SPECIFICATIONS

Brand Name: QJSET

Choice: yes

Condition: New

High-concerned chemical: none

Max. Forward Current: 1A

Max. Forward Voltage: 1200V

Max. Reverse Current: 1A

Max. Reverse Voltage: 1200V

Model Number: IN4007 IN4001 IN4002 IN4004 IN4005

Origin: Mainland China

Package Type: Through Hole

Type: Rectifier Diode

Voltage: 220V

semi_Choice: yes

Product Introduction

A rectifier diode is a semiconductor device that converts alternating current (AC) into direct current (DC). It typically consists of a PN junction with two terminals: a positive terminal and a negative terminal. An important characteristic of a diode is its unidirectional conductivity. In a circuit, current can only flow into the diode through the positive terminal and out through the negative terminal.

Good electrical conductivity and stable performance

Rectifier diodes utilize the unidirectional conductivity characteristics of PN junctions to convert alternating current into pulsating direct current.

Rectifier diode

Stable performance  High power  Protection circuit

Positive and negative polesdifferentiation

The end marked with a white ring on the black casing of the rectifier diode is the negative terminal, and the other end is the positive terminal.

The end marked with a white ring is the negative pole,and the other end is the positive pole.

Product Introduction

A rectifier diode is a semiconductor device used to convert alternating current (AC) into direct current (DC). The most important characteristic of a diode is its unidirectional conductivity. In a circuit, current can only flow into the diode from the positive terminal and out from the negative terminal. Typically, it contains a PN junction with two terminals: a positive terminal and a negative terminal. Its structure is shown in Figure 2. The charge carriers in the P-region are holes, while those in the N-region are electrons. A certain barrier is formed between the P-region and N-region. When an external voltage is applied such that the P-region has a positive voltage relative to the N-region, the barrier decreases, and stored charge carriers are generated near both sides of the barrier, allowing a large current to flow with a low voltage drop (typically 0.7V), known as the forward conduction state. If an opposite voltage is applied, increasing the barrier, the diode can withstand high reverse voltages and only allows a small reverse current (referred to as reverse leakage current), known as the reverse blocking state. Rectifier diodes exhibit distinct unidirectional conductivity. Rectifier diodes can be manufactured using semiconductor materials such as germanium or silicon. Silicon rectifier diodes have high breakdown voltages, low reverse leakage currents, and excellent high-temperature performance. High-voltage, high-power rectifier diodes are typically made from high-purity single-crystal silicon (excessive doping can lead to reverse breakdown). These devices have a large junction area, enabling them to handle high currents (up to thousands of amperes), but they operate at low frequencies, generally below several tens of kilohertz. Rectifier diodes are primarily used in various low-frequency half-wave rectifier circuits; for full-wave rectification, they must be connected in a rectifier bridge configuration.

Characteristics

Rectifier diodes utilize the unidirectional conductivity characteristics of PN junctions to convert alternating current into pulsating direct current. Rectifier diodes have relatively high leakage current, and most are packaged using surface-contact type materials. Additionally, in addition to the parameters mentioned earlier, rectifier diodes also have a maximum rectification current, which refers to the maximum current value that the rectifier diode can withstand during prolonged operation. This is a primary parameter of rectifier diodes and serves as the main basis for selecting them.

Precautions

When selecting rectifier diodes, the main parameters to consider are high current, maximum reverse working current,cutoff frequency, and reverse recovery time.

Causes of damage

① Inadequate lightning protection and overvoltage protection measures.

② Poor operating conditions.

③ Poor operation and management.

④ Poor installation or manufacturing quality of equipment.

⑤ Incorrect specifications and models of rectifier tubes.

⑥ Insufficient safety margin of rectifier tubes.

Inspection method

First, remove all the rectifier diodes from the rectifier. Using the 100×R or 1000×R ohm setting on a multimeter, measure the two leads of each rectifier diode (swap the leads and measure each one separately). If the resistance values measured in the two tests differ significantly, for example, the higher resistance value is as high as several hundred kΩ to infinity, while the lower resistance value is only several hundred ohms or even smaller, this indicates that the diode is in good condition (except for diodes that have experienced soft breakdown). If the resistance values measured in the two tests are almost equal and the resistance value is very small, this indicates that the diode has been damaged by breakdown and cannot be used. If both measured resistance values are infinite, it indicates that the diode has internally broken and cannot be used.