Accession Number : AD0821811

Title :   DIODE CONTROL RESEARCH.

Descriptive Note : Quarterly progress rept. no. 5, 1 Jun-1 Sep 67,

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

Personal Author(s) : Ball, James V. ; Pomerantz, Daniel I.

Report Date : SEP 1967

Pagination or Media Count : 40

Abstract : Tests were conducted on nickel-cadmium sealed spacecraft cells over a temperature range of 0 to 50 C, with charge and discharge rates appropriate to a 75 percent depth-of-discharge, 90 minute cycle. Results of these tests were analyzed to determine a suitable locus of diode knee voltages over the temperature range. Tests in silver-zinc cells indicate that, while the sealed silver-zinc cell voltage characteristic during charge can be utilized for stabistor action, it is difficult to recharge the cell from a 75 percent depth-of-discharge in the 85 minute charge period allowed under the 120 minute cycle. Experimental results supported the conclusions of a theoretical study of stabistor characteristics, making it possible to develop improved design techniques for the preliminary selection of diode and heat sink combinations. A circuit was developed to clamp the reverse voltage of a battery cell at a safe value. Advantages of this circuit are a low cell current drain (less than 2 ma) prior to reversal and all solid state construction. (Author)

Descriptors :   *SEMICONDUCTOR DIODES), (*VOLTAGE REGULATORS, SPACECRAFT COMPONENTS, STORAGE BATTERIES, NICKEL, CADMIUM, SILVER, ZINC, BATTERY CHARGERS, VOLTAGE, CONTROL SYSTEMS, LIMITERS, HEAT SINKS, CIRCUITS.

Subject Categories : Electrical and Electronic Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE