热保护绕线熔断电阻

Add :NO.8067 West Xiang’An RD,Torch High-Tech

Industrial District, Xiang’An, Xiamen, China 361101

https://www.360docs.net/doc/4c5786245.html,

厦门赛尔特电子有限公司

Xiamen SET Electronics Co.,Ltd.

Phone : +86-0592-******* Fax : +86-0592-******* Email : sales@https://www.360docs.net/doc/4c5786245.html, Technique@https://www.360docs.net/doc/4c5786245.html,

Thermally Protected Wire Wound Resistor (TRXF )

◎This is a latest designed power resistor with over temperature and over current protection function . It can avoid the potential risk of over temperature caused by the wire wound resistor (WWR) under a small fault current.

◎SET developed a compact structure innovatively which integrated thermal cutoff and wire wound resistor in a tubular case. It has the same size and shape as a resistor without PCB redesign, offer higher security and wave-soldering.

◎Normal WWR is assembled by using alloy wire having a high melting point, it can be broken quickly only suffering more than 4X~5X rated cur-rent. While there is only a small fault current through its body, it would heat continuously and reach a rather high temperature up to 300-500℃. It will damage other components and plastic around.

◎The popular solution to this problem is to connect a thermal fuse with the WWR in series closely. Ther-mal fuse will be triggered by WWR’s abnormal over temperature. But this is not a best solution. Because thermal fuse responds slowly due to low heat transfer efficiency. So the risk of over temperature still exists. Another shortcoming is not wave soldering, occupy more spaces on the PCB.

New Fail safe fusing resistor

Series Power Resistance Thermal Link TF

Rated Current

TRXF1 1W

0.47~51Ω ±2%, ±5%, 221℃ 2A

TRXF2

3~68Ω

±2%, ±5%,

221℃

tolerance Specifications

Cautions: The fusing resistor will turn RED and reach a very high temperature up to 300~500℃ under small fault current without broken for a long time. It is very dangerous to the PCB.

UL1412/ IEC60691/UL60691

Why the fusing resistor need protection?

Normal

Turn RED

Fusing

Φd

0.56±0.2 9±1 13±1 17±1 14±1 22±2 L1

13±1 ΦD

0.43±0.2 L5

3.5±0.5 H2

19±1 H4

26±2

(mm)