Accession Number : AD0845340

Title :   Diode Control Research.

Descriptive Note : Quarterly technical progress rept. no. 8, 1 May-1 Jun 68,

Corporate Author : MALLORY (P R) AND CO INC BURLINGTON MA LAB FOR PHYSICAL SCIENCE

Personal Author(s) : Ball, James V.

Report Date : JUN 1968

Pagination or Media Count : 34

Abstract : The end-of-charge voltage of the silver-cadmium spacecraft cells is not in the range of obtainable silicon stabistor voltages. It was found, however, that one seven-junction silicon stabistor could act as a temperature-compensated voltage sensor for three silver-cadmium cells, allowing maintenance of cell charge during continuous 120-minute cycling at 75 percent depth of discharge. Large batteries can be formed from such three-cell, stabistor controlled groups. Burn-in and thermal cycle tests of epoxy stabistors show that, despite a slight initial shift of stabistor voltage with use, good stability is maintained for extended periods. Stabistor controlled sealed silver-zinc cells were cycled to the end of their usable life at 75 percent depth of discharge (90-minute cycle) without excessive or destructive pressure buildup, as demonstrated by the lack of cell case and encapsulation distortion during the test. The sole purpose of the encapsulation was to ensure adequate sealing. (Author)

Descriptors :   (*ALKALINE BATTERIES, PERFORMANCE(ENGINEERING)), SPACEBORNE, SILVER, CADMIUM, SEMICONDUCTOR DIODES, SILICON, CONTROL SYSTEMS, VOLTAGE, DETECTORS, HEAT SINKS, ELECTRIC DISCHARGES, MAINTENANCE.

Subject Categories : Electrochemical Energy Storage

Distribution Statement : APPROVED FOR PUBLIC RELEASE