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Understanding Voltage and Current. An analogy with water in pipes is often helpful in understanding the basics of electricity. Voltage is like water pressure. It is a force. If the force is too strong your pipes will burst. Too low and your shower may not work at all. Current is like flow-rate. Litres per second or how fast your bath fills. It depends on ...


5

You don't need to reduce anything. The headset is designed with a particular internal battery that has particular charging specifications, and its circuitry will not take more than whatever it is designed for (450mA in your case), no matter how capable the 5V source is, 1A or 10A or 30A. FYI, USB cables do not "demand" anything. At most, if they have Type-C ...


4

There should be no problem with keeping it plugged into the socket. With modern adapters there is no need to worry about the order you plug things in (unless you are superstitious). The only problem that I could think of would be the adapter getting hot - you forgetting about it being plugged in and maybe placing things on top of the supply that could ...


2

"Just isolate the ground on the adapter" Followed as above. Only difference I did was taped the Earth terminal with masking tape & "Voila" It worked.


2

Normally when you use adapter, that has lower power output than the device you supply power to requires, adapter will simply heat up and die. In case of laptops, where battery has some charging logic, it will probably not charge or take very long time to charge, depends on how you use this laptop. I don't know if the adapter will explode in this case though. ...


2

Looks like the statement what the adapter can handle is 8 times the device "Foo" (some camera), and the device "Foo" has an input rating of 12V 5A possibly. Looking at the data sheets, we have: The input rating of 12V 5A that is a conservative estimate (maybe very conservative) and a maximum value while the adapter's output rating of 12V 7A is a ...


2

You absolutely, positively need to make sure the output voltage of any new adapter is identical to your old adapter. You'll cause damage to the computer if you plug in an adapter with higher voltage, and one with lower voltage will be inadequate. The output amperage doesn't matter as much. A little variance in the output amperage of the new adapter should ...


2

It could potentially incur damage if there's a power surge (e.g., lightning or power transmission event). Why not just use a surge protector (or even a regular power strip) with an on/off switch? This is a pretty common configuration, and lets you turn off the power to multiple devices (monitor, USB hub, etc) with the flick of a single switch.


2

19.5 volts should work fine and will not destroy your laptop (19 and 19.5 volts are close enough to each other). 16 volts will work but charge the battery more slowly. Use the matched 19 volts. Make sure the polarity of the universal charger matches. The back of the laptop or its documentation will tell you that. The charger may say it is approved for your ...


1

First option, search for "devicename devicemodel# power adapter" on ebay. You might find actual genuine branded used adapters for that exact device. You will also probably find 3rd party adapters for the device being sold by sellers in China. The 3rd party adapters will probably work OK but may not be as good quality. Second option. You can buy generic ...


1

It may be that the laptop's power manager is deciding that charging past 87% will be harmful to the battery's life. It also may be that the new battery is not calibrated yet and so it really is 100% charged even though it's only displaying 87%. You aren't reporting any actual problem (such as poor battery life) so your issues seem to be purely cosmetic. Use ...


1

Input doesn't matter regarding laptop chargers. As long as the output matches the output of your charger, the replacement will safely work. The input on the charger is recording what goes into the charger, but we want the output (what the charger sends to the laptop) to be the same. Hope this helps!


1

We got about 10 of these same adapters around our office. They are used daily with T440 and X240 without issue. The extra current is perfectly fine. The circuitry inside the laptop determines how much current is drawn. And it will only draw as much as it needs. It only means that the adapters maximum capacity will not be fully utilized. The voltage ...


1

Sometimes the ACPI driver is messed up. I have experienced this problem a few times on my trusty Dell Latitude E6410. This procedure gets things going Disconnect the AC from the laptop Shutdown the computer Remove battery Re-connect the AC Startup the computer Go to Control Panel and open Device Manager Expand the Batteries category and right-click all of ...


1

An operating system wouldn't have anything to do with your system being charged by your adapter. Based off of your statement that other adapters charge your system fine, and that particular 90w adapter (which I'm also assuming is the one that came with your laptop) is not, and including that you upgraded your OS from XP (translation: old equipment), I'd ...


1

The safest option is to get exactly what your computer came with, but I guess you can get something close enough. Usually power supplies, original or third party tend to be for specific makes, and the designs tend to be consistent externally. I used to switch my old IBM era power supplies between thinkpads, and do the same with the newer lenovo power ...


1

Without getting an electrical engineer to open up the box and have a look we can only speculate. There are 2 or 3 likely reasons why this is working - The box will work at 5 volts (or less), and has some voltage regulation circuitry to carry out this function. This is quite common, and "voltage regulators on a chip" are cheap and ubiquitous. It is ...


1

It's a ground loop problem with Synaptics touchpad (Dell Inspiron 14 in my case), maybe related to a bad power supply. I'll edit this reply if other PSU fix the problem. As some other people say, a fast workaround is to touch notebook ground: Make a couple of loops around power plug with a clip and touch it while using the touchpad. You can also use any USB ...


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