PUR cable is a type of cable that is specifically designed to withstand exposure to oil and other petroleum-based substances. The sheath of the cable is made from a material called polyurethane (PUR), which is known for its resistance to oil, chemicals, and abrasion. Oil Resistant PUR Sheathed Cable,Highly Resistant Against Wear Cable,Shielded Polyurethane Cable,Oil Resistant Cable Ruitian Cable CO.,LTD. , https://www.hbruitiancable.com
The oil resistance of this type of cable makes it ideal for use in industrial environments where there is a high risk of exposure to oil or other similar substances. It can be used in applications such as oil refineries, chemical plants, and automotive manufacturing facilities.
The PUR sheath also provides excellent mechanical protection, making the cable highly durable and resistant to damage from impacts or abrasion. This makes it suitable for use in harsh environments where the cable may be subjected to heavy use or rough handling.
In addition to its oil resistance, PUR sheathed cable often has other desirable properties such as flame resistance, UV resistance, and flexibility. These properties make it a versatile choice for a wide range of applications where durability and reliability are important.
Overall, PUR cable is a reliable and durable option for applications that require protection against oil and other petroleum-based substances. Its ability to withstand harsh environments and resist damage makes it a popular choice in various industries.
Important parameters of LED chip and analysis of two structures
The LED chip is the core component (LED lamp) of the semiconductor light-emitting device LED, and the principle of LED illumination mainly lies in the PN junction of the LED chip. In general, a semiconductor chip consists of two parts, a part of which is a P-type semiconductor, in which a hole dominates, and the other end is an N-type semiconductor, which is mainly electrons here. But when the two semiconductors are connected, they form a PN junction (LED TV).
When a current is applied to the chip through the wire, the electron is pushed to the P region. In the P region, the electron recombines with the hole, and then the energy is emitted in the form of a photon. The wavelength of the light is also the color of the light. Determined by the material forming the PN junction (LED display).
The LED chip is mainly composed of several elements such as arsenic (AS), aluminum (AL), gallium (Ga), indium (IN), phosphorus (P), nitrogen (N), and bismuth (Si). It is a single crystal.
LED chip classification
Uses: According to the use, it is divided into high-power LED chip and low-power LED chip;
Color: Mainly divided into three types: red, green, blue (raw materials for white light);
Shape: Generally divided into square pieces and round pieces;
Size: Small power chips are generally divided into 8mil, 9mil, 12mil, 14mil, etc.
LED chip structure introduction
Different LED chips are similar in structure, and have a chip substrate for epitaxial use (a sapphire substrate, a tantalum carbide substrate, etc.), a doped epitaxial semiconductor material, and a transparent metal electrode.
LED chip features
(1) The quaternary chip is prepared by the MOVPE process, and the brightness is brighter than that of the conventional chip.
(2) Excellent reliability.
(3) Wide range of applications.
(4) High security.
(5) Long life.
Important parameters of LED chips
1. Forward working current If:
It refers to the forward current value when the LED is normally illuminated. In actual use, the IF should be selected below 0.6•IFm as needed.
2. Forward working voltage VF:
The operating voltages given in the parameter table are obtained at a given forward current. It is generally measured at IF = 20 mA. The LED forward operating voltage VF is 1.4 to 3V. As the outside temperature rises, the VF will drop.
3.VI features:
The relationship between the voltage and current of the LED, when the forward voltage is less than a certain value (called the threshold), the current is extremely small and does not emit light. When the voltage exceeds a certain value, the forward current rapidly increases with the voltage and illuminates.
4. Luminous intensity IV:
The luminous intensity of a light-emitting diode generally refers to the intensity of illumination in the direction of the normal (for the axis of the cylindrical light-emitting tube). If the radiation intensity in this direction is (1/683) W/sr, then the light can be 1 candela (symbol cd). Since the intensity of the LED of a general LED is small, the intensity of the illumination is usually a candle (candela, mcd).
5. LED illumination angle:
-90°- +90°
6. Spectral half width Δλ:
It represents the spectral purity of the light-emitting tube.
7. Half value angle θ 1/2 and viewing angle:
θ 1/2 means an angle between the direction in which the luminous intensity value is half of the axial intensity value and the axial direction of the light emission (normal direction).
8. Full angle:
The angle converted from the solid angle of the LED illumination is also called the plane angle.
9. Perspective:
Refers to the maximum angle of LED illumination, depending on the viewing angle, the application is also different, also called the light intensity angle.
10. Half angle:
The angle between the normal 0° and the maximum luminous intensity value/2. Strictly speaking, it is the angle corresponding to the maximum luminous intensity value and the maximum luminous intensity value of /2. The LED packaging technology results in the maximum illumination angle not being the normal 0° intensity value, and the introduction of the deviation angle refers to the angle between the angle corresponding to the maximum illumination intensity and the normal 0°.
11. Maximum forward DC current IFm:
The maximum forward DC current allowed to be applied. Exceeding this value can damage the diode.
12. Maximum reverse voltage VRm:
The maximum reverse voltage allowed to be applied is the breakdown voltage. Above this value, the LED may be damaged by breakdown.
13. Working environment topm:
The ambient temperature range over which the LED can operate. Below or above this temperature range, the LED will not work properly and the efficiency will be greatly reduced.
14. Allow power consumption Pm:
The maximum value of the product of the forward DC voltage applied across the LED and the current flowing through it. Above this value, the LED is hot and damaged.
Summary: The main function of the LED chip is: it can directly convert electricity into light, which can be said to be the heart of LED. This article briefly introduces the basic knowledge of LED chips: the classification, structure, characteristics and important parameters of LED chips.