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USB Power Current Voltage Detector $0.76 US ($0.99 AUD) - Sledge Hammer Metal 3D Puzzle $0.87 US ($1.14 AUD) Shipped @ GearBest

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70%OFF$1

Couple of Cheapies from Gearbest - code works for both items in the same cart

Enjoy!

USB Power Current Voltage Detector

Main Features:
- Compact design, easy to take and test the USB port's output voltage and working current
- Plug and play, the voltage and current will show in turn on the display
- Adopted the new generation integrated circuit, high accuracy, stable operation, best anti-interference
- Suitable for mobile charger, USB disk in factory, lab and personal use

Specifications:
Model: KW201
Working range: 3 - 7.5 V, 0 - 3 A
Resolution: 10mV, 1mA
Error: Voltage less than + / - 1pct, current less than + / - 2pct
Full range voltage drop: 200mV ( current detecting )
Working temperature: 0 - 60 Deg.C


3D Sledge Hammer Style Metal Puzzle

Main Features:
• When opened the package, it's just a metal plate
• You only need to according to the instructions simple bending, folding, assembly, then the plate can become a very delicate 3D model, without using glue
• Stainless steel material
Specification
General Information
Type: 3D Puzzle
Gender: Unisex
Theme: Other
Style: Other
Materials: Other
Stem From: China
Dimensions and Weight
Product weight: 0.0500 kg
Package weight: 0.0600 kg
Product size: 8.30 x 8.30 x 4.50 cm / 3.27 x 3.27 x 1.77 inches
Package size: 17.00 x 12.00 x 0.20 cm / 6.69 x 4.72 x 0.08 inches
Package Contents
Package Contents: 2 x Metal Plate, 1 x Manual ( Pure Graphic, Used Universal, No Chinese or English )

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closed Comments

  • +8

    I got one of the meters some time ago. It's not bad, tells me how much current my devices draw when charging. But since everything works fine, it just sits in my drawer ready for use.

    • +1

      Cool. Thanks.

      For phones and tablets, there's also free app's like Ampere on Android that can display charging current

      https://play.google.com/store/apps/details?id=com.gombosdev.…

      • Apps can only show the net current drawn by the device; which means you will never know the precise charging current until you figure out how much the device uses at the same time. To make it worse, the app doesn't work when your screen is off. Those apps are no better than the estimated charging time provided by your phone.

        • Makes sense. Thanks. I'm genuinely curious under what circumstances the average-joe would need such detailed accuracy and would the extra cost even be worth it?

          For example, in my case, I only downloaded the app once because my phone seemed to be taking a lot longer to charge. The app confirmed a very low current. (Turns out my charger was fine, but the USB cable was dodgy.) Given the cost to fully charge a phone every day is estimated to be less than 50 cents a year, I'd be hard-pressed to justify spending even the 99 cents for the listed device when this app provided a good enough solution.

        • @surethang: A device like this is to test the performance of a charging system. Eg. Connections between adapter, cables and end device. Those apps aren't just inaccurate but pretty much useless in most scenarios - they are off by up to 1000mah. In some cases, they show that the device is discharging when plugged in. And most importantly, this little gadget is $1, it's a no brainer.

    • Be aware this can actually effect (reduce) how much current the device pulls due to its added resistance

      • +4

        Of course, by a fraction of a volt. But a device is not a simple resistance either. It regulates its charging current.

        PS: * affect.

        • +1

          You'd be surprised, intelligent devices like phones often try and estimate the amount of current a source can provide by how its voltage dips as more current is drawn (that and using the data pins). Because these are cheap chinese devices made to a price they have a fairly high resistance hence a greater voltage drop which the charging device can register, which causes it to draw less current. Source: Ive got like 4 of these

        • @joungs: 200mV according to specs above. USB power supply variation is of that order too. I've got one that puts out 5.2V. For checking things are more or less OK, it's fine. One doesn't leave this sort of thing in circuit. Watching the voltage and current gets old quickly.

        • @greenpossum: Connect two of these in series and you can see just how big the voltage drop is. Yeah im not talking about leaving them in circuit but it doesnt give an accurate representation of how much current your device will use when plugged directly into the source.

        • @joungs: One doesn't always need that kind of accuracy. This meter is just to get a rough idea of what your supply is putting out and how much current your device is drawing. I would actually say that most people don't need this gizmo. If one sticks to the recommended PSU capacities for your device, it either works or not, the charging symbol appears, the LED lights, or not. But I like having something in between that extreme and the other extreme of making accurate measurements which would require me to construct an adaptor cable to insert the meter in series.

        • +1

          @greenpossum:
          Ive had devices drawn 10 watts when plugged directly into the source but only 4 or 5 when used through one of these so can be a big difference!

        • @joungs: That is caused by the connections between the extra plugs. You will get the same problem when using a bunch of converters.

        • @joungs: Did you measure the current with an accurate meter with a breakout cable with and without this gizmo? Maybe your device is sensitive to power voltage or cabling so this device isn't for you. I haven't got devices that fussy.

        • +1

          @greenpossum: on the tinkering side of usage I find this useful for keeping "smart" power banks active when testing my circuits. Often my circuit draws so little current that the power bank will automatically turn off because the load is too small. This device draws enough to keep the power bank on.

        • @greenpossum:
          That may be so but people should be aware that this is effecting the current their devices draw, sometimes quite significantly. And yes was measured accurately on the output side.

  • +4

    Alternatively if you want to know if a port is powerful enough to charge your device, simply plug in your device.

    • -5

      Alternatively alternatively many households will have a volt/current/multi-meter available for use. You can test the USB port by measuring it's outer pins, one being 5V and the other being ground (0V).

      • +1

        It's too hard to measure the current on a USB port with a multimeter, you'd have to sacrifice a USB extension cable, which probably costs the same (or more) than this gizmo.

        • I just tested and confirmed that the voltage output of my PCs front USB ports is 5V, which they are. Took me less than 5 seconds with a voltmeter so it wasn't hard. If I had a current meter I would have done it this way too.

          Not sure if people are down voting me because they think it's hard with a multimeter, because they haven't invested in one ($10 at Jaycar) or for some other reason. I'd assume people think it's an unsafe risk if you don't know what you are doing and measuring in this way.

          I'm also not sure why a USB extension cable is necessary. The USB port pins are already accessible without a USB extension cable.

          My point is that you can use a multimeter for this purpose as well.

        • @Ragoon: Please explain exactly how you'd measure the current being drawn by your phone with a multimeter and no scrap cable?

          My method:

          1. strip some middle section of USB extension cable
          2. cut either the red or black wire (only one, not both!), strip off a bit
          3. connect multimeter (in current mode), one lead to each of the ends of the cut you just made
          4. plug in USB cable to phone and charger, read the number

          Note that current must be measured in-line, you can't just connect across the +ve and -ve supply terminals…

          You could use a clamp style current sensor, but you'd still need the cable to split apart so you can put one (and only one) of the power wires through the clamp thing.

          People are downvoting because you missed the joke and your method cannot measure current. (It's also awkward to measure voltage from a USB port with a multimeter, the probes usually want to short against the outer shell.)

        • @abb:

          I doubt you have fully read my previous reply. I'm 100% sure you haven't tried measuring with a multimeter yourself because you are just too doubtful of this method and therefore it is unknown to you.

          What I wrote:
          "If I had a current meter I would have done it this way too."
          "My point is that you can use a multimeter for this purpose as well."

          As mentioned several times now, and hopefully you are reading this, if I had a current meter or my meter instrument had a current scale reading I would have tried measuring the current.
          FYI most multimeters will have a current setting that can be used to measure the USB port current output. This current output value is therefore the same current value your phone will be receiving but not necessarily making use of due to resistors and capacitors.

          If you are too stubborn to not at least practically try measuring with a multimeter than you are obviously missing out. However, I do agree that there is a chance for a shortage but it will not happen if you do it properly!

        • @Ragoon: I'm an electrical engineer. I work at a very well respected organization in this capacity, and I have $30 000 worth of electronics test gear on my desk right now.

          I know how to measure current.

          FYI most multimeters will have a current setting that can be used to measure the USB port current output. This current output value is therefore the same current value your phone will be receiving but not necessarily making use of due to resistors and capacitors.

          If you are so confident, please try this and tell me what reading you get.

          Edit: For clarity: you are wrong.

        • @abb:

          nope. Just doing it the right way.

        • @Ragoon: Still waiting for those measurements, champ

        • -2

          @abb:

          You are obviously dumb. Read my reply over and over again until you understand.
          Won't tell you again because you are just triggered over the situation.

    • +1

      How do I do that with an app though?

  • +1

    I've got a similar one, different shape/colour but probably the same basic control circuitry. It's pretty much only useful for really broad basic indications as the number shown (mainly the current reading) is pretty inaccurate, everytime I've compared it to a multimeter anyway. But I have found it useful for that as with my hobby projects I can see if something is working normally or not (e.g. if it says it's pulling 500mA+ but I know it's not meant to be anywhere near that then I know to turn it off quick and check my circuit)

    … sadly I paid more … much more for mine :(

    • +1

      I have the same color one. I want to add that I found mine only registers larger currents, small currents gave nothing unfortunately.

      Maybe look for a better model if you really need one people.

  • +1

    Thanks OP - got a Thor hammer toy to add to my trinket collection.

  • +1

    Another gearbest treat in the mail…. a few weeks later of course..

    • Few meaning 4 then

  • Thanks, was wanting to get one of these usb trinkets, there is a much nicer black one you can find on aliexpress, but this one will do for my use. Cheers!

  • bought one of these years ago - it didn't work.

  • +1

    So the voltage detector wont support Quickcharge @ 9v/12v?

    • Correct, nor most USB C power delivery stuff like modern phone chargers. Good for measuring current draw in USB devices for electrics hobbiests though.

      • Crap for measuring current draw. Good for measuring if there's "any" current at all though.

    • There are better ones on Aliexpress that do support a greater voltage range, but at a greater price than this of course. I paid a bit under $5 for mine a while ago.

    • +1

      Yes it probably does. I bought one from banggood, different design but it also stated to work with 5v only but seems to work fine on couple of qc2.0 devices.

  • +2

    Thanks OP, got the hammer to add to my collection of metal folding toys that I'll never build.

  • +2

    Here's the most detailed test I could find on youtube, where someone verifies the readings with a quality multimeter: https://www.youtube.com/watch?v=QpQhlwkhCNY

    It turns out that it is pretty accurate. Gonna order.

    • Mine's not accurate at all. Are you sure it's the same meter?

      Edit: looks the same, even in this video it shows the issue I had… Note the 0.3A draw on a bloody phone lol. Phones usually pull 1A+. Seems it just doesn't want to pull full load through it (I assumed it was just a faulty reading and was pulling full rate), but either way it won't give you any kind of accurate reading to what you'd get without a meter in between.

    • Purchased one about 3 years ago.

      Tested its accuracy with a Flute and found the voltage and current draw to be extremely accurate from memory. Had to take apart an old cable though to do the measurements.

      BTW mine appears to have identical color and markings from the photos on GB product page.

      • Where'd you get your USB-powered flute from? ;)

  • $0.99 for me

  • Don't waste your $1 on the USB meter, very inaccurate.

      • Just watched this, he only tests with small currents (ie 0.3A), mine was usually weird at higher currents (1A, 1.5A, 2A and 2.3A on different deviced). It would simply show amounts around 0.5-1A (or slightly below at times).
        I'm yet to try the testers in series to see if devices are simply drawing less through this device for whatever reason or if they're drawing full amount and it's not displaying it, but either way it'll give you an inaccurate reading of what your devices draw on a direct connection (without a meter in between).

        Edit: maybe his in video is worse than mine… or maybe with the longer cord he uses. Note the phone only draws 0.3A, this is similar to the issue I saw. On other metres the same device(s) pull easily 1A+.

        • +2

          So how do you know what's the current drawn without a meter in between? Unless you have one of those clamp on current sensors?

          Maybe his device was only drawing 0.3A because it was almost charged?

        • @greenpossum:

          1. Logic (ie a 20,000mAh battery charging at x rate with x efficiency should take x time)

          2. Using multiple other meters (most get the full rate, some 10-20% below (the cheaper ones usually)… I'm assuming it may actually be due to a voltage drop inside the cheaper wiring that causes lower rates maybe?)

          3. Comparing to what the device is rated to pull. Not always accurate, but with most of the higher quality power banks all the other meters are close or (as mentioned) some will be a little lower, but still close enough to give you an idea.

          Isn't 100% solid proof, but overall it's safe to say the numbers (at least in my case) stack against it.

          You are correct though, I haven't used any expensive equipment to confirm this…

          As an example, it said my 20,000mAh power bank was drawing 0.6A. It usually charges overnight. Quick math tells us that doesn't add up lol. Not accounting for losses, that's around 24Wh overnight - far from ~70Wh+. Now you could also argue the power bank is wrong and isn't actually 70Wh etc etc, but it charges my phone roughly the right amount of times and I'd say it's accurate. Others have done more in depth tests on this.

          Over all, the video literally shows a similar problem to what I seen - a very low power draw to normal circumstances. A phone drawing only 0.3A is very unusual.

          Edit:
          https://www.banggood.com/MantisTek-White-Tail-USB-Doctor-Vol… one I mainly use now. Mostly because it has the microUSB input to test the voltage loss over cables (ie plug it directly in via USB, then unplug and plug in via microUSB cable and note voltage difference).

        • +1

          @dyl: There is too much variation in the various calculations you use. Chargers introduce some efficiency drops. Residual charge in the batteries affects the time to full charge. Charging current may not be constant throughout the period, and probably drops off towards the end. Quoted capacities may be inflated. You really have to compare with a quality meter to say.

          You say a phone drawing less than 0.3A is unusual. That's a sweeping generalisation. I just measured my phone and it's about 0.25A. That's probably because it's fully charged so that's the quiescent current. If I turned if off it would be less. And I'm sure a feature phone will charge with less. But it just shows that it can vary a lot.

          However this device is not meant to give you that kind of accuracy. The two things of interest would be, is the device loading down the USB power supply? If the voltage is significantly below 5V, then yes. If the current reasonable? If too little then maybe the device isn't charging. If too much, then perhaps that RPi is a tad too current hungry for the power supply. What do you expect for under a buck? And without having to rig up a current meter in series with the USB cables, beyond most people without some connectors, wires, and soldering iron.

        • +1

          @greenpossum:
          If it gave you at least an idea of things it'd be fine, but showing a phone drawing 0.3A isn't correct. In my case it showed more around 0.6A on phones that draw around 1.5A on other meters. Either way, it doesn't even give an idea of things.

          I thought I explained this well enough above - 0.3A * 5v * 8hours = 12Wh.
          My phone battery is ~3400mAh @ 3.7V. for clarify, we'll say 12Wh too (it's just over). With this math, assuming 100% efficiency we would see only one phone charge out of the 20000mAh power bank if it was charging that slow over night. I see more like 4-5. You could dive right into tinfoil hat territory and say maybe my phone(s) (OnePlus 5 and Xiaomi Note Pro before that) lie about their capacity, but I won't go there.

        • @dyl: Maybe like a guy above you have a device that's sensitive to power voltage and cabling, and this one doesn't support your device's charging protocol. AFAICT the one you posted works on the same principle, measuring the voltage drop across a known resistance, but may handle the charging protocol better. In such a case, an accurate meter and breakout cable would also not handle this. It would be interesting if you could put this to the test.

        • @greenpossum:

          "Yeah it'll give you an inaccurate reading when another will give an accurate reading, but that's just because of your devices and not the meter".

          I perfectly understand what you're saying but I don't see how the meter is useful when the fact still remains that it won't show the same power draw as you'd see through another meter. If the meter is effecting the current your phone can pull, then it's faulty and won't show an accurate reading of what your phone can pull.

        • @dyl: It means that this meter isn't for you then and you need a better meter. It's fine for my purposes.

    • good enough to get a rough idea, if my anker cable charges my phone at 1.4 amps and the Kmart one charges at 340mha the Kmart one is shit.

      • What about when your Anker cable is saying 0.6A on this and a cheap Chinese one 0.4A? Hard to draw any kind of solid conclusion.

        Can maybe conclude the Anker cable is better, but I think even a monkey can conclude a cable from a reputable brand is better than a cheap Chinese Kmart one… You could almost just measure the thickness of the entire cable and conclude which is likely to be better without any testing equipment lol

        • I also have a switchable 1 or 2 amp load, you can see the voltage drop on a shitty charger. is it great, no but it's good enough to get an idea. a lot of cables have super thick outsides and really thing conductors inside

        • @fleabag:

          Guess with a fixed load it'll work, the main problem is with phones that try to negotiate the current.

  • +2

    bitterly disappointed that it is not a Peter Gabriel 3D puzzle

  • Loving these little metal puzzles. Sure beats paying >$10 for them here.

  • Sad because it doesn't measure higher voltage - QC 2 QC 3 is more than 9V

  • +1

    Last time I bought one of these it died in no time. Worked for about a month. Wouldn't recommend this low quality gimmick to anyone. You're better off forking out more cash for something that isn't a scam if you want to actually use this for more than just a fleeting moment's interest.

    • I only want to use it like once, for about 2 minutes.

    • Earth to Supersabrosa - it's $1, think i'll take the chance

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