Yes — with a couple of caveats, of course.
If it’s not made specifically for your particular computer, getting the right power supply is important, and involves matching voltage, amperage, and polarity.
Each have different constraints.
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Let’s start with the simplest: voltage.
The voltage output by your charger or power supply must match what is required by your computer or device as closely as possible. In your case, you’ve got this covered: the old charger supplied 19 volts and your replacement is also 19 volts.
It’s important to get the right voltage. Some devices are quite tolerant of voltage variations and will work just fine. Others, not so much. The device may work with voltages that are close, but often at the cost of shortening its lifespan.
If the voltage is significantly off, it can damage your device.
Because there’s no easy way to know which category your device falls into, you should just make sure to get the right voltage from the start.
Many people are confused by amperage ratings and what they mean when it comes to power supplies and replacements.
The amperage rating is the maximum amount of power it can supply.
One way to look at it is as if amperage were “taken” (often referred to as “drawn”, as in pulling) by the device being powered. That device will only draw as much amperage as it needs to perform whatever it’s doing. Your computer will use more power, in the form of higher amperage draw, when it’s working hard than when it’s not. (Voltage remains the same regardless.)
Thus, as long as you replace your power supply with one capable of providing as much or more amps than the previous supply, you’ll be fine.
If for some reason your replacement power supply has a lower-than-required maximum amperage rating, you may end up with a burnt out or overheating power supply, and the device itself may not function.
Input voltage — the power you get from the wall socket into which you plug these devices — is really interesting.
These days, for most power supplies, almost anything works.
If you look closely at many power supplies, you’ll see they’re rated to be plugged in to anything from around 100 volts to 250 volts as input. That they can do that — take just about any input and create a fixed, stable output — amazes the electrical engineer in me.
It also means that most can work worldwide with nothing more than an adapter to account for the physical plug differences – no transformer needed.
Check your power supplies before you travel, of course, but it’s very, very convenient.
This final item catches many people by surprise, especially when replacing simple or small power supplies with generic equivalents.
Most power supplies provide DC (direct current) power via two wires, labeled positive and negative. Polarity refers to which wire is which.
Just because the physical plug into your device matches doesn’t mean that the positive and negative connections are hooked up the right way. In fact, there’s often no real standard.
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. Failure to get it right at best simply doesn’t work, and at worst damages the device. Look carefully for indicators on both the power supply and the device to which you’re connecting it.
The good news here is that there are some standards where the polarity is always the same and always correct. For example, USB is a standard that more and more devices are using to supply power. In that same vein, if you’re replacing a power supply that uses a custom connector used only by one manufacturer, then you won’t have to worry about polarity either.
In short, when replacing an external power supply or charger:
- Make sure the voltage matches.
- Make sure the new power supply is rated to provide the same amperage or more.
- Make sure the connectors match, both in physical form and in polarity.