Principle of Electricity Generation

Electromagnetic Induction

An electrical conductor that can be moved freely is placed between the N and S (magnetic) poles of a magnet as shown in the diagram. Then, a galvanometer is connected to the conductor to complete a circuit.
When the conductor is moved between the magnetic poles as shown in the diagram, the indicator of the galvanometer swings.
Thus, when the conductor is moved between the magnetic poles, the conductor crosses and cuts off the magnetic flux, which generates a current. For this reason, if the conductor is moved parallel to the magnetic flux, no current will be generated. Read more Principle of Electricity Generation

Circuit Failures

Open Circuit

Click on the bulb mark or the underlined sentence.
An electrical device operates normally if there are no malfunctions in its circuit. The voltage at the connectors can be measured as shown in the diagram.
However, if an electrical device does not operate normally, its circuit may have failed in some manner.
In this case, the area of a malfunction can be identified by measuring the connectors. Read more Circuit Failures

Electrical Tester

Names of Parts
The  electrical tester can be used for measuring the current, voltage, and resistance of an electrical circuit, as well as to check the continuity of a circuit and testing diodes.

The following measurements can be performed by operating the function selector switch:
Alternating current voltage measurement
For measuring the voltage of household or factory power supply lines, alternating current voltage circuits, and the tap voltages of a power transformer.
Measurement method:
Set the function selector switch to the alternating current voltage measurement range and connect the test leads. The polarities of the probes are interchangeable.
Direct current voltage measurement Read more Electrical Tester

Relay and Fuse


If the electrical circuit for devices requiring a high amperage consists of a power source, a switch, and a light bulb that are directly connected, the switch and the wiring harness must be of a high capacity that can withstand the high amperage. However, through the use of a low-amperage current, a switch can turn a relay ON and OFF, which in turn, can apply the high amperage that flows to turn the light bulb ON and OFF.

The diagram on the left describes the mechanism of a relay. When the switch closes, the current flows between points 1 and 2, thus magnetizing the coil. The magnetic force of the coil attracts the moving contact between points 3 and 4. As a result, points 3 and 4 close and allow the current to flow to the light bulb. Thus, through the use of a relay, the switch and the wiring harness to the switch can be of a low capacity.

Read more Relay and Fuse

Parallel Connection & Series Connection


An electric circuit can be divided into a series connection or parallel connection, depending on how the electrical devices are connected.
1. Series connection
With this method, multiple electric devices are connected serially with a single electric wire.
Figure represents a series connection in the form of a water flow.
The uniqueness of this water flow is that an equal volume of water flows through each of these waterfalls, which is also equal to the volume of water that flows from the source.
(I0 = I1 = I2 = I3)
Moreover, the sum of the height of the three individual waterfalls equals the height of the entire waterfall.
(V0 = V1 + V2 + V3) Read more Parallel Connection & Series Connection

Basic of Electrical Circuit

Voltage and current

The speed of the waterwheel changes by changing the water volume in the tank. This means that the speed of the water flowing to the waterwheel changes with the change in the water pressure in the tank.
When this phenomenon of water is substituted with electricity, the water volume (water pressure) is the voltage, and the water flow is the electrical current.

Current and resistance
The force of the water flow changes with the height of the gate that is located between the tank and the waterwheel. As a result, the speed of the waterwheel changes.
This gate is equivalent to the resistance in an electrical circuit. Read more Basic of Electrical Circuit

Fundamentals of Automotive electricity

Electrical Circuit

Electrical devices are used in numerous areas of an automobile, and provide various functions.
As electricity passes through a resistor, it affects the resistor and can provide a number of functions.
Electrical devices utilize those functions according to purpose by converting electricity into work.
Functions of electricity
1. Heat-generation function
Heat is generated as electricity passes through a resistor, such as a cigarette lighter, fuse.
2. Light-emitting function
Light is emitted as electricity passes through a resistor, such as a light bulb. Read more Fundamentals of Automotive electricity