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  1. S

    UT61E multimeter - milliamps function not working

    It's started working again today; I don't know why. Hopefully this will be the last time I have to post to this thread.
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    UT61E multimeter - milliamps function not working

    Thanks for your response. Unfortunately the function and range switches operate as normal. I've had this multimeter only a couple of months and don't use it in a particularly dirty environment. Thanks for your response also. It was a brilliant idea! There was a resistor in series. The foil is...
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    UT61E multimeter - milliamps function not working

    I have a UNI-T UT61E multimeter and the mA function was working earlier today but now it isn't and I'm not sure why. The fuse installed is 500 mA instead of the original 1 A but that doesn't compromise protection and that fuse is not blown and I'm pretty sure I haven't subject it to more than 1...
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    Ampacity of brass/thickness of brass wire needed

    Thanks!
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    Varnish vs enamel

    Hi. Is this product the same as enamel on enamelled wires or is varnish something different?
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    Ampacity of brass/thickness of brass wire needed

    One project I'm planning will need a very high current so I'll need to use copper wire. Is there any reason I couldn't use this antique brass coloured copper craft wire and enamel it with appropriate varnish?
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    Ampacity of brass/thickness of brass wire needed

    I have a couple of LED lighting projects using brass candelabras as their base. I want to use brass wire which I will enamel using polyurethane but I need to determine with minimum width of brass wire to use. One lamp will carry up to two amps on a single wire and the other, if it goes ahead...
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    Multimeter giving bad voltage readings

    It didn't look at all dirty but I cleaned the contacts on the PCB and the knob with wire wool anyway. The screen still turns off when the dial is turned to continuity or 200 ohm resistance rage. If there's nothing else obvious then I'll probably just throw it away. Sad times.
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    What is special about solderable enamelled copper wire?

    I may have forgotten to post the URL. An enamel that disintegrates when heated sounds like a bad idea if the heat conducts far enough along the length of wire as to compromise the project. I'll stick to abrading the enamel away. Also, it's not at all evident from "solderable enamelled copper"...
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    What is special about solderable enamelled copper wire?

    This website lists their enamelled copper wire as solderable and I wanted to check whether some enamelled wires are more suitable for soldering than others? I know for sure that there are different kinds and grades of coatings but I'm not sure in what situations they matter.
  11. S

    Multimeter giving bad voltage readings

    Sorry, I didn't realise I needed to click "publish" after uploading. I hope it works now.
  12. S

    Multimeter giving bad voltage readings

    It reads correctly between 200 ohms and 47 Kohms. For some reason it reads 200 K as 120 K and 1 M as 800 K. After my attempt to recalibrate it last week, it is more correct for lower voltages and as the voltage increases, the reading seems to approach a plateau between 9 and 10 V. Since it only...
  13. S

    Multimeter giving bad voltage readings

    I've now got a functional multimeter that I might be able to use to fix the malfunctioning one. There's only one potentiometer in the malfunctioning one though. Here's a photograph of the circuit board with the fuses removed:
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    LEDs in parallel don't consume sum of individual currents??

    They were the same colour; I just don't know which colour.
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    LEDs in parallel don't consume sum of individual currents??

    The measurements in the original post were made using different LEDs and a different power supply and a different meter and I don't have access to that equipment because it's not mine (it belongs to Edinburgh Hacklab and I can only visit on Tuesday evenings without being a paying member). I also...
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    LEDs in parallel don't consume sum of individual currents??

    That's because the question has already been answered so there's no point any more. The multimeter is a Precision Gold Academy PG10B and it was set to 200 mA. It will soon be replaced with a Uni-T because it's no longer accurate and some functions cause the display to switch off. [mod...
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    LEDs in parallel don't consume sum of individual currents??

    I don't have a second multimeter at this time but in any case I'm confident that the source of the problem is indeed the multimeter. The LEDs get noticeably brighter and draw more current (measured by bench power supply) when I short the leads of the multimeter.
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    LEDs in parallel don't consume sum of individual currents??

    I understand that the currents running through different LEDs in parallel will be different for each LED due to manufacturing variations. What I don't understand is why the current isn't the same for each LED in parallel as it is when tested on its own. I was using a bench power supply and...
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    LEDs in parallel don't consume sum of individual currents??

    I think there is a misunderstanding. The ammeter was in series with the LEDs which were in parallel to each other. I expected to see about 50 mA drawn but only saw 22 mA.
  20. S

    Multimeter giving bad voltage readings

    It wasn't the battery. I've turned the calibration potentiometer all the way up or down and it still isn't correct - the readings are still too high. Maybe this is a stupid idea but I wonder whether adding resistance to the correct side of the potentiometer could improve the range enough to...
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