What is an automobile circuit? What's the difference with ordinary circuits?

1. Schematic diagram of complete vehicle circuit:

In order to meet the needs of production and teaching, it is often necessary to find the starting point and ending point of a certain circuit as soon as possible in order to determine the route of fault analysis. When analyzing the cause of the fault, we should not be confined to a certain part in isolation, but should state the position of this part of the circuit in the whole vehicle circuit and its connection with related circuits. The advantages of vehicle circuit diagram are:

(1) has a complete concept of vehicle circuit, which is both a complete vehicle circuit diagram and an interrelated local circuit diagram. The key points and difficulties are prominent and the complexity is appropriate.

(2) The concept of high and low potential is established on this picture: its negative electrode "-"is grounded (commonly known as ground), and the potential is the lowest, which can be represented by the bottom line in the picture; The positive electrode "+"has the highest potential, which is indicated by the top line. The direction of current is basically from top to bottom, and the path is: power supply positive pole "+"→ switch → electrical appliance → grounding → power supply negative pole "-".

(3) Minimize the twists and turns of wires, make the layout reasonable, and make the drawing concise and clear. The graphic symbols take into account the shape and internal structure of components, which is convenient for readers to associate and analyze, and easy to read and draw.

(4) Local circuits (or subsystems) are connected in parallel with each other, and the relationship is clear. The connection points between generator and battery and between subsystems should be kept in the original position as far as possible, and the connections of fuses, switches and instruments should be basically the same as the original drawing.

2. Schematic diagram of local circuit:

In order to understand the internal structure of automobile electrical appliances, the relationship between components and the working principle of a local circuit, a local circuit that needs to be studied is often extracted from the circuit diagram of the whole vehicle, and other detailed information is referenced. If necessary, the key parts are enlarged, drawn and explained according to the field survey, inspection and test records. This circuit diagram uses less electrical appliances, has a small format, looks simple and clear, and is easy to read and draw. Its disadvantage is that it can only understand the part of the circuit.

Harness diagram

The wiring diagram of automobile circuit is often used for the connection, repair and wiring of assembly lines in automobile factories and repair shops. The wiring diagram mainly shows the connection parts of electrical appliances, the marks of terminals, the shapes and positions of wire ends and connectors, etc. It is an automobile circuit diagram that people can actually touch in the car. Generally speaking, this drawing does not describe the direction of wires inside the harness in detail, but only numbers or marks the wires and connectors exposed outside the harness in detail. It is a circuit expression that highlights the assembly mark, and it is very convenient for installation, wiring, detection and maintenance. If each line end of this diagram is accurately marked with serial number and color, combined with circuit schematic diagram and wiring diagram, it will play a greater role and get better results.

Automotive electricians should pay attention to:

First of all, we should have knowledge of electrician theory.

Secondly, you need to be careful and patient.

Finally, practice more and summarize, so that you can master it.