When we talk about the positive and negative terminals of a circuit, we usually default to the positive and negative terminals of the power supply,2 oz copper thickness in mm and it's the positive and negative terminals of DC power. So how to identify the positive and negative poles on the circuit board?

1, through the silkscreen to determine

Electronic engineers in the design of the PCB, usually butt the interface part of the pin silkscreen marking. For the power supply positive and negative poles, engineers generally use V + and GND to label. Therefore, we can judge the positive and negative poles by looking at the contents of the silkscreen on the circuit board. Typically, V+ indicates the positive terminal, while GND is an abbreviation for the ground end of the wire, which stands for ground or 0. This ground is not really a ground, but a ground assumed based on the application, and in the case of a power supply, it is the negative terminal of the power supply.

So how to determine the positive and negative poles on a board that is not labeled input (output) positive and negative poles?

2, according to the polarity components to determine

Polarity components can not be reversed when used, because they have polarity. Common polar components are electrolytic capacitors, diodes and so on. Therefore, we can determine the positive and negative poles of the circuit through these components with polarity. Electrolytic capacitors, for example, the positive electrolytic capacitor must be connected to the positive terminal of the power supply V +, while the negative terminal must be connected to the GND. if you correctly identify the capacitor's pins, you will be able to determine the circuit's positive and negative poles.

3, according to the large area of the copper to determine the

In order to improve the anti-interference ability and reduce the impedance of the ground,plated through hole vs via electronic engineers in the design of the PCB will be a large area of copper cladding way to achieve electrical connections. If the circuit board for copper cladding, basically GND as a network of copper cladding. Therefore, we can judge the large copper-coated area for the ground in turn.

4, other ways

You can also determine the positive and negative poles according to the pins of the chip. Chips usually need power supply and have power supply pins. If we understand the order of the chip's pins, we can distinguish the positive and negative poles of the power supply. However, this method has the drawback that it is only applicable when there is only one power supply network. If there are multiple power supply networks on the board, it is necessary to further use the above method to determine.

In summary, we can identify the positive and negative poles on the circuit board through silkscreen, polarized components, large copper cladding, and chip pins. By choosing the appropriate method according to the specific situation, the positive and negative poles of the circuit can be accurately determined.