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    Unknown device in a high voltage chopper

    Hello,
    I am curious to know what are the circled devices.
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    Thanks

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    Re: Unknown device in a high voltage chopper

    Zero ohm resistor.
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    Re: Unknown device in a high voltage chopper

    certainly appears to be a zero ohm link and not a typical ferrite bead ...


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    Re: Unknown device in a high voltage chopper

    Not a typical ferrite bead form, but may be ferrite beads though.

    You'll check the material around the wire.


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    Re: Unknown device in a high voltage chopper

    Hi,

    This thread from Electro-Tech-Online.com says in the first answer: "If possible also name them on the PCB like "BR1" (BR=German abbreviation for jump or bridge)".

    All others I saw said BR = bridge rectifier.

    My zero Ohm resistors are (typical) light blue ones with a black stripe across the middle and measure from 3 to 7 milliOhms (I'm that sad I actually measured 10 of them out of curiosity when they arrived). IMHO, I'd measure them, anything under ~10mOhms is presumably a zero Ohm resistor.

    There was a similar/identical thread here on EDA in January 2018, Parts name identification BR in PCB.

    Is the PCB of German origin or design?


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    Re: Unknown device in a high voltage chopper

    @d123
    If you look at the photo, ypu will notice one BRIDGE unpopulated (it has dashed line on silk between pads). Definetly it is a piece of wire suitably placed in a piece of some material to resemble a 0 ohm resistor (one black stripe). Body color does not matter, it is dependent on manufacturer.

    If you want to measure your 0 ohm resistors, connect as many as you can in series and measure resistance. The more of those in series, it will be easier to determine the resistance (unless you have quite expensive microohm meter).
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    Re: Unknown device in a high voltage chopper

    Hi there,

    Quote Originally Posted by ZASto View Post
    @d123
    If you look at the photo, ypu will notice one BRIDGE unpopulated (it has dashed line on silk between pads). Definetly it is a piece of wire suitably placed in a piece of some material to resemble a 0 ohm resistor (one black stripe). Body color does not matter, it is dependent on manufacturer.

    If you want to measure your 0 ohm resistors, connect as many as you can in series and measure resistance. The more of those in series, it will be easier to determine the resistance (unless you have quite expensive microohm meter).
    Thanks, I was only pointing out that a lot seem to be pastel blue, nothing else.

    Also, "quite expensive"? How about homemade, cheap-and-nasty-looking with no enclosure and consistently over 99% accurate? Photos for your pleasure - and look at how horrible the hand-made pcb is - done with a cutter and a very, very sharpened Philips screwdriver and even better, a 7106 as the ADC, but the constantly accurate numbers don't lie, though I guess someone will jump to disagree about how reliable it is for the sake of it. I have made some epic fail circuits, some not great ones, some that are okay and a couple that I am modestly proud of, this little monster is one of them, even with one poor solder joint on one LCD segment pin:

    Click image for larger version. 

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