Basic knowledge training of SMD electronic component

In all electronic circuits, our commonly used SMD electronic components include: SMD resistor, SMD capacitor, SMD

Diodes, SMD  transistor, etc.

Explains four commonly used mainstream SMD component. Can be used as a reference in daily applications.

One, SMD resistor

As the most commonly used equipment in circuits, SMD resistor are often called

Resistance. Resist almost

As the name suggests, non-carbonized equipment in electronic circuits

The role of resistance is to hinder the role of electrons. Main circuit work

The rated power of the resistor should be replaced with 1.5~2 times the actual power

To ensure that the resistance is durable. Use a multimeter before inserting the resistor into the circuit

Ohm file to verify its resistance. When installing, make resistance type

Symbols such as value are easy to see, and the Cavaliers verified this.

Second, the SMD capacitor

SMD capacitor are also one of the most commonly used basic electronic component

.

Used in tuning, filtering, conversion and side-by-side circuits

Road, energy conversion and delay, etc. Frequency and withstand voltage should be considered when replacing SMD capacitor. electrolysis

Also pay attention to the polarity of the capacitor so that the + pole is connected to the DC high voltage

The operating temperature should also be considered. Continuous working ring depends on the design of SMD capacitor

Ambient temperature range. The scope depends on its corresponding category

Temperature limit values, such as upper limit category temperature, lower limit category

Temperature, rated temperature (rated voltage can be applied continuously

Maximum ambient temperature) and so on.

Three, patch diode

The positive characteristic of the SMD transistor: the first quadrant part of the characteristic curve, the curve

It has an exponential curve shape and is non-linear. Forward when the forward voltage is very low

Currently almost zero, this interval is called "dead zone"

, Corresponding to electricity

The voltage range is called the dead zone voltage or threshold voltage. Dead zone voltage of germanium tube

The voltage is about 0.1V, and the dead zone voltage of the silicon tube is about 0.5V.

Reverse characteristics: the reverse current is very small, but when the reverse voltage is too high

When the PN junction breaks down, the reverse current increases sharply.

Four, patch transistor

SMD transistors are classified according to structure, point contact type and surface contact type. According to working frequency

The speed is divided into high-frequency triode, injection triode, switch tube. According to power

Divided into high power, medium power and low power transistors. From a packaging perspective, there are

Various forms such as metal packaging and plastic packaging. Due to the diversity of transistors,

There are some specific models in this category, so they can be distinguished in advance during use.

Negligence will damage the transistor.