Browsing by Author "Ginsberg, Samuel I"

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    Open Access
    CO2 body worn logger
    (2016) Leqele, Tumisang; Ginsberg, Samuel I
    Tuberculosis is the second most killing disease in the world, although cure is being provided for the disease in South Africa, prevention becomes the most important part. This calls for a device which can be used to gather statistical data to be used in verifying where TB transmission mostly takes place, and proper conditions be implemented to minimise the TB transmission. Carbon dioxide Body Worn Device (CBWD) is a device which relies on the battery supply for its function. Its function includes gathering the CO2 level, humidity and Temperature as well as the location coordinates with time, and this data stored on the device memory, to allow for downloading, for the user to be able to analyse log data. The device stores its log data on the SD card, and its live results can be viewed using the software or on the device screen. A way to communicate with the device calls for a piece of software which the user can interact with as to issue commands to the device. CBWD software is a piece of software which provides the interface for the user to be able to interact with the device. It provides an easy user menu for the user to download log data, erase log data, synchronise device date and time, and zero the CO2 level. The software also provides the storage for last data downloaded for the device. The system can be improved to integrate with other devices as a control system, for instance on the ventilation system, the device can be integrated to regulate the ventilation rate factors based on the current conditions on the area.
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    Open Access
    An electrical power system for CubeSats
    (2015) Sheard, Benjamin Charles De Villiers; Ginsberg, Samuel I
    The advent of CubeSats has provided a platform for relatively low-budget programmes to realise space missions. In South Africa, Stellenbosch University and the Cape Peninsula University of Technology have impressive space programmes and have been involved in numerous successful satellite launches. A number of CubeSat projects are currently in progress and commercial-grade Attitude Determination and Control Systems (ADCS), and communications modules, are being developed by the respective universities. The development of a CubeSat-compatible Electrical Power System remains absent, and would be beneficial to future satellite activity here in South Africa. In this thesis, some fundamental aspects of electronic design for space applications is looked at, including but not limited to radiation effects on MOSFET devices; this poses one of the greatest challenges to space-based power systems. To this extent, the different radiation-induced effects and their implications are looked at, and mitigation strategies are discussed. A review of current commercial modules is performed and their design and performance evaluated. A few shortcomings of current systems are noted and corresponding design changes are suggested; in some instances these changes add complexity, but they are shown to introduce appreciable system reliability. A single Li-Ion cell configuration is proposed that uses a 3.7 V nominal bus voltage. Individual battery charge regulation introduces minor inefficiencies, but allows isolation of cells from the pack in the case of cell failure or degradation. A further advantage is the possibility for multiple energy storage media on the same power bus, allowing for EPS-related technology demonstrations, with an assurance of minimum system capabilities. The design of each subsystem is discussed and its respective failure modes identified. A limited number of single points of failure are noted and the mitigation strategies taken are discussed. An initial hardware prototype is developed that is used to test and characterise system performance. Although a few minor modifications are needed, the overall system is shown to function as designed and the concepts used are proven.