/library/oar/handle/123456789/92579 2025-12-27T07:24:20Z /library/oar/handle/123456789/102092 Title: Analysis and design of transistor resistor logic (TRL) circuit for digital computers Abstract: The object of this project is to analyse and to develop design procedures for a Transistor Resistor Logic (TRL) circuit to be used later for the construction of a 15 NOR circuits Teaching Kit (Dan-Gal) to be used for demonstrations of some Boolean Algebra principles. The basic circuit consists of ONE transistor and a number of resistors. This circuit may then perform the NOT, OR and AND functions. The first requirement for operation of this circuit is that the transistor must be saturated if ONE or more inputs are low. The second requirement is that the transistor must be cut off if ALL of the inputs are high. A ‘worst case’ analysis is performed for each of these requirements. Calculated and measured TURN – ON, TURN – OFF and STORAGE times values were performed on 0C83 transistor in order to understand better how and to what extent the values of collector current and base current etc. in the d.c. equations would affect the switching times of the transistor. A procedure has been followed to optimise for minimum required transistor base current. A solution was tried to obtain an ‘optimized’ value to build a NOR circuit of fan-in of 4 and fan-out of 1. Some methods have been also discussed to show how speed-up circuits can be used to give better switching times. Comparison of performance has been made between a NOR circuit used by Lan-Dec Computer Teaching Kit and the one designed by the theory outlined in this paper. The validity of the theory was tested on the Dan-Gal,- Educational Kit built for this purpose by programming some logic functions. Description: DIP.ENG. 1970-01-01T00:00:00Z /library/oar/handle/123456789/102091 Title: Locator of hidden P.V.C. installation conduit Abstract: The use of plastic conduits for concealed installation is legally inadmissable in certain areas, in Malta, for fear that any nails penetrating the walls might establish metallic contact with the live wires of the installation with the possibility of causing accidents through electrocution. It is in this context that this investigation was carried in order to assess the adaptability of the metal locator in tracing concealed wiring in walls or underground. The results of this investigation were not really encouraging but had time permitted we would have followed the matter up by attempting to increase the sensitivity by: 1. Matching the load (i.e. ammeter) resistance to the anode resistance of the amplifier load. 2. Increasing the input voltage to pin2 of the operational amplifier 1C2 through VR2. This attempt would have fully exploited the advantages of plastic conduit vis a vis steel conduit since it can be manipulated with comparative ease. It is therefore less demanding upon the skill of the worker and the time of completion is much shorter. Hence the task would be less expensive and executed in a shorter time. In preparing this project I have made use of material supplied by the Electrical Department of the University and with the help of the technical staff who permitted me to make use of the facilities present in the laboratories and workshop. Finally, I wish to express my appreciation to Profs., Daniel Minto ff, B.Sc., Eng. (LORD), C.Eng. M.I.E.E., Lecturer in charge, for his help and supervision. Description: DIP.ENG. 1978-01-01T00:00:00Z /library/oar/handle/123456789/102089 Title: A survey of electrical engineering in a hospital Abstract: This thesis was made as part of the study which was carried out during the last year of the Higher Technicians Diploma in Electrical Engineering, C and G course 800. The aim of this project was to carry out a survey of the various electrical and electronic engineering applications relevant to hospitals in Malta. It was intended that the survey would cover the following various applications of electrical and electronic engineering with particular reference to hospital services. The topics covered were: 1. Electrical power distribution and emergency supplies 2. X-Ray equipment 3. The E.C.G. and other medical electronic equipment We would like to thank our project supervisor Mr. J.A. Agius B.Sc. (Tech), C.Eng, M.I.E.E. for his continuous interest in helping us with the difficulties we met while preparing this thesis. We would like to thank also Mr. A. Axisa B.Sc (Eng), C.Eng, M.I.E.E., M.I. Hosp E., M.I.E.R.E. and Mr. L. Agius T. Eng (C.E.I.), A.M.I.E. of the St. Luke’s Hospital from whom we received great technical assistance; Mr. J. Attard B.A. for revising the project and Miss Mariella Mifsud for typing our work. Description: DIP.ENG. 1979-01-01T00:00:00Z /library/oar/handle/123456789/102079 Title: Ship electrical power supply Abstract: Power supplies for the sea going crafts take a lot of forms, that is direct current and alternating supplies. A.C. currents may be found in a variety of frequencies. Small boats, do need, if any, little power which can be supplied from batteries or sometimes from small portable generators. These crafts usually need less than a few hundreds of watts. The loads are lighting, navigation lighting, and power for self starting engines. As the size of the craft is increased the load demand increases rapidly since these usually fall under the category of leisure boats, one would expect to find certain commodities apart from the ship’s necessities which are needed such as pumps, whinch motors, etc. The types of supplies dealt with in this project report are those found on ships demanding from 100 to 2000 K.W. The most common modern systems encountered on ships are 380V 3ph 50Hz and the 440V 3ph 60 Hz. D.C. supplies are still much common on existing ships of the older type so this project will also contain a brief review about D.C. generation as applied for ships. The sources of power on ships may also be, or part of it be, the battery. As stated this project will consider: Batteries ; generators ; dc generators ; ac generators Description: DIP.ENG. 1980-01-01T00:00:00Z