可恢复保险丝的内部结构

举报
tsinghuazhuoqing 发表于 2022/07/10 00:35:25 2022/07/10
【摘要】 可恢复保险丝内部结构   §01 拆解PTR   昨天测试了这颗来自于电子宠物狗  内部电路上的可恢复保险丝, 今天使用刻刀查看一下这个器件的内部结构。...

可恢复保险丝内部结构

 

§01 解PTR


  天测试了这颗来自于电子宠物狗  内部电路上的可恢复保险丝, 今天使用刻刀查看一下这个器件的内部结构。

  # # GM1657267544_1132_707.MPG|

  下面是拆解这个课 PTR内部结构过程,这个过程的确比较缓慢,下面慢慢进行拆解。最后使用钳子夹扁PTR,它露出内部金属结构。 可以看到外部引线是直接焊接在外部金属壳上, 金属壳下面显露出黑色物质; 从侧面看,黑色物质是夹在上下两层金属片之间, 具有一定的厚度。 电流就是通过金属电极,黑色物质进行传递的。

   GM1657269027_1132_707.MPG| -6-A5

  下面在试图将两层金属片打开。 由于是金属壳,将其剥开还是比较困难的。 这是最后拆解的状态。

  GM1657269533_1132_707.MPG| GM1657272340_1280_799.MPG| #

  通过上述拆解剖析, 可以看到可恢复保险丝的基本结构, 就是在两个金属电极之间, 增加了正温度系数的物质。它的电阻随着温度增加呈现指数级别的增加。 当流过的电流加热PTC物质,引起温度升高,进而阻断电流进一步的增加。

  -5-A5

 

  结 ※


  于电子线路中使用的可恢复保险丝,本文通过拆解查看了它的基本结构。 从另外一方面也对该期间的工作原理有了进一步的了解。 这位正确使用该器件打下了基础。

  GM1657273352_1280_800.MPG| # #

一、PTC的基本应用

  如下是在 Choosing the Correct PTC Resettable Fuse 给出了使用 PTC的一些基本注意的问题:

1、确定电路参数

  The PTC selected should be able to carry the inrush current along with expected overload current spikes and normal operating current. A PTC resettable fuse is a protection device only intended to operate during overcurrent and/or overtemperature events that are not normal operation and are generally undesired conditions. They are not intended to be a switch that operates numerous times in normal operation. Treating PTC fuses as switches can cause them to fatigue if cycled too many times or held in a tripped position for extended periods of time.

  Also, a resettable PTC fuse is not a one-time fuse (or positive one-time disconnect). There still is a small amount of residual current that flows through the PTC when in a tripped position where a one-time fuse is a one-time disconnect that is designed to permanently open during an overcurrent event.

2、选择PTC

  based on the maximum ambient temperature and steady-state current. Use thermal derating graphs/charts.

3、确定阻断时间

  The time-to-trip curves are a useful tool to help determine the proper needed trip current for an application. If available, each PTC value has a colored line representing the time it takes to trip for different current values. Using the example curve in Figure 2 and following the yellow line from the top of the graph to the bottom, the PTC typically trips at the following: • 1000 seconds at 1.5 A • 1 second at 4.8 A • 0.2 seconds at 9 A • 0.03 seconds at 18 A • 0.01 seconds at 25 A

▲ 图2.1.1 阻断时间

▲ 图2.1.1 阻断时间


■ 相关文献链接:

● 相关图表链接:

文章来源: zhuoqing.blog.csdn.net,作者:卓晴,版权归原作者所有,如需转载,请联系作者。

原文链接:zhuoqing.blog.csdn.net/article/details/125679105

【版权声明】本文为华为云社区用户转载文章,如果您发现本社区中有涉嫌抄袭的内容,欢迎发送邮件进行举报,并提供相关证据,一经查实,本社区将立刻删除涉嫌侵权内容,举报邮箱: cloudbbs@huaweicloud.com
  • 点赞
  • 收藏
  • 关注作者

评论(0

0/1000
抱歉,系统识别当前为高风险访问,暂不支持该操作

全部回复

上滑加载中

设置昵称

在此一键设置昵称,即可参与社区互动!

*长度不超过10个汉字或20个英文字符,设置后3个月内不可修改。

*长度不超过10个汉字或20个英文字符,设置后3个月内不可修改。