Annealed bare copper wire for the structure of mining communication cable, copper wire diameter is 0.30, 0.42, 0.52, 0.60, 0.70, 0.80, 0.90 (mm). The insulating material is high-density polyethylene or polypropylene, and the color of the insulated wire is marked according to the full chromatographic standard. Insulated wire pairs Twisted two insulated wires of different colors at different pitches, and used the specified chromatographic combination to identify the wire pairs. The core structure of the communication cable takes 1 pair as the basic unit, and more than 25 pairs of cables are combined in units, and each unit is wrapped with a unit cable tie of the specified chromatogram to identify different units. Cables of 100 pairs and above have a 1% reserve pair, but no more than 6 pairs. The gap in the cable core is filled with petroleum paste. The cable core tape is wrapped with polyester film tape. Shielding copper wire shielding or rolling (or not rolling) metal tape, the metal tape is longitudinally wrapped outside the core tape of the communication cable. Sheath blue low density polyethylene. Communication cables with double jackets are also available. Identification and Length Marking of Mine Communication Cables There is a permanent identification mark on the outer surface of the cable. The marking interval is not more than 1m. The marking content includes: wire diameter, number of pairs, cable model, manufacturer's name code and year of manufacture, and the length mark is The interval is not more than 1m marked on the outer surface, but staggered from the above mark. The mining communication cable adopts full chromatographic insulation and an aluminum-plastic composite sheath (that is, the longitudinal shielding aluminum tape of the cable is bonded to the sheath to form a sealed sheath), which has the characteristics of superior electrical performance and convenient construction. The cause of fire caused by mining communication cables is mainly due to overload, short circuit, excessive contact resistance and external heat source. Under fault conditions such as short circuit, local overheating, and external heat, the insulation resistance of the insulation material drops, loses its insulation capacity, or even burns, which in turn causes a fire. The main characteristics of mining cables in fires are that the fire temperature is generally 800 ℃ ～ 1000 ℃. In the event of a fire, the conductor cable will quickly lose its insulation capacity, which will lead to secondary electrical accidents such as short circuit, causing greater losses; conductor cable Under the specified allowable current carrying capacity, there is a large overload capacity; under short-circuit conditions, the wire and cable will cause the insulating material to melt and burn in an instant, and ignite the surrounding combustibles. Fire resistance analysis of mine cables Fire resistance mechanism analysis Flame retardant mechanism Under the heat of combustion reaction, the flame retardant located in the condensed phase decomposes and absorbs heat, which slows down the temperature rise in the condensed phase and delays the thermal decomposition rate of the material; flame retardant After the agent is thermally decomposed, it releases a chain reaction free radical blocker, which interrupts the flame and the chain reaction branch, slowing down the gas phase reaction rate; the thermal decomposition of the solid phase product by the catalytic condensate phase, the formation of the coking layer or foam layer strengthens these layers The shape of the hard shell hinders the heat transfer; under the action of heat, the flame retardant undergoes an endothermic phase change, which physically prevents the temperature in the condensed phase from rising. Fire resistance mechanism Add some additives to the insulation and sheath materials of mining cables, reduce the heat generated by the polymer, prevent the polymer from decomposing or promote the carbonization of the insulation and sheath materials to form a protective layer; add a layer of mica glass ribbon at the core of the wire For inorganic insulating materials, after the insulation and sheath are eroded by fire, the mica refractory tape wrapped around the conductor is protected and continues to be energized, so as to maintain normal operation for a certain period of time in the event of fire.
Headphone Speaker:
Headphone speaker is a king of speaker unit which is used for headphone, it also called headphone driver. These speakers have high sound pressure level, fast frequency response, wide frequency response range and low distortion. Headphone Speakers are mainly used for voice headphone (e.g. customer service phone, call center headphone, military intercom headset- ) and music headphone (e.g. Bluetooth headphone, sport headphone, game headphone-).
Our main headphone speakers include:
1) From the diameter, we have speakers in 23mm ~ 57mm.
2) From the impedance, we have speakers of 32ohm/150ohm/300ohm/1000ohm.
FAQ
Q1. What is the MOQ?
XDEC: 2000pcs for one model.
Q2. What is the delivery lead time?
XDEC: 15 days for normal orders, 10 days for urgent orders.
Q3. What are the payment methods?
XDEC: T/T, PayPal, Western Union, Money Gram.
Q4. Can you offer samples for testing?
XDEC: Yes, we offer free samples.
Q5. How soon can you send samples?
XDEC: We can send samples in 3-5 days.
Music Headphone Speaker
Bluetooth Headphone Speaker,Sport Headphone Speaker,Hifi Headphone Speaker,Music Headphone Speaker
Shenzhen Xuanda Electronics Co., Ltd. , https://www.xdecspeaker.com