Engineering topics
Publications and source records attributed to Hennigan, T. J..
An accelerated test matrix is outlined that includes acceptance, baseline and post-cycling tests, chemical and physical analyses, and the data analysis procedures to be used in determining the feasibility of an accelerated test for sealed, nickel cadmium cells.
Efforts to improve electrochemical systems for space use relate to: (1) improvement of conventional systems; (2) development of fuel cells to practical power systems; and (3) a search for new systems that provide gains in energy density but offer comparable life and performance as conventional systems. Improvements in sealed conventional systems resulted in the areas of materials, charge control methods, cell operations and battery control, and specific process controls required during cell manufacture. Fuel-cell systems have been developed for spacecraft but the use of these power plants is limited. For present and planned flights, nickel-cadmium, silver-zinc, and silver-cadmium systems will be used. Improvements in nickel-cadmium batteries have been applied in medical and commercial areas.
A prototype silver zinc cell is reported for which the electrolyte is being stored in a separate tank; the cell is being activated when additional power is required by collapsing the neoprene bellows container and thus forcing the electrolyte into cell through a plastic connection. A solar array is proposed as main power source for the flow actuator.
Several test programs were carried out to determine the performance and limitations of sealed, silver oxide zinc cells for (1) 24-hr synchronous orbits, (2) orbits that would require a maximum of six cycles per day, and (3) missions to other planets requiring maintenance of maximum capacity for probe operations during planet encounter. The results are summarized to provide power system designers with guidelines bearing on capacity maintenance during cycling, cycle life, charged stand effects, and internal pressure characteristics. The life of zinc silver oxide cells is shown to be limited to one to two years over the temperature range of 0 to 24 C.
Service performance and tests of zinc silver oxide batteries on Explorers 17 and 32
Sampling device, by means of a tapered needle, pierces a sealed container while maintaining the seal and either evacuates or pressurizes the container. This device has many applications in the chemical, preservative and battery-manufacturing industries.
Electrochemical sintering process produces cadmium felt electrodes. Two pieces of cadmium felt are sandwiched around a nickel screen or silver expanded metal grid, held together by mold compression, and electrochemically sinitered by being put through several charge and discharge cycles at low current density.
Battery charging system with cell to cell voltage balance
Apparatus for measuring polymer membrane expansion in electrochemical cells
External source supplies power to electrochemical cells containing internal resistive heater element. Each cell plate is individually contained in its own Pellon bag, enabling the heater element to be arranged in a continuous, parallel circuit.
Sealed electrochemical cell with flexible casing for varying electrolyte level in cell
Epoxy resin sealing device for electrochemical cells in high vacuum environments
Preventing pressure buildup in electrochemical cells by reacting palladium oxide with evolved hydrogen
Circuit prevents battery cell overcharging by detecting and reducing the charging voltage to the open-circuit voltage of the battery when this current falls to a predetermined value. The voltage control depends on the fact that the charging current falls significantly when the battery nears its fully charged state.
Nonmagnetic hermetically sealed battery case made of epoxy resin and woven glass tape for use with electrochemical cells in spacecraft
Solid-state battery charge control system use for nickel-cadmium cells with auxiliary electrodes
Separator materials for secondary silver zinc electrochemical cells for use in space missions
Apparatus consisting of a pressure plate unit, four springs of known spring constant and a micrometer measures the swelling and force exerted by the polymer membranes of alkaline electrochemical cells.