Abstract: A controller for supplying a switching signal to a switched mode power supply, includes a sinusoidal-like wave generator, and circuitry for selectively shifting a dc level in the sinusoidal-like wave whereby a duty cycle of the sinusoidal-like wave at a predetermined threshold level, corresponding to a turn-on level of a power switch in the switched mode power supply, is effectively controlled.

Abstract: A T.V. input source identifying circuit for determining whether a video signal is from a videotape player or a broadcast signal by measuring jitter of vertical synchronization pulses and by measuring noise. The video signal includes a plurality of frames with each frame including a plurality of fields. In one embodiment of the present invention, timing data is generated corresponding to the period of at least one selected field in each of a plurality of selected frames. From this timing data, a maximum number is stored that corresponds to the greatest period and a minimum number is stored that corresponds to the least period of the selected fields. The minimum number is subtracted from the maximum number and the difference is compared to a threshold to determine the type of video signal. In an alternate embodiment, numbers corresponding to fields from successive frames are compared by a subtraction and the difference is compared to a threshold in order to make a decision as to the type of video signal.

Abstract: A T.V. input source identifying circuit for determining whether a video signal is from a videotape player or a broadcast signal by measuring jitter of vertical synchronization pulses and by measuring noise. The video signal includes a plurality of frames with each frame including a plurality of fields. In one embodiment of the present invention, timing data is generated corresponding to the period of at least one selected field in each of a plurality of selected frames. From this timing data, a maximum number is stored that corresponds to the greatest period and a minimum number is stored that corresponds to the least period of the selected fields. The minimum number is subtracted from the maximum number and the difference is compared to a threshold to determine the type of video signal. In an alternate embodiment, numbers corresponding to fields from successive frames are compared by a subtraction and the difference is compared to a threshold in order to make a decision as to the type of video signal.

Abstract: A timing circuit adapted for use in a digital system that includes a raster scanned display device (14) adapted to scan a beam through a series of horizontal scan lines at a rate controlled by a horizontal sync signal. Each horizontal scan line comprises dots that can be individually illuminated. The time required for the beam to horizontally scan one dot is controlled by a dot clock signal. The digital system also includes means for producing row format data indicating the relationship between the horizontal sync signal and the time requried to horizontally scan one character area, and dot per character data indicating the horizontal dot width of one character area. The timing circuit comprises a generator (52) for producing a horizontal reference signal having a frequency corresponding to the desired frequency for the horizontal sync signal, and a phase lock loop for producing the horizontal sync and dot clock signals.

Abstract: Radio frequency energy is applied to a hair at a selected frequency at which that hair impedance to RF energy conduction is substantially lower than at other RF frequencies, to thereby obtain substantially greater energy conduction capability along the hair shaft to the hair papilla.