Wiring diagrams are "maps" that provide a guide for assembling an electronic circuit, performing maintenance work on it and understanding its operation. Without this representation, in the eyes of the user or a technician, the circuit is simply a mass of components and electrical wires. The diagram allows you to understand the operation of the circuit and to become familiar with how to intervene to obtain a certain effect; use the tips in this article to learn how to read one.
Steps
Step 1. Read the schematic in the same way as you would read a text
Except for rare exceptions, this diagram reads from left to right and top to bottom; the signal used or generated by the circuit flows in this direction. The user can follow the same path of the electrical signal to understand how it behaves and how it is modified.
Step 2. Learn electronic jargon
You can see several symbols that represent real terms from the world of cables and electrical devices. To be able to read one of these patterns, it is necessary to have a basic knowledge of these symbols; you can find different lists and legends by searching online.
- Understand grounding. It is represented by a downward facing triangle or series of parallel segments that gradually become shorter, defining an inverted triangular shape. Grounding is a common reference point used in diagrams to show the general unity of various circuit functions and does not refer to actual ground grounding.
- Know that a line represents an electrical connection. Cables are used to connect devices to each other, all points along a wire are identical and connected. The lines representing them may intersect in the diagram, but this does not mean that the actual cables are connected in the real circuit. If they are not joined, it is indicated with a ring symbol or a semicircle at the intersection; if they are connected, the lines cross and there should be a dot.
- The resistor is indicated with a zigzag line. This element performs the function of opposing a certain resistance to the flow of electric current; it is used to modulate and resize the signal.
- Learn Ohm's Law. The voltage across a resistor is equal to the intensity of current flowing through it multiplied by the value of the resistance (V = IR). This explains why the resistor is typically used to reduce voltage; if this is applied to two consecutive resistors of the same value, the number of volts measured at the center of the two resistors is halved compared to the original one.
- Know that capacitors are represented with two parallel lines. They are used to modulate electrical signals that change rapidly, as opposed to the static or slowly changing ones that are modulated by resistors. Capacitors are traditionally used in modern circuits to remove noise from the signal and discharge it to ground; noise is an innate characteristic of the rapidly changing signal.
- Understand non-standard signals. These are graphical representations and geometric shapes (usually rectangles) with a reference number inside or next to them. An indicator could be "Uxx". Wherever a cable connects to a device, there is a number that indicates the connection point and which corresponds to the pin of the device itself.
Step 3. Find the correlation between all real elements
Refer to the circuit material list to find capacitor and resistor ratings, as well as the serial number and manufacturer name of the various active devices.
Step 4. Determine the circuit function performed by the active devices
To do this, obtain and read the manufacturer's information sheet for each individual device.
Step 5. Evaluate the work done by the circuit
Based on the information in the wiring diagram, you define which parts perform certain functions; in this way, you can estimate the performance of the whole circuit.
Advice
- The signals can be present simultaneously in many parts of the circuit; do not assume that they start in one place and are only directed to one place. No matter how many points are connected to the signal through the cable, the signal exists in all of them simultaneously.
- The capacitors are polarized; they have a plus sign (+) on one end, which means they must be installed in a certain way, which does not affect the performance of the circuit.
