Author Topic: Battery charger with a blown current sense resistor. (FIXED)  (Read 1729 times)

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Offline RefrigeratorTopic starter

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Found a blown current sense resistor in my battery charger but i can't decode the colors.

Tried many online calculators but can't find one that would tell me what value brown-black-gold-grey-black is for.
« Last Edit: July 01, 2017, 11:37:12 am by Refrigerator »
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Offline bktemp

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Re: Battery charger with a blown current sense resistor.
« Reply #1 on: July 01, 2017, 08:57:57 am »
brown-black-gold -> 1 ohm
grey -> 10% tolerance
And the last black one could be something non standard, like indicating a fusible resistor.
 
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Offline Armadillo

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Re: Battery charger with a blown current sense resistor.
« Reply #2 on: July 01, 2017, 09:17:01 am »
brown-black-gold-"burn ring"-black -> 1 ohm Precision 0% tolerance. [current sense! 0.1%, 0.01% etc]
tolerance must be on the raised portion on the right side.
« Last Edit: July 01, 2017, 09:21:16 am by Armadillo »
 

Offline RefrigeratorTopic starter

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Re: Battery charger with a blown current sense resistor.
« Reply #3 on: July 01, 2017, 09:22:06 am »
I put a big fat 1R0 resistor and i'm getting 148mV across during charging, which translates to 148mA.
The charger is rated at 1.5A charge leading me to believe that the resistor is 0R1
I have a blog at http://brimmingideas.blogspot.com/ . Now less empty than ever before !
An expert of making MOSFETs explode.
 

Offline RefrigeratorTopic starter

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Re: Battery charger with a blown current sense resistor.
« Reply #4 on: July 01, 2017, 09:50:07 am »
Yes it was a 0R1, i didn't have a suitable resistor at that size so i series paralleled some smaller 0R1 resistors and also soldered some sheet metal to heatsink it.
The battery now gets charged at 1.33A, which is close enough.
I have a blog at http://brimmingideas.blogspot.com/ . Now less empty than ever before !
An expert of making MOSFETs explode.
 


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