灯具用延时启动型热敏电阻器 

产品特点： 

随着对于节能的需求，用于电子镇流器软启动的热敏电阻器越来越受到大家的重视。传统的镇流器启动，未经预热突加高压灯丝材料会发生严重溅射损耗，导致灯管提前发黑报废。而用热敏电阻器做延时启动的镇流器，是经过预热再加高压点亮灯管的，灯丝材料只会产生极其轻微的溅射，从而大大延长了灯管的寿命。有关机构所作的试验表明：应用PTC热敏电阻器来做延时启动，可以改变电子镇流器、电子节能灯的硬启动为预热启动，灯丝的预热时间达0.4-2.0秒，这样的电子镇流器能使灯管寿命延长四倍以上。

工作原理

当高频震荡回路接通时，由于PTC处于冷状态，Rt处于低阻状态，其阻值远远低于C2阻值，此时灯管电压小于它启动所需的电压值。于是，电流通过C1、Rt形成回路预热灯丝。与此同时，PTC热敏电阻也被加热到居里温度以上，Rt发热温度超过开关温度Tsw跃入高阻状态。其阻值远远高于C2阻值，电流则通过C1、C2形成回路导致LC谐振，产生高压点亮灯管。一般情况下延长预热时间应选用阻值较低、居里点较高、体积较大的PTC热敏电阻器。 

主要应用：

产品主要应用于荧光灯电子镇流器，电子节能灯中。 

Delay-Time PTC Thermistors for Lamps and Lanterns

   Features of Products:

With the development of global energy conservation, PTC Thermistors for electronic ballast softly starting has attracted more and more public attention. The traditional ballast starting, added high-pressure filament material suddenly without preheating, will take serious sputter and loss, and make the light turn black and scrap ahead of time. However, the electronic ballasts we have researched and developed, have been through preheating and high pressure. Lighting the tube, the filament material can only produce slight sputter, and can extend the light life span greatly. Tests by some authority organizations have indicated: Using PTC Thermistor to delay starting, can change the hard starting to pre-heating starting of the electronic ballasts and electronic power-saving lamps. The pre-heating time of wires can reach to 0.4-2.0 seconds. Such electronic ballasts can make the lamp service prolonged to more than 5 times.

Working Theories:

When the high frequency shaking return circuit has been put through, and because PTC is in a cold state and Rt is in a low state of resistance, its resistance value is far lower than that of C2, and the light pressure is smaller than that of starting it. Then current through C1, RT forms the return circuit-preheating filament. Meanwhile, PTC Thermistor is heated to above the Curie temperature, Rt heating temperature exceeding the switch temperature TSW and leaping to the state of high resistance too. Its resistance value is far higher than that of C2, and the current goes through C1, C2, forming the return circuit and causing LC resonance and producing high pressure and lighting the tube. Generally speaking, to delay the preheating time, we should select the relatively lower resistance, taller Tc point and bigger PTC Thermistor.

Main Applications

 Products are mainly applied in fluorescence lamp electronic ballasts, electronic power-saving lamps, and triggers.