Electrochemical coulometer and method of forming same Patent
Alkaline-type coulometer cell for primary charge control in secondary battery recharge circuits
Stroup, E. R.↗
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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Solar bus regulator and battery charger for IMP's H, I, and J
Interplanetary Monitoring Probe (IMP) spacecrafts H, I, and J utilize a direct energy transfer (DET) type of power system operating from a solar array source. A shunt type of regulator prevents the bus voltage from exceeding a preset voltage level. The power system utilizes a single differential amplifier with dual outputs to control the battery charge/shunt regulator and the discharge regulator. A two-voltage level, current limited, series charger and a current sensor control battery state of charge of the silver-cadmium battery pack. Premature termination of the battery charge is prevented by a power available gate that also initiates charge current to the battery upon availability of excess power.
Paulkovich, J.↗
The Atmosphere Explorer power subsystem
The design and operation of the power subsystem for the Atmospheric Explorer spacecraft are discussed. The additional functional redundancy which was added in several component areas to improve the overall subsystem reliability is analyzed. The battery charging technique has been modified to include third electrode overcharge control. The automatic removal of all battery charge is provided to correct abnormally high battery voltages. An undervoltage detector has been added which removes all nonessential spacecraft loads when the battery voltage falls below a given level. All automatic functions can be over-ridden by ground command.
Obenschain, A.↗
Microprocessor control of photovoltaic systems
The present low power CMOS microprocessor controller for photovoltaic power systems possesses three programs, which are respectively intended for (1) conventional battery-charging systems with state-of-charge estimation and sequential shedding of subarrays and loads, (2) maximum power-controlled battery-charging systems, and (3) variable speed dc motor drives. Attention is presently given to the development of this terrestrial equipment for spacecraft use.
Millner, A. R.↗
Performance Comparison Between NiH2 Dry Sinter and Slurry Electrode Cells
The electrical and thermal performance of dry sinter and slurry process electrode cells manufactured for the Hubble Space Telescope (HST) batteries have been characterized for a matrix of operating conditions over the temperature range from 14 to 86 F at various charge control levels. The dry sinter process electrode cells tested are similar to the onboard HST NiH2 cells. The slurry process electrode cells were developed to be less susceptible to electrode expansion and impedance changes with life. Both cell types were impregnated by the aqueous electrochemical process. Test conditions included standard capacity tests and electrical cycling using 96-minute cycling regimens incorporating gr depth-of-discharge (DOD) cycles. The dry sinter process electrodes have higher operating capacities to 1.20V/cell, but both electrode types have similar heat dissipation for the conditions tested. The results of the testing included cyclic heat generation during a typical 96-minute cycle, operating capacity data vs. cutoff voltage to generate a temperature-compensated voltage curve, and voltage characteristics suitable to develop a voltage prediction model. Analysis of data shows differences in the discharge voltage plateaus operating conditions evaluated. This is the basis for recommended changes in the battery charge control.
Armantrout, J. D.↗
Nickel-hydrogen LEO cycling at 20 percent - 50 percent DOD
The test setup consists of four major elements: the programmable power supplies and load banks, the data acquisition and control system control computer, and the NiH2 specimen test cells. A simplified block diagram of the test setup is shown. The test setup provides complete battery isolation should a fault occur, and fusing as necessary to protect the battery cells and other equipment. Front panel switches provide for power supply configuration and battery isolation. Front panel meters provide continuous real-time visual monitoring of the voltage and current for each pack of cells. A strip chart recorder provides a hard copy of the voltage and current profiles for each of the packs. The test operates continuously with minimal human interface, except during special tests. The two power supplies are controlled by resistance programming. A bank of resistors and relays was built which can be switched by the control computer to provide control over the charge current to the batteries. The load banks are controlled by the 3497A. The 3497A is equipped with a 0.5 volt programmable power supply which is used to voltage program the load banks. A Hewlett-Packard Vectra 9000 running an HP Basic program is used as the control computer to remotely instruct the 3497A (data acquisition and control) to scan the data channels and retrieve test data. The program then reads, calculates, and stores the data. If an anomaly occurs, the program will disconnect the cells and shut down the test to avoid damage to the cells or equipment.
Lowery, John E.↗
Recharge unit provides for optimum recharging of battery cells
Percent recharge unit permits each cell of a rechargeable battery to be charged to a preset capacity of the cell. The unit automatically monitors and controls a rechargeable battery subjected to charge-discharge cycling tests.
Baer, D.↗
Nickel Cadmium Charge Control Concepts
The design and testing of charge control concepts for several power systems is presented. The design of the CRAM charge control system for the SAS satellites and the design of the battery charge regulator for the AMPTE satellites is reviewed. Another charge control concept examined is for the OPEN program and its use of a microprocessor. The use of the voltage limiter is also discussed.
Sullivan, R. M.↗
Mars Rover 2003 Battery Charger
The Jet Propulsion Labortory Mars Exploration Program Office is currently planning a series of execiting missions to the Red Planet.
Charge↗
The 100 ampere-hour nickel cadmium battery development program, volume 1
A program to develop a long-life, reliable and safe 100 ampere-hour sealed nickel-cadmium cell and battery module with ancillary charge control and automated test equipment to fulfill the requirements of a large Manned Orbital Space Station which uses Solar Arrays as its prime source for 25 kW of electrical power was conducted. A sealed 100 ampere-hour cell with long life potential and a replaceable, space maintainable battery module has been developed for Manned Space Station applications. The 100 ampere-hour cell has been characterized for initial (early life) anticipated conditions.
Gaston, S.↗
Development of a microprocessor controller for stand-alone photovoltaic power systems
A controller for stand-alone photovoltaic systems has been developed using a low power CMOS microprocessor. It performs battery state of charge estimation, array control, load management, instrumentation, automatic testing, and communications functions. Array control options are sequential subarray switching and maximum power control. A calculator keypad and LCD display provides manual control, fault diagnosis and digital multimeter functions. An RS-232 port provides data logging or remote control capability. A prototype 5 kW unit has been built and tested successfully. The controller is expected to be useful in village photovoltaic power systems, large solar water pumping installations, and other battery management applications.
Millner, A. R.↗
The Pulse Width Modulator ASIC for Deep Space Missions
The Jet Propulsion Laboratory has started the development of a Pulse Width Modulator Application Specific Integrated Circuit (PWMA). This development is leveraging the previous development of the Switch Control ASIC (SCA). The purpose of the development is to provide the control for a selected range of power converter topologies and to meet the stringent environmental requirements of deep space missions. The PWMA will include several power control functions that are not normally included on the off-the-shelf components available today. One key functional requirement is the ability to implement an N + K redundant power converter with the ability to control the charging of a battery. Other applications will be the typical point of load isolated and non-isolated power converters. The purpose the development is not only to provide a much needed flight part, but also to accelerate the engineering process by using a standard cell library from previous ASIC developments. Under previous developments with Boeing and Lockheed Martin, JPL has produced three ASICs. Each ASIC has been implemented by using an analog standard cell library. One such development was the SCA, which is design to provide a floating power switch control. The functional verification of this ASIC has been completed and the cells used have been targeted for the new development of the PWMA. The primary function of the PWMA is to provide the control function of a point of load power converter. The design is an isolated 60 W converter with a 33 V output. In architecting the design, several functions were left up to the power converter design in order to make the ASIC more generic. The ASIC can be used for several power converter topologies and power levels. Some additional features have been added to the ASIC to provide the interfaces for multi-phase topologies and battery control functions. An N+K fault tolerant strategy has been implemented in order to provide the battery control functions. The PWMA has been developed to provide an ASIC with several functions not normally available in the off the shelf controllers. These functions have been added to enable the power converter designers to achieve fault tolerant designs and battery control functions.
Pulse Width Modulator Application Specific Integra↗
Nickel-cadmium battery reconditioner
Automatic device for recharging of nickel-cadmium battery
NICKEL-CADMIUM BATTERY↗
Percent recharge unit Final report
Percent recharge unit for automatically monitoring and controlling rechargeable batteries during charge-discharge cycling tests
Source record↗
Automatic Weather Station (AWS) Lidar
An autonomous, low-power atmospheric lidar instrument is being developed at NASA Goddard Space Flight Center. This compact, portable lidar will operate continuously in a temperature controlled enclosure, charge its own batteries through a combination of a small rugged wind generator and solar panels, and transmit its data from remote locations to ground stations via satellite. A network of these instruments will be established by co-locating them at remote Automatic Weather Station (AWS) sites in Antarctica under the auspices of the National Science Foundation (NSF). The NSF Office of Polar Programs provides support to place the weather stations in remote areas of Antarctica in support of meteorological research and operations. The AWS meteorological data will directly benefit the analysis of the lidar data while a network of ground based atmospheric lidar will provide knowledge regarding the temporal evolution and spatial extent of Type la polar stratospheric clouds (PSC). These clouds play a crucial role in the annual austral springtime destruction of stratospheric ozone over Antarctica, i.e. the ozone hole. In addition, the lidar will monitor and record the general atmospheric conditions (transmission and backscatter) of the overlying atmosphere which will benefit the Geoscience Laser Altimeter System (GLAS). Prototype lidar instruments have been deployed to the Amundsen-Scott South Pole Station (1995-96, 2000) and to an Automated Geophysical Observatory site (AGO 1) in January 1999. We report on data acquired with these instruments, instrument performance, and anticipated performance of the AWS Lidar.
Rall, Jonathan A.R.↗
System for energy harvesting and/or generation, storage, and delivery
A device and method for harvesting, generating, storing, and delivering energy to a load, particularly for remote or inaccessible applications. The device preferably comprises one or more energy sources, at least one supercapacitor, at least one rechargeable battery, and a controller. The charging of the energy storage devices and the delivery of power to the load is preferably dynamically varied to maximize efficiency. A low power consumption charge pump circuit is preferably employed to collect power from low power energy sources while also enabling the delivery of higher voltage power to the load. The charging voltage is preferably programmable, enabling one device to be used for a wide range of specific applications.
Trainor, John T.↗
System for energy harvesting and/or generation, storage, and delivery
A device and method for harvesting, generating, storing, and delivering energy to a load, particularly for remote or inaccessible applications. The device preferably comprises one or more energy sources, at least one supercapacitor, at least one rechargeable battery, and a controller. The charging of the energy storage devices and the delivery of power to the load is preferably dynamically varied to maximize efficiency. A low power consumption charge pump circuit is preferably employed to collect power from low power energy sources while also enabling the delivery of higher voltage power to the load. The charging voltage is preferably programmable, enabling one device to be used for a wide range of specific applications.
Trainor, John T.↗
Charge-Control Unit for Testing Lithium-Ion Cells
A charge-control unit was developed as part of a program to validate Li-ion cells packaged together in batteries for aerospace use. The lithium-ion cell charge-control unit will be useful to anyone who performs testing of battery cells for aerospace and non-aerospace uses and to anyone who manufacturers battery test equipment. This technology reduces the quantity of costly power supplies and independent channels that are needed for test programs in which multiple cells are tested. Battery test equipment manufacturers can integrate the technology into their battery test equipment as a method to manage charging of multiple cells in series. The unit manages a complex scheme that is required for charging Li-ion cells electrically connected in series. The unit makes it possible to evaluate cells together as a pack using a single primary test channel, while also making it possible to charge each cell individually. Hence, inherent cell-to-cell variations in a series string of cells can be addressed, and yet the cost of testing is reduced substantially below the cost of testing each cell as a separate entity. The unit consists of electronic circuits and thermal-management devices housed in a common package. It also includes isolated annunciators to signal when the cells are being actively bypassed. These annunciators can be used by external charge managers or can be connected in series to signal that all cells have reached maximum charge. The charge-control circuitry for each cell amounts to regulator circuitry and is powered by that cell, eliminating the need for an external power source or controller. A 110-VAC source of electricity is required to power the thermal-management portion of the unit. A small direct-current source can be used to supply power for an annunciator signal, if desired.
Reid, Concha M.↗