation. Exemplary compensation circuitry for an amplifier includes a transistor coupled between the supply busses and controlled by signal potential from the amplifier to draw supply current proportional to the signal applied to the amplifier, which supply current is opposite in phase to supply current drawn by the amplifier.

Abstract: Disclosed is a component carrier adapted for mounting components on curved surfaces. The carrier comprises a rigid base member having a top surface adapted for supporting a component and a bottom surface curved to mount flush to a complementary curved support surface.

Abstract: The optical transceiver includes a headset antenna assembly, which is adapted to be worn on the head of the user, and which is connected electrically by a cable to a transceiver unit adapted to be worn on the belt of the user. The headset antenna assembly includes a set of alternating light emitting diodes and photosensitive diodes which are disposed on the antenna assembly to transmit and receive optical signals about a substantially 360 degree radial axis. The light emitting diodes are inclined upwardly from a horizontal plane to help avoid obstructions. Baffles are disposed between the diodes to reduce feedback interface, and a circuit in the transceiver unit discriminates against background light.

Abstract: A patient monitoring system includes a plurality of leads adapted to be coupled to a patient for generating individual ECG data voltage signals. A switching matrix couples the leads to a plurality of differential circuits for coupling selected pairs of the ECG voltage signals to each of the differential circuits for generating differential ECG vector signals functionally related to the difference between selected pairs of the ECG voltage signals. A microprocessor is coupled to the leads and to the switching matrix and is operative to reset the switching matrix to uncouple one or more first leads from the differential circuits and for coupling one or more different ones of the ECG voltage signals to differential circuit formerly coupled to receive the voltage signal from the one or more first leads.

Abstract: A fluid container assembly including one large, relatively narrow container having an orthogonally shaped recess or depression in a wall portion thereof, and two small fluid containers nested within the recess. The recess has means therein engagable with mating means on each of the small containers for retaining the small containers within the recess against accidental dislodgement and so that the external walls of the containers are flush. Each fluid container is provided with a tamper indicating insert such that tampering renders difficult withdrawing fluid.

Abstract: A patient monitoring system includes a plurality of leads adapted to be coupled to a patient for generating individual ECG data voltage signals. A switching matrix couples the leads to a plurality of differential circuits for coupling selected pairs of the ECG voltage signals to each of the differential circuits for generating differential ECG vector signals functionally related to the difference between selected pairs of the ECG voltage signals. A microprocessor is coupled to the leads and to the switching matrix and is operative to reset the switching matrix to uncouple one or more first leads from the differential circuits and for coupling one or more different ones of the ECG voltage signals to differential circuit formerly coupled to receive the voltage signal from the one or more first leads.

Abstract: An apparatus is disclosed for maintaining accurate control of the maximum duty cycle generated by pulse width modulators. The output signal of a pulse width modulation comparator is averaged and compared to a reference value. This reference value is proportional to the peak value of the comparator's output voltage. A closed loop circuit continually adjusts the duty cycle so the difference between the reference value and the average comparator output is nulled thereby providing an accurate maximum duty cycle output.

Abstract: A disc-type motor characterized by increased efficiency includes first and second parallel spaced stator members made of magnetic material in fixed relation, each of the stator members having a flat circular shape and an even plurality of pie-shaped permanent-magnet poles thereon, illustratively eight in number. The facing poles on the stator members have opposite polarities. The motor further includes a disc-like rotor made of a non-conducting material rotatably mounted between the two stator members. Conducting wires are wound in a non-overlapping (single-layer) flat spiral configuration to form a number of coils equal to twice the number of poles per stator member, half adhered to each face of the rotor disc. Each coil encloses a pie-segmented area about equal to the area of one of the stator poles. On each face of the rotor the coils magnetically oppose one another, and the coils on one face of the disc are angularly offset from the coils on the other face of the disc.