Abstract: An improved watt-hour meter which permits time modulation of the power utilized wherein varying rates can be imposed upon the power user. The improved meter includes a substantially standard type watt-hour meter to which is added circuitry which alters the effective time during which the potential coil of the watt-hour meter is connected in circuit. Inasmuch as the power reading or indication by the meter is a function of the time during which the potential coil is connected in circuit, the effective power reading and, thus the rate structure can be selectively altered in this manner.

Abstract: An automatic ranging device for optical instruments focuses two images of at least a portion of the field of view of the instrument on an array of photosensitive cells. The electronic output of the individual cells is related to the intensity of the light impinging thereon. The electronic output corresponding to the first image is compared with the electronic output corresponding to the second image. The relative location of corresponding portions of the first and second images is a measure of the range to the object which is imaged. Electronic circuitry determines the location at which image coincidence occurs and controls the focus of the optical instrument accordingly.