Light is a symbol of human civilization, and LED is a new light source in the 21st century. LED is in line with modern concepts: green, healthy, environmentally friendly, energy-saving, and long life. Although LEDs have greater adaptability and longevity compared to incandescent lamps, the following requirements should be noted during application and use to ensure stable, long-term operation of the LEDs.
First, voltage and current1. It is not recommended to use LEDs in parallel, because even the same model, the operating voltage of the same batch of LEDs will be different, unless the current sharing circuit is done.
2. When installing ultra-bright white LEDs, anti-static facilities should be provided, because the super-bright white LEDs damaged by static electricity will reduce the service life even if they are not visible to the naked eye.
3. If the operating voltage of the LED changes by 0.1V, the operating current may vary by about 20mA. Usually, a series current limiting resistor is used, and a simple constant voltage circuit can also be used, so as to achieve automatic voltage limiting and current limiting to prevent damage to the LED.
4. The peak current of ordinary LED is 50~100mA, and the reverse voltage is about 6V. When applying LED, pay attention to the peak voltage and current when designing the circuit. (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 conditions1. Soldering iron welding:
When soldering with a soldering iron for manual soldering, it is required to use a soldering iron of less than 25W (up to 30W), and the temperature of the soldering iron must be kept below 300 °C, generally recommended at 260 °C. Do not solder for more than 3 seconds.
2. Dip soldering:
Dip soldering requires a tip temperature of 260 ° C, a dip soldering time of no more than 5 seconds, and a dip soldering position of at least 2 mm from the colloid.
Remarks: After soldering, wait carefully when the temperature of the LED product drops to room temperature. Do not use hard objects and sharp objects to scrape, rub, bump, squeeze, or press the LED.
1. Pay attention to the arrangement of the outer lines to prevent the wrong polarity.
2. Do not get too close to the heating element.
3. Do not install the LED with the pin bent.
4. When installing the LED, it is recommended to use the guide sleeve to position.
5. Do not subject the LED to vibration or external force until the soldering temperature returns to normal.
Fourth, component cleaningThe following procedure should be used for cleaning after soldering.
1. The cleaning solvent can be selected from Freon TF or alcohol, or other similar solvents.
2. The cleaning temperature is controlled at 30 ° C for 30 seconds or 30 ° C for 3 minutes, but the temperature is not too high.
3. When using ultrasonic cleaning, the maximum power should not exceed 300W.
Remarks: Pay attention to the cleaning of colloids with chemicals, because trichloroethylene, acetone, etc. will damage the surface of the colloid. It can be wiped and dipped with ethanol, but it should not be more than 3 minutes.
Five, temperature characteristicsAccording to the temperature characteristics of the LED, the temperature rises by 5 ° C, and the luminous flux decreases by 3%. Pay attention to the LED operating temperature and storage temperature regardless of the winter or summer.
1. LED LAMPS The minimum operating temperature is -25 ° C up to 85 ° C, the minimum storage temperature is -40 ° C up to 100 ° C.
2. The minimum operating temperature of the LED display screen is -20 °C up to 70 °C, and the lowest storage temperature is -20 °C up to 85 °C.
3. The outdoor LED (OUT-DOOR LED LAMPS) has a minimum operating temperature of -20 ° C up to 60 ° C and a minimum storage temperature of -20 ° C up to 70 ° C.
Six, other matters needing attentionExposed SMD LEDs at high temperatures, do not squeeze the epoxy part of it, or scratch it with other sharp objects, because Epoxy is very fragile and extremely fragile.
What is the practical use of LED explosion-proof lamps?Many people don't know much about how this product is when they buy LED explosion-proof lights. I have collected some information for your reference and hope to be useful to everyone.
First of all, a simple introduction to the LED explosion-proof lamp, the LED explosion-proof lamp is a kind of explosion-proof lamp, the principle is the same as the explosion-proof lamp, but the light source is the LED light source, which means to prevent the ignition of the surrounding explosive mixture such as explosive gas environment, explosive dust Luminaires for various specific measures taken in the environment, gas, etc.
One of the most important explosion-proof principles of LED explosion-proof luminaires is to limit the temperature of the surface of the casing in contact with explosive gases, explosive dust, the surface of components or the surface of electronic components, and to limit the temperature of the electrical contact surface below its minimum ignition temperature or ignition temperature. .
Since LED is a solid-state cold light source, it has the advantages of high electro-optical conversion efficiency, low heat generation, low power consumption, safe voltage and low voltage, and long service life. Therefore, high-power white LED is an explosion-proof lamp, especially portable explosion-proof. A very ideal electric light source for lamps.
"Figure 1-1 is: integrated LED explosion-proof lamp"
LED explosion-proof lamp, which belongs to a kind of electrical equipment used in special industries, mainly solves lighting problems. It includes a lamp housing, a lamp cover disposed at the front end of the lamp housing, an illuminator and a battery disposed inside the lamp housing, and a switch disposed on the surface of the lamp housing. The utility model is characterized in that: the illuminant is a high-power LED module, and a wide voltage input driving circuit is arranged between the illuminant and the battery; the wide voltage input driving circuit comprises a constant current chip, the constant current chip and the battery form a power module, and the LED The module is connected to the constant current chip, and the power module is glued together with the LED module; ultrasonic welding is performed between the lamp cover and the lamp housing. It utilizes the characteristics of low heat generation of LED to achieve intrinsically safe explosion-proof, and the LED light source has a long service life; the battery maintains constant brightness at the end of full charge and discharge; the heat dissipation device is arranged on the lamp housing to achieve effective heat dissipation of the LED module It guarantees the stability of use and is suitable for lighting in various industries such as coal mine, petroleum, railway and flood control. Applicable to hazardous areas in Zone 1, Zone 2, IIA, IIB, IIC explosive gas environment.
"Figure 1-1 is: polycrystalline LED explosion-proof lamp"
LED explosion-proof platform lights are mainly used for fixed lighting in petrochemical plants, oil platforms, gas stations, oil pump rooms, transfer stations and other inflammable and explosive places. Its explosion-proof mark: Exd II BT6 Gb, protection grade: IP66.
LED explosion-proof lamp performance characteristics:
â– The lamp has unique light distribution, the illumination range is uniform, and the illumination angle is up to 220 degrees. The light is fully utilized; the light is soft and there is no glare.
It will not cause eye strain of the operator and improve work efficiency.â– The chip is generally used in Taiwan's Puri, Jingyuan, American Corey and other brands, the power consumption is only 40% of the metal halide lamp.
â– All key components of the power supply are selected by the world's top brands, which are efficient and stable.
â– Adopting unique heat dissipation structure, using heat transfer and heat conduction to accelerate heat conduction, effectively ensuring efficient heat dissipation of LEDs, so that LED life can reach 100,000 hours.
â– The explosion-proof type has the highest explosion-proof grade and can be used in flammable and explosive places in various industries.
â– Can be connected in parallel, eliminating the need for junction boxes and installation costs.
â– The shell is made of high-tech surface spraying technology, which is wear-resistant, corrosion-resistant, waterproof and dustproof, and is suitable for various harsh environments.
Planar Die Construction Sealed Glass Case Ideally Suited for Automated Insertion - 75V Nominal Zener Voltages
Case: MiniMELF, Glass Terminals: Solderable per MIL-STD-202, Method 208 Polarity: Cathode Band Approx. Weight: 0.05 grams
= 25°C unless otherwise specified Symbol Pd VF RqJA Tj, TSTG Value to +175 Unit mW V K/W °C
Characteristic Forward Voltage = 200mA Thermal Resistance, Junction to Ambient Air (Note 2) Operating and Storage Temperature Range Notes:
1. Tested with Pulses, 20ms. 2. Valid provided that Electrodes are kept at Ambient Temperature.
1. Tested with pulses = 20 ms. 2. Valid provided that electrodes are kept at ambient temperature.
VZ, ZENER VOLTAGE (V) Fig. 1, Zener Current vs Zener Voltage
25 20 VZ, ZENER VOLTAGE (V) Fig. 8, Zener Current vs Zener Voltage
TA, AMBIENT TEMPERATURE (°C) Fig. 3, Power Dissipation vs Ambient Temperature
15 20 VZ, ZENER VOLTAGE (V) Fig. 4, Differential Zener Impedance
VZ, ZENER VOLTAGE (V) Fig. 5, Junction Capacitance vs Zener Voltage
MELF
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