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I have a wireless router that needs a 12VDC 1A power supply. I no longer have the power supply for it. Is there any harm in using a 12VDC 1.2A power supply instead?

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closed as off topic by Zoredache, Ward, voretaq7 Apr 30 '12 at 18:53

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Does the plug fit, does it have the correct polarity? – Zoredache Apr 30 '12 at 17:15
Yes. The plug fits. – Tom Apr 30 '12 at 17:45
So the question is are you willing to risk releasing the magic smoke. If yes, then plug it in and see. – Zoredache Apr 30 '12 at 18:15
If you're seriously asking this question I'm going to assume you're asking about a consumer/home router (D-Link. Linksys, Netgear), and not a "real" router (Cisco, Juniper) which typically takes mains voltage directly without a wall-wart. While consumer hardware is not strictly verboten here the best thing we can tell you is "Check the polarity, try it and see, and be aware that you're almost certainly voiding your warranty." -- further questions about this warranty-voiding activity are probably better suited to Super User :-) – voretaq7 Apr 30 '12 at 18:55

Make sure the plug fits and the polarity (+/-) is the same.

More AMPs should be OK as long as you are not massively overdoing it. In general, as long as the power-supply is not more than 150% heavier, you are save.

More Volts is another matter. Don't do that unless there if a fire-extinguisher handy.

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Right, over-amperage should not be an issue in close cases like this. Voltage normally has some tolerance as well but be careful. – Jeff Apr 30 '12 at 18:19

Technically, it's fine, providing the polarity is correct, it uses the same voltage and has a higher current rating than the device draws.

From a safety perspective, it depends. If the device is protected by fuses, it should be okay, however if it isn't and a fault develops, the device could draw the maximum current the PSU can provide, which could cause a fire if the device isn't rated to handle that level of current.

I wouldn't worry about getting a PSU that is rated slightly higher than the current draw of the device, but if in doubt, hit your local electronics component retailer, who should be able to supply you with the correctly rated PSU.

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I have tried this before and it didn't work as expected.

  • Same polarity
  • Same voltage
  • Different AMP

It started to boot but failed with some LEDs stuck on. I assumed that the sightly higher amp rating altered one of the timing frequency.

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The difference matters. If you have more supply the demand then things should work. If you have less supply then demand you may release the magic smoke, or see some other failure. – Zoredache Apr 30 '12 at 18:13
I was only sharing my own experience of the exact same situation. – Christopher Hackett Apr 30 '12 at 19:13

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