By Dr. Derald D. Cummings, C-COR Electronics, Inc.
The nature of CATV system transients is discussed and the devices used for system protection are evaluated and compared. Methods of employing protective devices to the best advantage of the system are discussed and a multi level field proven protection scheme is presented.
The causes of system outages are explored and the impact of protection schemes on fusing and related outage problems is discussed. It is shown that proper fusing together with judicious protective device application can eliminate all but the most catastrophic outages, excepting, of course, loss of primary power. For outage protection with loss of primary power the various means of standby powering are explored and a new concept in standby power source implementation is presented.