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is 2A=200mA? Answered

I have a a wall plug to dc power supply that outputs 12V/2A , I also have a security camera that's input is 12V/200mA.

is it safe to use these together?



2 years ago

2A = 2000mA Yes. Camera draws the amps that it needs. Just make sure the volts (electrical pressure) is the same. (in some cases, if you know what you're doing, you can fudge the voltage ratings a bit too. I have a composite security camera that nominally requires 12V but will still function down to 7V. before the signal got crazy and stopped).

2A does not equal the value the OP stated, ie, 200mA

OP asked "is 2A =200mA" I corrected that by saying 2A = 2000mA.

"2A = 2000mA Yes." is a confirmation, not a correction.

So in what way is that seemingly trivial mistake going to confuse anyone? I honestly fail to recognize the logic behind your arguing.

I was not arguing, I corrected you.

Nope, 2A = 2000mah

An "Amp" is a thousand mah (milliamps)

It is totally safe to use, 100% :)

nope, a milliamp is 1/1000th of an amp., you're off by a factor of 10.

Any time you see 'milli' in front of a mathematical/.scientific value, think 1/1000th.

centi is 1/100th (rarely if ever used when speaking about amperes

deci is 1/10th (rarely used as well)

micro = 1/1,000,000 (all the time ..capacitors for instance

nano = 1/1000,000,000 (same used frequently)

pico = 1/1000,000,000,000

That's right. In the SI system, Centi and deci are either forbidden or deprecated, as you point out. The only permissible multiples are 1000 and 1/1000.

Did CGS permit centi- and deci- ?

I don't recall specifically, I do vaguely recall some school homework and problems back in junior high, highschool and even a few in college that referred to to centi and deci, which seemed ok when I was a teen but as a college student found myself a bit confuzzled by (as in "Why are they using this?, not "What does that mean?"). Since the OP clearly isn't familiar even with "milli" in the first place, I figured I ought at least broach the subject.

Since CGS is ?centimeter-gram-(something or another), yes, I suppose it would, at least centi. Deci is still used indirectly (ie decimation in A/D conversion), and of course "deci"mal numbers, but afaik I've never seen a decimeter used in a real world application just in reference for learning the basis for the divisions. idk not terribly important the grand scheme

Is it safe to use them together?

If you had more courage, you would not have to ask someone first. You'd just connect them up, then watch for smoke! Ha!


The current rating on the DC supply is a maximum value, the maximum current the supply can comfortably supply. It can also comfortably supply any current in between 0.000 A and this maximum value, of 2 A = 2000 mA.

The current rating on the camera is probably also a maximum, the maximum current it will draw when it has all its gizmos and ding-dongs turned on at once. It might draw less than that when just the gizmos are turned on, and the ding-dongs are turned off.

Because 200 mA is less than 2000 mA, I expect the camera and this power supply to be very happy together.

So you should connect them together, and see if they play nice.

If you want to be extra-cautious, make sure you've got the polarity right first.

Yes, its safe. The camera will draw what it needs, the supply can feed it