CHAPTER. Fundamentals of Electricity. 2. Instructor Name: (Your Name ). Learning Objectives. Relate electrical terms including voltage, current, and resistance to their hydraulic or pneumatic counterpart Explain the relationship among voltage, current and resistance in an electrical circuit
Fundamentals of Electricity
Instructor Name:(Your Name)
Figure 2-6 Charges suspended from strings.
Atoms are like a solar system; protons are the sun with electrons orbiting like planets.
Figure 2-7 Copper Atom.
Figure 2-8 Opposite charges on the paper and comb cause an attraction.
Figure 2-9 Electron flow is like the movement of cars to the right, while conventional flow is like the movement of spaces to the left.
Figure 2-10 Electron flow is like marbles in a tube: a marble that enters the tube on the left is not the same marble that exits the tube on the right.
Figure 2-15 Electrical resistance cause heat and light when electric current flows through the light bulb filament.
Figure 2-14 Light bulb filament has a much smaller diameter than the wires connected to the light bulb causing an opposition to the flow of electric current.
Figure 2-16 Ohm’s law memorization aid.
Figure 2-17 Electric symbols used to construct electrical schematic.
Figure 2-22 Digital multimeter.
Figure 2-24 Measuring Voltage.
Figure 2-26 Measuring current with an ammeter.
Modern DMM are fantastic tools but have fooled almost every technician at one time or another. One reason for this is just a miniscule amount of voltage present in a circuit when resistance is being measured can result in dramatic resistance measurement errors. The miniscule voltage can be generated by engine coolant or water in contact with dissimilar metals, as will be explained in more detail in later chapters. If resistance measurements do not make sense, measure the voltage that is present between the two points of which you want to know the resistance. If the DMM displays any voltage, your resistance reading will not be accurate.
Figure 2-28 Clamp-on current probes.
Figure 2-33 Using a differential pressure gauge.
Figure 2-40 Measuring voltage drop and current flow.
Figure 2-41 Increasing resistance.
Figure 2-44 Difference in the voltage dropped across unequal series resistors.
Figure 2-50 Solved series-parallel circuit.
Figure 2-49 Series-parallel simplification progression.
Figure 2-51 Common metric prefixes used in electrical system troubleshooting.
Figure 2-52 Three resistors in parallel. Note the measured resistance value is less than any of the parallel-connected resistors.