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DC adapters: why so few amps?

up vote 14 down vote favorite

If I have a device that draws 5 amps at 12 volts, I can use any 12 volt DC adapter that can provide at least 5 amps.

Why don't all DC adapters have the capacity to provide loads of amps!? If all DC adapters provided e.g. 1000 amps, we would only need to care about the voltage value.

Do too many amps make DC adapters bulky, inefficient, or expensive?

2 Answers

up vote 4 down vote accept

A 12V adapter that can source 1000A would need to be connected to at least a 120V 100A supply or a 240V 50A supply, in either case much larger than your wall outlet can deliver.

up vote 3 down vote

All of that. The most simple example is that the cable has to handle 5000 Amp. That's going to be a massive cable. I don't mean as thick as your arm or leg, it's worse than that.


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DC adapters: why so few amps?

up vote 14 down vote

If I have a device that draws 5 amps at 12 volts, I can use any 12 volt DC adapter that can provide at least 5 amps.

Why don't all DC adapters have the capacity to provide loads of amps!? If all DC adapters provided e.g. 1000 amps, we would only need to care about the voltage value.

Do too many amps make DC adapters bulky, inefficient, or expensive?


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up vote 9 down vote

A 12V adapter that can source 1000A would need to be connected to at least a 120V 100A supply or a 240V 50A supply, in either case much larger than your wall outlet can deliver.

edit

@Snowman, that is an idea, but it's a pretty bad one. The War of Currents should have taught us that... but maybe we've forgotten our Edison/Tesla history. Even Volkswagen and its famouse 6V electrical system should have been a good lesson, and a more recent one as well. - TDHofstetter Aug 28 at 3:36

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