With the same negative level transmission, when in the light, their impact on the two wires are the same, thus reducing difference at the receiving end can block this (minus operation performed can be understood as a difference of two way). It can be seen from the principle of double stranded lines that the purpose of double stranded lines is to transmit. Therefore, when we make the joint of the twisted pair, we must not separate the two different transmission lines, otherwise it will greatly affect the transmission of the network.
自承式电缆结构：导线：退火裸铜线，铜线直径为0．32，0．4，0．50，0．60，0．70，0．80，0．90mm。
绝缘材料：高密度聚乙烯或乙／丙共聚物，绝缘线的颜色符合全色谱标准。
绝缘线对：二根不同颜色的绝缘线按不同的节距扭绞成对，采用规定的色谱组合以便识别。
Integrated stranded railway signal cable implementation standard GB/ t2476-1993. Railway signal cables are suitable for transmission of railway control signals, audio signals or fixed cables for fixed installation in rated voltage ac 500V or dc 1000V or below. Product name, model, specification and scope: plastic insulation and PVC sheathed railway signal cable PTYAH; PTYA; PZYA; PTYV; PTYY,; PTY22; PTY23; (PZY02; PZY03; PZY23 PZY22) 1/0.8mm (1/1.0mm) 2-48 core is suitable for railway signal communication, fire alarm signal, telegraph and other automatic device systems with rated voltage ac 500V or dc 1000V or below. Polyethylene polythene insulation composite sheath steel tape armoured PVC sheathed railway signal cable PTYA23 PTYA22 PTY23 PTY22 PTYAH23 PZYA23 PZYA22 PZY23 PZY22 0.8 mm (1/1.0 mm) 4-61 core is fit for ac rated voltage 500 v or dc voltage 1000 v and below audio signal transmission and fixed installation of railway signal and group control automation assembly line, is of general automatic transmission railway signal, can also transmit frequency shift automatic block and business phone and other audio signal. 4, using features: cable in - 40 ℃ to + 50 ℃ environment use. Cable conductor long-term working temperature shall not exceed 70 ℃. Ordinary sheath of the cable laying under the environment temperature is not lower than 5 ℃, resistance to sheath for - 10 ℃. The bending radius shall not be less than 15 times of the outer diameter of the cable (when laying) and shall be applicable to any horizontal disturbance
RVSP屏蔽双绞线；RVSP屏蔽双绞电缆RVSP(屏蔽双绞线,屏蔽电缆,屏蔽双绞电缆屏蔽双绞铠装电缆,并可提供屏蔽双绞铠装电缆技术咨询和屏蔽双绞铠装电缆的结构尺寸屏蔽双绞铠装电缆-屏蔽双绞铠装电缆大全-专业生产屏蔽双绞铠装电缆大型企业屏蔽双绞铠装电缆-屏蔽双绞铠装电缆大全-专业生产屏蔽双绞铠装电缆.。
本厂创建于1971年，是以生产销售各类煤矿用阻燃通信电缆、矿用屏蔽电缆，矿用屏蔽通信电缆，矿用电缆，矿用屏蔽信号电缆，矿用阻燃信号电缆，煤矿用阻燃信号电缆、矿用阻燃控制电缆，煤矿用阻燃通讯电缆、矿用电缆、矿用通信电缆、矿用信号电缆、矿用通讯电缆、，矿用控制电缆，矿用监控电缆、传感器电缆、信号电缆。
三相电动机在起动时，起动电流很大，可达到额定电流的4~7倍，很大的起动电流，在短时间内会在线路上造成较大的电压降落，这不仅影响电动机本身的起动也会影响到同一线路上的其他电动机和电器设备的正常工作。
为此，对大容量电动机且起停频繁时，为了限制起动电流，必须采取降压起动。
所谓降压起动，就是在电动机起动时降低加在电动机定子绕组上的电压，当电动机转起来以后，再将加在定子绕组上的电压恢复到正常值。
由于电流与电压成正比关系，降低起动时的电压能减小起动电流。
一、产品简介本产品适用于额定电压1000V及以下对于防干扰性要求较高的电子计算机和自动化连接用电缆。
电缆地线芯绝缘采用具有抗氧化性能的K型B类低密度聚乙烯。
聚乙烯的绝缘电阻高，耐电压好，介电系数小和介质损耗温度和变频率的影响也小，不但能满足传输性能的要求，能确保电缆的使用寿命。
充油通信电缆价格|充油通信电缆直径|充油通信电缆规格|充油通信电缆芯数充油通信电缆HYAT,HYAT53,（主要技术指标）电缆芯数（规格）电缆芯径直径绝缘最大偏心(mm)绝缘抗压缩力(N)绞合节距(mm)近端串音衰减远端串音防卫度备注HYAT5×2×0.40.4050..7-119.5。
铠装双绞屏蔽型电缆 ASTP-120Ω（for RS485 CAN） one pair 18 AWG ，黑色护套，电缆外径12.3mm左右。
可用于干扰严重、鼠害频繁以及有防雷、防爆要求的场所。
MKVV 铜芯聚乙烯绝缘聚氯乙烯护套阻燃矿用控制电缆 （2-14)*(4-6) (2-61)*(0.75-2.5) 铺设在室内、电缆内、管道等固定场合。
MKVV22 铜芯聚乙烯绝缘聚氯乙烯护套钢带锴装阻燃煤矿用控制电缆 (7-61)*(0.75-1.5) (4-14)*(4-6) 铺设在室内、电缆内、管道、直埋，能承受较大机械外力的固定场合。
铜芯聚乙稀绝缘聚氯乙稀护套铜丝编织屏蔽计算机电缆规格导体种类绝缘标称厚度mm编织单线直径mm外护套标称厚度mm电缆外径≤mm硬导体软导体1x2x0.7510.60.151.48.29．41x2x1.010.60.151.48.710．11x2x1.51。
也可提供双层护套的通信电缆。
MHY32（PUYV×21×42×23×24×25×26×28×210×2）1/1.0、1/1.38聚乙烯绝缘钢丝铠装聚氯乙烯护套煤矿用信号电缆用于平巷或竖井或斜井作信号传输。
，用户给定的最高工作频率fmax＝120Hz，频率精度为0.01%，则最大误差为：Δfmax＝0.0001×120Hz＝0.012Hz通常，由数字量给定时的频率精度约比模拟量给定时的频率精度高一个数量级，前者通常能达到±0.01%（-10～＋50℃），后者通常能达到±0.5%［（25±10）℃］。
频率分辨率指输出频率的最小改变量，即每相邻两挡频率之间的最小差值。
，当工作频率fx＝25Hz时，如果变频器的频率分辨率为0.01Hz，则上一挡的最小频率为：fn′＝（25＋0.01）Hz＝25.01Hz下一挡的最大频率为：fx″＝（25－0.01）Hz＝24.99Hz对于数字设定式的变频器，频率分辨率取决于微机系统的性能，在整个调频范围（如0.5～400Hz）内是一个常数（±0.01Hz）。
MHYVP 2 * 3.3+2 * 0.85 data for mine shielded communication cable 1. Tin coated copper wire is used for conductor, 47/0.3 for conductor, 12/0.3 for 0.85, and 7/0.28 tin coated copper wire for drainage line. 2. Insulation color: 3.3 the wire core is a red one and a blue one, while the 0.85 wire core is a white one and a green one. The white wire core is wrapped with aluminum foil. 3. Insulation thickness: 3.3 core insulation thickness is 0.5, and the outside diameter after insulation is 3.5 mm. The insulation thickness of wire core is 0.7 and the outside diameter after insulation is 2.5mm. 4. Into line with the four wire core is arranged for red, green, blue, white, streamline, and row streamline to conductors are twisted together, don't put longitudinal, are not added when cabling filler, external use aluminum foil winding and cable core, then a layer of polyester film around the package, the outside is a layer of copper wire braided shielding (shielded copper wire tin plating). 5. Sheath: the front diameter is 8.2mm, the back diameter is 12mm (between 11.7mm and 12mm), and the sleeve is flame retardant blue
电缆型号、名称、规格及用途型号名称规格用途MHYV（PUYV）聚乙烯绝缘阻燃聚氯乙烯护套矿用信号电缆2-57/0.28用于平巷、斜巷及机电耍硐室MHJYV（PUJYV）聚乙烯绝缘阻燃聚氯乙烯护套加强矿用通讯电缆2-57/0.28(三钢四铜)用于平巷、斜巷、有较好的抗拉强度MHYVP。