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Weird fuse resistor

C

Christoph34

Junior Member
Hi guys, I've check my computer's power supply and noticed that it has some Fuse resistor in bad shape, but can't find nowhere the value of the resistor, so I thought that some of you might know

the fuse resistor is in the Power supply and it color code is;

Brown - Black - Silver - Gold - Black

the fuse resistor's body is color Pink if that has something to do with it...
 
xfZSpB0.png


Body Color won't effect the resistance value, but it might indicate some special specification about temperature or stability.
 
Per the above resistance color code chart in videogames101's post:

Brown - Black - Silver - Gold - Black = 10 x 0.1 = 1.0 ohms, 5% tolerance

The other spec you'll need is the power rating for the resistor, which determines how much power it will handle before blowing. You can determine the power rating by the size of the part.

For example, Digi-Key has this Yageo fusible resistor rated at 1/2 watt. The dimensions are 0.094" diameter x 0.248" long.

This fusible resistor is rated at 1 watt. The dimensions are 0.177" diameter x 0.453" long.

You can use this selector page to find the part you want at the rating you require.

Note that not all models are available as single pieces so you may have to shop elsewhere to find a vendor who sells small quantities, but this should help you define the part(s) you need.

videogames101 said:
Body Color won't effect the resistance value, but it might indicate some special specification about temperature or stability.
Click to expand...

It may also indicate the materials used in the fuse resistor. The Yageo parts at the above links are wire wound resistors. There are other technonolgies, including metal film fusible resistors and those with special flameproof coatings, and the body size for different power ratings will vary for each type. For more info, see this datasheet for Vishay's CMF line of flameproof metal film fusible resistors. See this selector page for more info about Vishay's other fusible resistor products.

Hope that helps. 🙂
 
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Harvey said:
Per the above resistance color code chart in videogames101's post:

Brown - Black - Silver - Gold - Black = 10 x 0.1 = 1.0 ohms, 5% tolerance
Click to expand...

I was actually a little confused because that code didn't quite match the chart. I was wondering if by silver he meant grey for an oddball 10.8 Ohm resistor, but then black for the tolerance band isn't defined?
 
videogames101 said:
I was actually a little confused because that code didn't quite match the chart. I was wondering if by silver he meant grey for an oddball 10.8 Ohm resistor, but then black for the tolerance band isn't defined?
Click to expand...

Oops! I misread the chart. 😳 The line should have read:

Brown - Black - Silver - Gold - Black = 10 x 0.01 = 0.1 ohms, 5%

The final black line could be a temperature coefficient.

Correcting info in the rest of my previous post:

Digi-Key has this Yageo 0.1 ohm fusible resistor rated at 2 watts. The dimensions are 0.197" diameter x 0.610" long.

You can use this selector page to find the part you want at the rating you require.
 
Nope

is as follow, Brown - Black - Silver - Gold - Black , silver, not grey, and yes, If it was Grey should be 10.8, but is not


so is Brown - Black - Silver
1 0 x 0.01 = .1 ohm

but

someone, that I could say is expert in this thing told me that i 1.0 ohm like reading as follow

Brown - Black - Black - silver
1 0 0 x 0.01 = 1 ohm


I used a program with slectable colors that said that is 1 ohm, as the Silver color cannot be choose until the multiplier meaning the 4 strip, gold as tolerance and the last black as temperature coefficient...


besides that this expert guy knew and told me that this fuse resistors goes in the power supplies of the electronics without me telling that the resistor was from my power supply
 
Computer power supplies generally don't use any leaded resistors in a fuse capacity, nor does any other remotely modern anything that I can think of. It's just too unreliable a design as it will tend to delaminate the PCB traces and melt solder by the time the resistor itself breaks.

On the other hand if it were metal film and surface mount very low ohm then yeah, could be a cheap fuse but usually on the upstream portion of a DC-DC product, or a low current output, not as likely an AC-DC computer power supply.

Perhaps it would help if you took a good picture of the PSU and indicated where this resistor is in it, not just to clear up the what's-its-function angle but also because there is likely something else that caused it to fail, that it's not so simple as just replacing the resistor without repairing the cause for the excess current across it.
 
I'm seeing two or three different resistors pictured and one looks more like red black sliver gold not brown black silver gold. If it's getting hot the red may darken some, or maybe it's your lighting or my monitor calibration or whatever but it looks more like red than brown to me.

You may be able to read the resistance value with a multimeter, in or possibly necessary to take it out of circuit if you really want to pursue this but since you wrote that the psu isn't damaged yet, I don't understand the point of this exercise. If it merely discolored a bit, sure, power resistors do that.

Anyway I can't make heads or tails of those pics but these don't look like they're intended to be resistors as fuses. There should be a real fuse upstream from them and there's also what looks like a NTC thermistor (green disc) for current limiting in the 2nd pic.

If all else fails then flip the PCB over and trace the circuit, see what they're connecting.
 
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mindless1 said:
I'm seeing two or three different resistors pictured and one looks more like red black sliver gold not brown black silver gold. If it's getting hot the red may darken some, or maybe it's your lighting or my monitor calibration or whatever but it looks more like red than brown to me.

You may be able to read the resistance value with a multimeter, in or possibly necessary to take it out of circuit if you really want to pursue this but since you wrote that the psu isn't damaged yet, I don't understand the point of this exercise. If it merely discolored a bit, sure, power resistors do that.

Anyway I can't make heads or tails of those pics but these don't look like they're intended to be resistors as fuses. There should be a real fuse upstream from them and there's also what looks like a NTC thermistor (green disc) for current limiting in the 2nd pic.

If all else fails then flip the PCB over and trace the circuit, see what they're connecting.
Click to expand...



yes, actually I see the "brown" as red, but my friend sees it brown, eitherway is gonna be 0.1 ohm or 0.2 ohm with 225 ppm in thermal coefficient
 
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