AC Adapter - wrong amperage?

My dvd player's ac adapter died, and while your forum on opening it up to fix it was great, it is not a simple short that can be soldered. This is a basic electronics 101 question. The old adapter put out 9v 2.2 a. I have an adapter that puts out 9v 3.0a that fits. Will I fry the dvd player by trying it out? or will it only take what it needs? Thanks for your advice. JB

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jaybesq (author) 9 years ago
Thanks gang! It worked like a charm. I am very happy I listened to your advice re: the voltmeter! The wire marked on one adapter was positive, and the other negative. Coulda blown the whole thing. Thanks again.
gmoon9 years ago
Yes. The rating indicates it's potential to safely supply amperage up to that rating. If the device doesn't draw that much power, no problem.

Unregulated supplies can be a problem if you attached a device with a low current draw, like 50 milliamp (0.05 amp) to a 3 amp supply. But that's not an issue with your player.

Just be sure the new plug is the same polarity (+,-) as the old one...
jaybesq (author)  gmoon9 years ago
Thank you so much! Lemme see if it works...... Arggh, wrong size plug at the end. Gotta chop and splice. The polarity, according to the diagram on the adapter itself is the same. Now I gotta hope that when I splice they are meant for each other + vs -. One of the adapters has mini writing on one wire, and the other has a line marking one wire. That is universally accepted as meaning the same wire?
> One of the adapters has mini writing on one wire, and the other has a line marking one wire. That is universally accepted as meaning the same wire? . A very common convention, but not universal. Check with a voltmeter to be sure.
jaybesq (author)  NachoMahma9 years ago
Just curious, could the results of a wire swap be disastrous? Or it just won't work so no biggie - I'd just switch them around... Like accidentally putting the batteries in the flashlight the wrong way, no problem?
. If you're working with AC, there is no polarity. Double-check the player and adapter and make sure they both are AC or DC. No mixing. . If DC, then see gmoon's comment about protection diodes. Ie, maybe... maybe not. Double-check before applying power. . BTW, incandescent bulbs (non-LED flashlights, "old" home light bulbs) don't care if they get AC or DC, or what polarity the DC is.
gmoon jaybesq9 years ago
Depends on the device. Some have a "protection diode" in the circuit. If you apply reverse polarity, the diode blocks any current and prevents damage. But the diodes is often NOT added when the manuf supplies the power adapter--the logic being that it's impossible to connect it up wrong IF you use their adapter. Plus it's cheaper.... As NM wrote, check first.