Components generally have polarity, and how to judge the polarity direction of components? This is a difficult problem for many beginners, and may be more daunting than looking at a circuit diagram. Since there are too many types of components, here are only a few typical components as representatives to introduce how to identify the direction and polarity of components.
IC chip pin label
How to Identify the Direction Polarity of Components
As shown in the picture above, on one side of the many pins, there is a small hole on one of the pins. The hole represents the pin here as the first pin. If the pins are sorted, it's "pin 1". When a general PCB board is packaged, a gap will be reserved, and both the gap and the round hole are square. When soldering or repairing IC chips, pay attention to identifying round holes or notches.
Positive and negative identification features of polar in-line capacitors
The package shape of the capacitor is usually black and gray, with more black and only one gray. There will be a rectangular symbol "-" in the gray bar, and the pin below the gray bar is the negative electrode. The "—" symbol represents the negative pole. In addition to the color symbol distinction, the length of the capacitor's pins is divided into long and short, the long pin is positive, and the short pin is negative. The length of the pin can also be used to identify the positive and negative poles of the in-line LED.
Polarity SMD Capacitor Polarity Identification Characteristics
Ring-colored long block components are often seen on circuit boards, which are polar chip capacitors. When identifying, pay attention to the corners of the patch, there is a darker area, orange or gray. The darker section is the positive, and the other is negative.
In-Line Diode Electrode Identification Characteristics
As mentioned above in the identification of polarized capacitors, the length of the pins can also be used to judge the direct insertion of LEDs. In-line diode type device identification can also be distinguished by color. As a one-way conductive element, the diode has a very large resistance on one side and a very small resistance on the other side. When the diode is reversed, the entire circuit board circuit will be broken. Such diodes also have two colors. Unlike capacitors, the direction of the gray area represents the negative electrode, and the black side with more colors is the positive electrode, so do not mix capacitors and diodes.
SMD diode polarity identification characteristics
In addition to in-line diodes, there are also SMD diodes. The identification method of positive and negative electrodes of SMD diodes is the same as that of in-line diodes. One side of the gray horizontal bar is the negative electrode, and the other end is the positive electrode.