摘要:
A power supply for use in an accelerated weathering test apparatus can ignite the lamp without using a separate igniter and control both the xenon lamp radiated spectrum and its intensity in order to fully simulate the sun's daily cycle, improve the ultraviolet output, reduce the infrared radiation, and compensate for the xenon lamp aging.
摘要:
An encryption arrangement for multiple encryption of television programs. A system according to embodiments of the present invention multiple encrypts only a portion of the data required for full presentation of a television program to permit coexistence of multiple conditional access encryption systems associated with multiple manufacturer's set-top boxes within a single system. In one embodiment, only audio data are encrypted leaving video in the clear. By only encrypting a portion of the program, dramatically less bandwidth is consumed than the alternative of multiple encryption of all program data, thus permitting a larger number of programs to be carried over the same bandwidth while permitting coexistence of multiple conditional access systems in a single cable television system.