I got this resistor that I need help in obtaining its value

[Canada EH]

Its five colors with the first and last known 100%

 

Green is confirmed color

Grey or black or silver

Grey or black or silver

Grey or black or silver

Black is confirmed color

 

I can only assume since black has no tolerance that black is the first #

Green is 5 or 0.5%

And I am guessing theres a good change the last three are grey grey black.

 

 

 

 

[Enderman]

Why not just measure it...?

[Canada EH]

1 minute ago, Enderman said:

Why not just measure it...?

I cant, its damaged

[billstelling]

[Enderman]

Just now, Canada EH said:

I cant, its damaged

How?

It doesn't look burned up.

[Enderman]

Just now, billstelling said:

 

Try reading the post again.

His issue is not determining what the value of each colour is.

[Canada EH]

5 minutes ago, Enderman said:

How?

It doesn't look burned up.

Yeah it burnt up

I believe is open as a continuity test doesnt beep

I think its very small resistance which wouldnt come up on my dmm which would read 0.1 ohms or 100mOhms

even probes on resistnace shows open

 

Also a ZERO (BLACK) for a starting digit?

https://electronics.stackexchange.com/questions/171289/4-5-band-resistor-extra-black-band

Quote

Divide those numbers by 10 because of the leading zero.

 

[Canada EH]

grey grey white

8 8 9-nine zeros too many

because the two last ones look the same color and the first is a bit lighter

 

grey grey brown

8 8 1 = 880ohms

[billstelling]

10 minutes ago, Enderman said:

Try reading the post again.

His issue is not determining what the value of each colour is.

It was for reference..

 

You have the important part and should be able to find a like one on the board you can use as a baseline to guess what it is. Also, with the old stuff you can be off a bit if you are in the correct range and things will work just fine with no ill effect. You can also "tune" older stuff that use such parts with different variables by replacing or upgrading some components. Different values.. In some cases you can bypass a resistor and the component will work as they are used to tune the flow and usually in very small ways.

 

You should be able to guess the correct one based on the other ones used on the board like I said though...

[Canada EH]

It is for an RC charger, everything works except the discharging brings up an error, and its near a wire wound resistor which makes sense for discharge current.

 

 

first black, divide by 10

NO => grey grey white = 88,000,000,000 divided by 10 = 8.8Gohm

NO => grey grey grey = 8,800,000,000 divided by 10 = 800Mohm

Best Guess => grey grey brown = 880 divided by 10 = 88ohms

Dunno => grey grey black = 88 = 8.8ohms

 

 

[Guest]

I wouldn’t know which way to read it. 

From my DC circuits class my teacher said all (at least in America) resistors have a silver or gold band at one end, and that’s the final color in the number to rate percent error. 

 

Unless there were other colors and this is just a really old or obscure resistor, I’m sorry. 

[Unimportant]

17 hours ago, Canada EH said:

Its five colors with the first and last known 100%

 

Green is confirmed color

Grey or black or silver

Grey or black or silver

Grey or black or silver

Black is confirmed color

 

I can only assume since black has no tolerance that black is the first #

A leading black ring is sometimes used for very small resistor values. It means you should divide the resistance value by 10. A black ring is indeed never used for tolerance.

Sadly, without the missing rings it's impossible to come to any sensible conclusions.

 

Perhaps try drawing out a schematic of the circuit it came from and work out what value it should be ?

 

[billstelling]

Might be able to find the service schematic for it somewhere.

 

Being what it is for, the discharge port, It is more than likely just to set the output amps and would be fine as long as you are close. Check the output with a meter and go from there. Should take one try and that reading to be able to do the math and figure out the correct one, or damn close at any rate. It's just dropping the output rate to were in needs to be.

Bypassed with a jumper it should work, just over specs..

[Canada EH]

The only solution to my problem is to find someone with the same device, who is willing to open it up and visually inspect the color code.

Now that I think about it, its probably very similar to other chargers in the same discharge amount, like the 6S models. I was thinking about buying a 6S clone for cheap for discharging, and having that would enable me to balance charge more series strings, totalling 14S, and currently my pack is at 13S so I may go that route.

 

This is a hobby charger meant for very little discharge wattage, but its still nice to have.

The charging aspect of the device works fine.

 

What happened was I was doing something (cant remember what, charging something obvisouly) and a puff of smoke came through the fan, I was lucky that I caught it when I did because it lasted maybe a handful of seconds before it disapated. I'd sure like to find a video on someone burning resistors and seeing the smoke characteristics. Anyways it still worked fine charging, then a ways later when I wanted to decrease the voltage a bit on my pack, of course the error popped up on the screen. Naturally I opened it up and tried to find obvious signs, which I did, in that resistor.

 

 

[Unimportant]

21 minutes ago, Canada EH said:

Anyways it still worked fine charging, then a ways later when I wanted to decrease the voltage a bit on my pack, of course the error popped up on the screen. Naturally I opened it up and tried to find obvious signs, which I did, in that resistor.

So it is part of the discharge circuit. It's unlikely to be the actual discharge load, it's too puny a resistor. My guesstimate: It's a current shunt for measuring the current trough the actual load. 

 

Does the device display the discharge current on the display while it's discharging ? If so, you can try installing a random ballpark figure resistor. Then you can use the discharge current being displayed, the actual current (measured with multimeter) and ohms law to calculate what the correct resistance value should be.

[Canada EH]

You are right on that, the load resistor is a wire wound resistor, 5W 0.02ohm with whatever J means for tolerance. Its just a bit bigger then a Chicklet gum piece. It starts discharging, meaning its going through the process of starting it up, but once its starting the error comes up. I have narrowed the colors down to either grey grey brown 88ohms inc. 10 divider. or grey grey black 8.8 ohms. Do those values make sense?

 

11 minutes ago, Unimportant said:

So it is part of the discharge circuit. It's unlikely to be the actual discharge load, it's too puny a resistor. My guesstimate: It's a current shunt for measuring the current trough the actual load. 

 

Does the device display the discharge current on the display while it's discharging ? If so, you can try installing a random ballpark figure resistor. Then you can use the discharge current being displayed and ohms law to calculate what the correct resistance value should be.

 

[Unimportant]

8 minutes ago, Canada EH said:

Do those values make sense?

8, 8 is not part of the E12 series so it's less likely, but resistors outside the E12 series exist so it's not impossible.

Although, judging from the picture, it's badly burnt. Any color looks grey when burnt so it's all just guess-work.

[Canada EH]

3 hours ago, Unimportant said:

8, 8 is not part of the E12 series so it's less likely, but resistors outside the E12 series exist so it's not impossible.

Although, judging from the picture, it's badly burnt. Any color looks grey when burnt so it's all just guess-work.

Yeah I will have to take a look at common resistor ohmic values.