First, the voltage and current
1. Do not recommend the use of LED in parallel, because even the same model, the same batch of LED operating voltage has a certain difference, unless the current circuit.
2. In the installation of ultra-bright white LED, there must be anti-static facilities, because the electrostatic damage to the ultra-bright white LED even if the naked eye can not see, will reduce the service life.
3. If the LED operating voltage changes 0.1V, then the working current may change about 20mA. Under normal circumstances the use of series current limiting resistor, you can also use a simple constant voltage circuit, the purpose is to do automatic pressure limiting current limiting, to prevent damage to the LED.
4. The peak current of ordinary LED is 50 ~ 100mA, the reverse voltage is about 6V. When applying LED, pay attention to the design of the circuit when the peak voltage and current do not exceed this limit. (Except for special and high power) When the peak voltage of the circuit is too high, it is very likely to damage the LED.
Second, the welding conditions
1. Soldering iron:
Weld soldering iron soldering requires less than 25W (up to 30W) of soldering iron, and the soldering iron must be kept at a temperature not higher than 300 ° C. It is generally recommended at 260 ° C. The welding time should not exceed 3 seconds.
2. dip welding:
Dip welding requirements of the tip temperature of 260 ℃, dip welding time of not more than 5 seconds, dip welding position at least 2 mm from the colloid.
Note: After welding, wait for the temperature of the LED product to drop to room temperature and then be careful. Do not use hard objects and sharp objects to scrap, Sassafras, touch, squeeze, pressure LED.
Third, the installation method
1. Note the arrangement of the outside line, to prevent the wrong polarity.
2. Do not be too close to the heating element. The following are the same as the "
3. Do not install LEDs when the pins are bent and deformed. The following are the same as the "
4. When installing LED, it is recommended to use guide sleeve positioning. The following are the same as the "
5. Do not let the LED be subjected to vibration or external force until the welding temperature returns to normal.
Fourth, the component cleaning
After welding, the following procedure should be carried out for cleaning.
1. Wash the solvent can be used freon TF or alcohol, or other similar solvents.
2. Cleaning temperature control at 30 seconds up to 50 ℃ or 3 minutes up to 30 ℃, the temperature is too high.
3. When using ultrasonic cleaning, the maximum power should not exceed 300W.
Note: cleaning chemicals with chemicals should pay attention to, because such as trichlorethylene, acetone, etc. will damage the colloid surface. You can use ethanol to wipe, dipping, but not more than 3 minutes.
Fifth, the temperature characteristics
According to the temperature characteristics of LED, the temperature rises 5 ℃, luminous flux decreased by 3%, regardless of the winter or summer use should pay attention to LED operating temperature and storage temperature.
1.LED LAMPS minimum operating temperature of -25 ℃ up to 85 ℃, the minimum storage temperature of -40 ℃ up to 100 ℃. The following are the same as the "
2.LED display screen minimum operating temperature of -20 ℃ up to 70 ℃, the minimum storage temperature of -20 ℃ up to 85 ℃. The following are the same as the "
3. Outdoor LED lights (OUT-DOOR LED LAMPS) the minimum operating temperature of -20 ℃ up to 60 ℃, the minimum storage temperature of -20 ℃ up to 70 ℃.
Six other matters needing attention
Exposed SMD LEDs in high temperature conditions, do not squeeze its epoxy parts, or scratch with other pointed objects, because Epoxy is very fragile and easily damaged.