How to use rectifier diode? The rectifier diode is suitable for various electrical appliances that use DC as the working power supply. The AC in the power supply circuit is used as the DC power supply of the load circuit after rectification, filtering and voltage stabilization. Such as lighting, charger power supply, various small household appliances power supply, etc. The following describes in detail the precautions for the use of rectifier diodes.
Purpose and function of rectifier diode: it is used for AC-DC rectifier conversion to meet the requirements of DC power supply in circuit design function.
Precautions for use of rectifier diode
(1) When the lead is formed and bent, the lead must be fixed and clamped with a clamp at the bending position of the lead, and the plastic sealed pipe body cannot be fixed and clamped, so as to prevent the mechanical stress from being directly applied to the joint of the pipe body and the lead;
(2) Lead bending must be carried out at a distance of 3mm from the pipe body;
(3) The bending angle of the lead shall not be greater than 90 °, and the lead shall not be bent repeatedly;
(4) The cutting and forming tools shall not damage the coating on the lead surface.
(5) The allowable welding heat resistance condition of the device is below 260 ℃ and the duration is no more than 10 seconds. Welding shall be carried out at least 2mm away from the body. The tin dipping temperature shall not exceed 260 ℃, and the time shall not exceed 10 seconds.
(6) When flux is necessary for PCB welding, please use neutral flux and conduct necessary cleaning to remove excess flux.
(7) During wave soldering, please set up sufficient preheating zone. The preheating time is recommended to be in the range of 30 ~ 60s to alleviate thermal shock.
(8) JEDEC standard is recommended for reflow welding conditions (preheating temperature is 125 ± 25 ℃, preheating time is 120 ± 30s; duration above 183 ℃ is 105 ± 45s; peak temperature is 235 + 5 / - 0 ℃, duration is 10 ~ 20s. Zui large temperature rise rate is 3 ℃ / s, and cooling rate is 6 ℃ / s).
(9) When dipping tin with electric soldering iron, the temperature of electric soldering iron head shall not exceed 300 ℃, and the welding time shall be less than 10 seconds. Metal tweezers are used between the electric soldering iron and the device to reduce the direct heat transfer to the inside of the device;
(10) Reflow soldering should be used for surface mount devices. Zui common soldering methods include convective reflow, vapor reflow and far infrared reflow. The reflow soldering process is divided into three stages: preheating, reflow soldering and cooling. JEDEC standard is recommended for reflow welding conditions (preheating temperature is 125 ± 25 ℃, preheating time is 120 ± 30s; duration above 183 ℃ is 105 ± 45s; peak temperature is 235 + 5 / - 0 ℃, duration is 10 ~ 20s. Zui large temperature rise rate is 3 ℃ / s, and cooling rate is 6 ℃ / s).