Marine Electrical - Electricity Laws and Circuits

Course description

Electric current can be classified as direct or alternating based on its direction of flow. We use direct current (DC) and alternating current (AC) in different locations based on the requirements of a system. CD is obtained using batteries, DC generators and solar cells etc. The current is unidirectional (it will not change its direction for every half-cycle as alternating current does). In this course, you learn about the effects of connecting DC sources in series and parallel. The flow of charges results in an electric current. In a wire, electrons carry the charges. However, in an electrolyte, both electrons and ions carry the charges. The SI unit of electric current is an ampere. In an electric current, the particles that carry electric charge are charge carriers. AC is the current running through the wires and appliances on most ships. An AC waveform can be sinusoidal, square, or sawtooth-shaped. Alternating current electricity is the type of electricity commonly used worldwide, including onboard large vessels. The voltage of an AC power source changes from instant to instant in time.

The course begins by analysing Ohm's Law and the voltage, current, and resistance in the relationship that gives rise to this law. Investigate the series connections of power source, resistances, inductances, and capacitors along with the effects of such connections. You will understand power, its SI unit, and how it relates to the rate of work and energy. We illustrate potential dividers and their use in electrical circuits. We also walk you through the characteristics of electric current flow in parallel circuits, alongside voltage and resistance quantities. The effects and limitations of Ohm's Law and the series-parallel connections of electric circuits are outlined. You will study Kirchhoff's Current Law (KCL), relating complex circuits with different power sources and branches that you cannot solve with Ohm's Law. We examine Kirchhoff's Voltage Law and its application to circuits with voltage supply. The direction, source, and the comparison of DC and AC is analysed. You will also learn about a magnetic field's basic concepts, properties, and effects on a conductor in the section about electromagnetism.

This course provides an understanding of electromotive force (EMF) generation, Faraday's Laws, and the methods of producing induced EMF. By taking it, you will study the practical AC generator in addition to the quantity of the instantaneous value of induced EMF. We also examine the frequency of EMF induced in a generator and the formula used to determine the magnitude of induced EMF. Study the concepts used in waveform and the sinusoidal variation of EMF, and the step-by-step process of calculating the average values of sinusoidal current. You will also study an alternating current's root mean square (RMS) value. Master the concepts of phasors representation, addition, subtraction, and J operators. Lastly, you will learn about AC circuits with resistors along with the power in a resistive circuit.