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96

Most power conversion devices contains coils, such as transformers or inductors. These components use electromagnetism to convert AC mains power to low-voltage DC power. The varying magnetic fields generated by these components can cause them to physically vibrate at high frequency, resulting in a high-pitched noise. Most modern AC adapters are switched-...


17

A "switching" power supply (like virtually all modern computer power supplies) works by "rectifying" the incoming 120V 60Hz (in the US) AC power into DC (at around 170 volts), "filtering" with capacitors, then using a semiconductor circuit to "chop" the DC voltage around 1000 times a second to turn it back into crude AC. (What's referred to as a "square ...


14

You have a mostly-dead battery. Not running without the battery is an unfortunate but common design choice that shackles you to spending money on a battery that may cost a significant portion of the current value of the computer when the battery becomes fully dead. For now, the 30 seconds of life it has is evidently enough to get started, so be happy about ...


11

Type-C original specifications (and Power Delivery specifications over Type-C connector, if any) are designed precisely for the sake of compatibility and inter-operability. Since both Type-C devices come from reputable manufacturers, I would expect that they are compliant to all related specifications, and no harm will be done to any of your devices. The ...


9

The spark you see is completely normal. The reason has nothing to do with 'in rush' current or capacitors. It has to do with inductance. Any wire loop (any conductor has small inductance), such as a transformer, has an inductance. The transformer has a magnetic field (or lack of one) and when you plug-in or unplug the cord, current flows/stops and the ...


8

The transformers are created in part by gluing plates of metal together. The AC fields causes back and forth forces in the metal plates. As the transformer ages the plates begin to separate and allows for movement on the plates which vibrate causing the humming sound you hear.


7

tl;dr: Most likely, this will simply not work. Not worth trying. Firstly, it's quite clear that it won't meet the 45 W the laptop expects. With traditional chargers (those that are a 'dumb' DC SMPS) what will likely happen is as the laptop requests more current, the voltage will start sagging until it reaches a cutoff and the laptop stops charging. Unlike ...


6

Is there anything I can do to suppress it? As they've already told you, glue, because glue adds damping to the vibrating coil, then the coil's stationary response gets smaller as well as the noise produced glue adds constraints to the coil, then the coil's (mechanical) fundamental frequency increases above your hearing capability. Another solution that ...


5

First, you need to check what your device REQUIRES. If the device requires a steady 3.42 amps and you're providing only 2.4 amps max, then the device (laptop?) will attempt to pull more current than the PSU was equipped for. Which could result in PSU failure, laptop failure or even worse, a fire. Now, assuming the device ONLY needs to pull 19V and 2 amps, ...


5

The laptop would only use the wattage it needs. The chargers most likely have the same connector to the laptop and the manufacturers are offering higher wattage to make their chargers more appealing to a larger market of Acer laptop users. Without knowing anything about these laptops — and using basic deductive reasoning — let’s just look at which laptop ...


5

USB C is a dense pinout connector and Power Delivery requires more than just the "standard" USB 2.0 pins of Data+, Data-, 5V and GND. From EE: How does a USB C port provide the power to charge laptops? you can see that the CC1/CC2 pins beside the D+/D- pins are used to communicate for USB PD. This is the main reason why Power Delivery does not ...


4

When you wrap the cable up, you can clip that to another part of the cable to keep it neat.


4

My laptop makes an annoying beep sound whenever I plug or unplug the charger. Windows 8.1/Windows 10: Disable the System Speaker device: Open "Device Manager". Scroll down to "System Devices". Click on "+" Right click on "System Speaker". Select "Disable" Restart your computer. Beep should be permanently disabled. Windows 7: Disable the Beep device:...


4

It definitely sounds like their MacBook is not properly grounded. Take it to an Apple store for service.


4

Yes, as long as the voltage is the same and amperage is more than required, the laptop charger will work (assuming the plugs fit)


4

Assuming they're both genuine Lenovo chargers with the same connector, the answer is most likely yes. Case in point: my HP ENVY x360 13 shipped with a 45W adapter. It'll charge on a separately-purchased HP 65W adapter, with the higher output allowing it to charge faster than the 45W adapter when the laptop is in use. It'll also charge from any USB Power ...


4

That kind of splitting would be dangerous and potentially damage devices. If you need a splitter then buy an active hub. I cannot find any that advertise multiple PD outputs (only pass through for a laptop) and this would likely need a lot of expensive power conversion to handle, see the rest of my answer below. You would be best off getting a PD power brick ...


3

As per the details provided in comment by OP: Original Charger Input 100-240V ~1.6A 50-60Hz Output 18.5V 3.5A 65 W Pin Size 7.4 x 5.0mm Replacement Charger Input 100-240V ~1.5A 50-60Hz Output 18.5V 3.5A 65W Pin Size 7.4 x 5.0mm They can be safely used as they both have the same output voltage and output current and are rated for 65 watts. The stated ...


3

To be absolutely safe: No, you shouldn't use chargers with different voltages at all and if you do, you will most likely void the warranty of either the laptop, the charger, or both. That also goes for the safety guidelines so if anything exploded in your face, YOU would be responsible. (Except maybe the charger manufacturer could be if they officially ...


3

Buy a different charger. The charger you bought only has current of 4.5a, apparently you need 6.15a or somewhere closer to that. FWIW, the charger you buy could be anything over 6.15a, just not under. The voltage should match exactly, although 19 might work. That UNIVERSAL unit isn't so universal.


3

It sounds like there might be a fault with the onboard electronics or power adapter and the battery is not charging. In the case of the adapter it might not be providing enough power to charge the battery. An inexpensive multimeter from your local electronics store would be able to verify the output of the charger. Laptop adapters are pricey so it is ...


3

I had a similar issue to this with my laptop charger twice over the years and I found that replacing the charger cord fixed the issue. Upon inspection of the tip of the cord the plastic shroud was very weak and in my case a tiny bit was missing which was exposing the wire. Only when applying pressure in a very specific spot could I get the laptop to charge. ...


3

The official Samsung charger has a rated output of 2 Amps, which is quite a lot, hence its size. On the other hand, standard USB has a 500 mA (0.5 Amps) maximum current rating, and an ordinary generic USB charger is likely to top out around there (or much less, if it's cheaply made). The reason for the high current output of the official charger is the ...


3

Converting 5 Volts to 18 (or 24, or...) Volts is quite possible, but to pull 65 watts (much less 85, much less adding conversion losses) from USB's 5 volts would require getting 13 Amperes (current) from the USB port, and THAT you won't find anytime soon, if ever. Some of the high-current special jobs go to 2 Amps (10Watts @ 5Volts), stock is 500 mA (2.5 W) ...


3

You are correct in the last part - a USB port will never output enough power to get a laptop going. Most laptops are around 18 volts, and the maximum a USB port will put out is 5 volts. An average laptop is around 18 volts (65 watts or so) and upwards from there. (Mine is 85 actually). tl;dr version: No.


3

Whether a laptop power-adapter will spark or not when plugged in depends on a variety of factors. Anatomy of a Power Adapter The adapter “brick” acts as a both a surge protector and a minor UPS (uninterruptible power supply). In addition to filtering and condition the incoming power to even out minor surges and dips in the power, it also has a large ...


3

A similar question, at one point marked as a duplicate, focuses on a voltage difference between the original charger and a replacement. The answers on that one do a good job of addressing that issue. Here you're talking about 1/3 lower current rating, which is a different issue. Short Answer: A charger with that much lower a current rating is unlikely to ...


3

The brick which are calling a "charger" is not actually a charger. It's an AC to DC converter. Monitor and the laptop each have their own built-in charge controllers (and do those special things that keep Lithium batteries out of trouble). This AC to DC converter's purpose is to supply the right voltage and sufficient current (or power, since P=IV). If ...


3

This is a Serbian "conformity mark", mostly equivalent to the European "CE" sign (that is, both have the same requirements). http://www.bsccentar.rs/index.php?page=tria_eng http://www.ratel.rs/regulations/rtte/about_rtte.582.html


3

It's pretty much standard with 2 pin chargers and a metal case. It's not dangerous, just electrical "noise". The intensity may vary slightly if you plug it into a different wall socket, or go through the other wall sockets and disconnect devices that likely add noise (such as chargers, transformers, both even if turned off). Depending on the circuit the ...


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