• 服用-热门标签-华商生活 2019-05-25
  • 浙江检验检疫局积极推进出口水产品HACCP认证示范区建设 2019-05-25
  • 中日韩三国记者“环保行”联合采访——韩国 2019-05-24
  • 南昌未来三天有连续性降雨 最高气温均在30℃以上 2019-05-24
  • 估计明天就可以吃上端午节的菜了。 2019-05-23
  • 黑龙江严肃对待督察整改工作 2019-05-23
  • 第九届海峡两岸文化创意产业展在台北开幕 2019-05-23
  • 白云区图书馆:来,给爸比做张甜蜜立体感恩卡 2019-05-22
  • 用脚步丈量城市,全国20城奔向美好生活 ——凤凰网房产北京 2019-05-22
  • 进编制、最好是提干、这依然是大家的就业选择。公有制体制面临大革命了。有效释放进入体制享福的劳动力。 2019-05-22
  • 今晚暴雨预警!端午过后除了世界杯还有梅雨等着你 2019-05-22
  • 《人民日报》创刊70周年 各界人士送祝福 2019-05-21
  • 暑期档:国产战场史上最强 海外战场续集当道 2019-05-21
  • 回复@老老保老张工:吃个早餐还要让人批准?就这点出息啊? 2019-05-21
  • 光明日报:让偷话费的“影子服务”无处藏身 2019-05-21
  • Research

    北单5串1全包:For knowledge, for competitiveness and for fun.

    The Challenge: PTC and Self-regulating Cable

    PTC Explained

    哪个app可以买北单 www.lazyf.tw A polymeric PTC(positive temperature coefficient) material comprises a non-conductive polymer matrix that is loaded with carbon black particles to make it conductive.

    While cool, the polymer is in crystalline state, with the carbon latched into the regions between crystals, forming many conductive chains.  If electric power is applied, current will pass through the polymer and generate heat, which causes the polymer to expand.  The expansion separates the carbon particles and gradually breaks some of the conductive chains, causing the resistance of the device to increase.  

    PTC curveAs the polymer heats up to certain temperature, it changes from crystalline state into amorphous state and breaks most of the conductive chains.  The dramatic increase in resistance substantially reduces the electric current.  A small current still flows through the polymer and is sufficient to maintain the temperature at a level which will keep it in the high resistance state.  When power is removed, the heating will stop.  As the polymer cools, it regains its original crystalline structure and returns to a low resistance state.

    Self-regulating Heating Cable

    SR structure

    Self-temperature regulating cable consists of two parallel metal bus wires encased in PTC polymer matrix forming a heating unit with a polyolefin insulation and metallic braided shield.  For corrosive and some hazardous environments, additional fluoroplastics overjackets will be applied.

    SR outputAs the electric current flows from one of the copper wires, passes through the conductive polymer and arrives in the other copper wire, a close circuit is established.  The electric power causes PTC polymer to heat up and gradually raises the resistance value.  As the temperature of the conductive core increases, so does the electrical resistance.  The result is a diminishing output for each temperature increment.  In other word, self regulating heating cables adjust their power output in response to the surrounding temperature, in comparison with constant wattage heating cables that give out constant output to the heated objects.  

    Once the PTC polymer reaches the transition temperature, its resistance value takes a step increase, which is high enough to almost cut off the current and keep the temperature from going any higher, and the purpose of self-temperature regulating is served.

    Epoly manufactures all PTC compounds in-house.  We believe strongly that this is the only way to maintain the highest quality finished self-regulating cable products. 

    The Advantages and Disadvantages of Self-regulation Heating Cable

    Advantages

    • Ensure the temperature of object heated constantly stays within an ideal range.
    • Can be overlapped without the risks of overheating or burnout.
    • High electro-thermal conversion rate. Even heat distribution. Low energy consumption.
    • Self temperature regulating and self heat output regulating.
    • Can be cut to any length. Systems are easy to design and install.
    • Its tendency to reach a limiting temperature means safety.

    Disadvantages

    Self-regulating heating cables have a specific maximum exposure temperature based on the type of polymer which is used to make the heating core (PTC) which means that if they are subject to high temperatures then the cable can be damaged beyond repair.  Also self-regulating cables are subject to high inrush currents on starting up similar to 'induction' motor so a higher rated circuit breaker is required.

     

  • 服用-热门标签-华商生活 2019-05-25
  • 浙江检验检疫局积极推进出口水产品HACCP认证示范区建设 2019-05-25
  • 中日韩三国记者“环保行”联合采访——韩国 2019-05-24
  • 南昌未来三天有连续性降雨 最高气温均在30℃以上 2019-05-24
  • 估计明天就可以吃上端午节的菜了。 2019-05-23
  • 黑龙江严肃对待督察整改工作 2019-05-23
  • 第九届海峡两岸文化创意产业展在台北开幕 2019-05-23
  • 白云区图书馆:来,给爸比做张甜蜜立体感恩卡 2019-05-22
  • 用脚步丈量城市,全国20城奔向美好生活 ——凤凰网房产北京 2019-05-22
  • 进编制、最好是提干、这依然是大家的就业选择。公有制体制面临大革命了。有效释放进入体制享福的劳动力。 2019-05-22
  • 今晚暴雨预警!端午过后除了世界杯还有梅雨等着你 2019-05-22
  • 《人民日报》创刊70周年 各界人士送祝福 2019-05-21
  • 暑期档:国产战场史上最强 海外战场续集当道 2019-05-21
  • 回复@老老保老张工:吃个早餐还要让人批准?就这点出息啊? 2019-05-21
  • 光明日报:让偷话费的“影子服务”无处藏身 2019-05-21