If the device says something like “DC-12V-IN”, will any 12V AC adapter with the correct connector work?
And why don’t they mark the adapter somehow so it’s obvious which device it goes with?
In: Technology
The correct voltage is one part. You’ll also want to see how many amps the device will draw and make sure the adapter can deliver at least that number of amps.
1 voltage matches exactly
2 device current (amps) is less than or equal to supply rated amps
3 the plug fits
If those are all good, it’s good to go.
Good answers above. To answer your last question: because the device manufacturer doesn’t make the power adapter a lot of the time. They are just commodity items purchased from a company that produces nothing but power adapters by the boat load. Then they sell these to “gadget” manufacturers. Customizing the case, even to put a logo on it costs money, and would be totally pointless from the manufacturers point of view.
There are a few different factors that need to be considered:
* AC vs DC
* Voltage. The power source needs to provide a voltage within this range. For DC, its likely a low single number.
* Wattage or amperage. The power source needs to be able to support *at least* this amount. Wattage and amperage are *not* the same: `watts = amps * volts`.
* If DC, there should be an indictor for polarity. This is typically shown as a half circle with a dot inside linked to a + and – symbol. Some devices don’t care about polarity, but many will.
* If AC, there should be a frequency listed, or a range of frequencies. In the US, this will typically be 60 or a range that includes 60.
If the input matches *all* of those, you can use it if the plug fits.
As such, the information you provided is not enough. You know you need a 12V DC power supply, but you fail to specify the required polarity and the required wattage.
Many devices do use fairly unique connector types, however that has the drawback that it is much harder to replace the charger if it breaks or gets lost.
That problem is part of the reason USB has taken over a lot of DC charging systems. Its a single standard specification that can support a *huge* range of DC inputs by design, while also being able to be used for communication. The drawback is that USB requires a lot more complexity for the device, cable, and charger – you need a fairly complex computer chip in each, even if only using it for power.
> And why don’t they mark the adapter somehow so it’s obvious which device it goes with?
They do. The adaptor has the Volts and amps it supplies printed on it just like the device has its requirements printed on it.
As long as the numbers match up, it can generally be made to work with the right connector adaptors.
Power supplies are not designed for an exact device and only. They are sold with exact devices, but they are as good as any if parameters are the same (might also be more powerful than the genuine one).
You DO have marking on devices and power supplies what kinda input/output the require.
Power supplies has output parameters saying what kinda electricity it provides:
– polarity, which is usually a small icon showing where + and – are on the plug, either + is on the outside or on the inside of the plug. The image below shows both polarities:
[https://i.sstatic.net/zsp7C.png](https://i.sstatic.net/zsp7C.png)
– voltage, which has to parameters: value and type e.g. 12VDC means 12V of DC voltage, can also be 12VAC, which means 12V of AC voltage, but you won’t see it much, our whole customer electronics world runs on DC, but just beware that AC/AC adapters are also a thing, just not for what we typically need to power.
– current, which is stated just as value e.g. 10A or can be smaller units e.g. 1mA (milli, which is 1/1000 of 1 A)
You will see the same params on your device you wanna power, but it’s gonna be marked as input params and it means what kinda electricity must be plugged into the power port.
Rules are as below:
– polarity MUST be the same
– voltage MUST be the same
– current MUST be AT LEAST the minimum your device requires, but can be higher
That’s it.
One more thing, you will sometimes see AC and DC labeled as symbols, that is another way to figure out if it’s AC or DC:
[https://electricalinstallationservices.co.uk/wp-content/uploads/2019/04/AC-vs-DC-scaled-e1674633632251.jpeg](https://electricalinstallationservices.co.uk/wp-content/uploads/2019/04/AC-vs-DC-scaled-e1674633632251.jpeg)
I usually get a strip of masking tape, loop it around the cable just below the plug part and write on it what it’s for to save that hassle.
You’ll tell yourself you’ll remember what is what but you won’t. Especially when you have several devices and their respective power adapters stored in the same area.
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