AC to DC 12V 1.5A Power Adapter Supply, Plug UK 5.5mm x 2.1mm

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Oh Leo, you’re a great IT guy but not so hot at getting electronics across to beginners. I could agree with your definition of Voltage – the ‘push’ on the electrons that tries to make them move and make a current, but not your definition of Current. The load / laptop / whatever does NOT pull – it lets the current through; faster if the resistance is low, slower if it’s high. Current is how fast the electrons (that carry the charge) are moving. If you look closely at the small print on many power supplies, you’ll see they’re rated for anything from 100 to 250 volts. This means most can work worldwide with nothing more than an adapter to account for the physical plug differences — no voltage transformer needed.

12V 1.5A UL Listed 18W AC DC Switching Power Supply Chanzon 12V 1.5A UL Listed 18W AC DC Switching Power Supply

I am an electronics guy and am with Leo on this one. Andrew’s comments are more about the internals of a device being run but the question was about the current rating of a charger. The amperage rating of a charger or power supply is the maximum it can supply. A device being charged will only take as much amperage as it requires. If your device needs 0.5 amps to charge, and your charger is rated at 1.0 amps, only 0.5 amps will be used. Particularly when it comes to popular circular power connectors, make sure the expectations match. If the device expects the center connector to be positive and the outer ring to be negative, your power supply’s connector must match. There’s no getting around this.

What is the difference between the types of power supplies?

Thus, as long as you replace your power supply with one capable of providing as much or more amps than the previous, you’ll be fine. In other words, there is nothing wrong with having a charger capable of providing more amps than needed. Polarity The amperage provided by your charger must match or exceed what the device being charged requires. Amperage Provided Versus Amperage Required Power Supply or Charger Amperage Rating

12 Volt 1.5 Amp Worldwide Power Supply (US/EU/UK/AU) Nebra 12 Volt 1.5 Amp Worldwide Power Supply (US/EU/UK/AU)

Leo, I agree with your analogy re power supplies. However, your statement that voltage is constant is not correct. If you load up a power supply, you will have losses in the wire that connects the supply (wall wart) to the device. Engineers like to refer to this as IFor Mr. Keir. I prefer to think of current as volumn and voltage as pressure. An example being a water pipe with a pressure/voltage of 10psi and a diameter(volumn)/current of 1 inch allows so much water through. Increase the volumn/current to 2 inches and it lets 4 times as much volumn through. aka available wattage. ( I think I got that right) Its been a long time…. It’s very important to get the right voltage. Some devices are tolerant of variations and work just fine. Others, unfortunately, are not tolerant at all. Depending on how different the supplied voltage is from what’s required, the device may simply fail, it may work “kind of”, or it may appear to work at the cost of a much shorter lifespan. Yes. Because a) the voltage matches, and b) the amperage provided is greater than that needed, you can use a 5v-2A charger with a 5V-1A device. Is 500ma the same as 0.5 A? Just be careful with some laptops. I know that with my Dell laptops, if the chip in the charger goes bad (the chip that tells the Dell laptop that this charger is the correct charger for the computer), it will no longer charge the battery, and the laptop will draw less power (or amps – but Amps times Volts gives you Watts – or power) – thus slower laptop. Their reasoning, is so you don’t plug a charger in that isn’t rated for your laptop and damage it, but it forces you to only buy the correct Dell chargers, and when that chip goes, even if the charger is working – you no longer can charge, and you have a slower system (even my USB ports wouldn’t produce the correct power output when the Dell isn’t able to read the charger’s chip.)

AC / DC Enclosed Power Supplies | Farnell UK 1.5kW AC / DC Enclosed Power Supplies | Farnell UK

Your water analogy is incomplete: voltage is the water pressure, and amperage is the SIZE of the hose. A small hose under a lot of pressure will get you wet; a huge hose, even under low pressure, can wash you away. But none of that has to do with the volts pushed to and amps drawn from a computer, really. When replacing a charger, this is easy to determine: it’ll be listed somewhere on the old charger. In your case, the old charger supplied 19 volts, so your replacement must also be 19 volts. If it’s not made specifically for your particular computer, getting the right power supply is important and involves matching voltage, amperage, and polarity.The problem, of course, is the reverse: if your device needs 1.0 amps, but your charger is rated at only 0.5 amps, then any of several problems could result: Electrically speaking, higher voltage can cause more amps to “flow”. This is one reason why getting the voltage correct on a power supply is so critical, because it can, in a sense, “push” too much electricity through a device and cause it to overheat or be damaged. Can too many amps damage a device? The input line voltage (wall or “mains” power) must be supported but is unrelated to compatibility with the device being charged or powered. And here’s the problem: there’s no way to say what’s enough or too much. It varies from device to device. Some may tolerate a wide range of input voltages, while others are extremely sensitive to even the smallest error.