Thermal fuse/ printed circuit fuse

[Willie9240]

Hey I have this thermal cutoff fuse and I want to find a replacement.

But if I can find a data sheet or spec sheet with your help that’s all I need to find a compatible fuse to use.

The fuse has this printed:

A-YX01
E478338
ru 94V-0
HRS2057-C
16.05.08

Thanks in advance

[kb5zue]

I just did a google search on the fuse A-YX01 and  HRS2057-C and found a bunch of websites containing information that you can use.  It's what called a thermal strip fuse and is pretty common.  The 16.05.08 is the date of manufacture.

[mariushm]

Well, not sure you'll find that easily, you'll find more complicated things that do the same stuff.

 

The basic operation of that device is that the metal on the circuit board has some resistance which means that when electricity goes through it, the metal heats up and when that metal heats up enough it melts and opens up.

 

In this other thread, I see this thing used to break if a device was left running for more than 10 minutes, which makes me think the copper trace needs to exceed around 100c for the metal to break apart - for reference the solder on the circuit board would melt at 183c for leaded solder and 217c+ for unleaded solder.

 

You could probably replicate the functionality by gluing a thermal cutoff above a low value resistor and running the power through both (in series). when the resistor overheats, the thermal fuse would break interrupting the circuit.

The problem will be choosing the resistor value so that it will slowly warm up to the the threshold temperature in the same amount of time, because how fast the resistor will heat up will depend on how much current it goes through it.

Actual thermal fuses you can get with various temperature thresholds, here's link : https://www.digikey.com/en/products/filter/thermal-cutoffs-thermal-fuses-and-breakers/146?s=N4IgTCBcDaIC4AsCmAnAtgQwDYAIBmArgM5IgC6AvkA

As for resistors ... like I said, the value would vary depending on how fast you want to heat up... basic math for example P = Current ² x Resistance .. so if you want 10A to go through the wire and you pick a 0.01 ohm resistor, then you're gonna have P = 10x10x0.01 = 1 watt

The resistor will heat up gradually, and how fast will depend on how thick the traces going to it and the wires will be as some heat will dissipate through that.

Here's an example of such resistor  : https://www.digikey.com/en/products/detail/ohmite/MCS1632R010FER/2003858

 

[Willie9240]

Thanks that’s all I needed to pick the right one to replace it.