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Thread: resistor value

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    Default resistor value

    Hi All,
    I have small issue when repair . I found this blow up and can not use LCR to measure value . I think this just few ohm. but I cant reach the color code .anybody know this please help
    55831581_325206234858451_4270825559707090944_n.jpg
    thank you

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    Default

    That should be a 280 kΩ 1%

    Can't really guarantee I'm correct, probably best if you wait for a couple more answers
    Careful what you wish for... You just might get it.

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    asf14tomcat (04-03-2019)

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    Default

    this resistor sit after bridge diode. I think function like currents shunt resistor . but shunt resistor just below <0 ohm .
    because this blow up and open circuit so I cant measure this
    the funny is the silver brand sit in 3rd . how can calculate ?

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    replaced some part . Change the stock unknown resistor with some shunt resistor I have
    light it up!
    20193d37bc40-bf7a-4b4d-981d-eaf8a884af46.jpg
    d1354de7377ed5208c6f.jpg
    lets do some load test before send it back for my customer . I hope this can survive ~400W test. but I think the OPP will not work accurate. that's a old toys
    Last edited by asf14tomcat; 04-03-2019 at 09:43 AM. Reason: picture

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    CX500, Johnny should be able to tell you.

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    i think a few mili volt . not measure yet. research datasheet of cm6800 series . in the schematic it look like R18

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    Default

    The schematic doesn't give the value?

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    nah . depend max power, % PWM duty, frequency. you want and caculate the value
    . if you want something more detail . lets search datasheet of CM6901 . they give you all . and some manufacture design same as schematic from champion .
    btw. in datasheet of CM6901 they call this resistor is : "high inrush curent resistor" and one way connect with Isens pin of IC . maybe this use for soft start like NTC ?

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    If one reads it as a 4 band one gets 0.14 Ohm

    Now one might expect it to carry maybe 4 amp at full load (after the surge);
    that gives about 2W dissipation

    seems about right


    What resistance did you put in?

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