Are all wall adapters AC->DC ? - Page 1
Forum section: electronics / beginners

author: Stuartambient
author_rank: Regular Contributor
timestamp: November 20, 2016, 12:35:59 am
content: Usually they say on the label, something like DC output, but this one just says AC. Before I cut it up I just want to ask. Also it says "Common" on the label, whatever that means. Hopefully the picture is clear enough. It's possible the Chinese lettering is spelling out DC. The Chinese characters are different from Input to Output. Probably a stupid question since I figure all wall warts / adapaters are AC-DC but why not ask.

author: Zero999
author_rank: Super Contributor
timestamp: November 20, 2016, 12:41:46 am
content: The DC symbol and polarity indicator show it's DC output.By the way, it will probably work from 100V to 350VDC as it's a switched mode power supply and will rectify the mains voltage anyway.

author: Brumby
author_rank: Unknown
timestamp: November 20, 2016, 12:43:44 am
content: You can get ACoutputplugpacks - which are just a transformer - but this one is definitely DC.The marking indicated states this - but also having the polarity of the plug shown is a BIG clue.Edit: Added text in red.

author: mariush
author_rank: Super Contributor
timestamp: November 20, 2016, 12:46:38 am
content: It says right there in the middle of the label , 12v @ 1.5A ... and they show you there the negative is on the outside of the jack and the positive is in the center, so you know it's DC voltage. That dawing with a solid line and a dotted line below it is also a mark for DC voltage. You can see above at input, there's a sine wave drawing, that means AC voltage.The adapter most likely converts whatever comes in to DC using a bridge rectifier, so the minimum of 100v AC becomes a dc voltage with a peak of about 140v. So in theory you could power the adapter with DC voltage as well. I best the adapter will probably work with even lower voltages but may not "like it" .. as in make coil whine from transformer or various inductors, or overheat.That COMMON text means nothing imho, i guess it's like a brand or name of the series of the adapters from that company.

author: IanB
author_rank: Super Contributor
timestamp: November 20, 2016, 12:54:58 am
content: Quote from: Stuartambient on November 20, 2016, 12:35:59 amEveryone above has already answered your question (the output is 12 V DC, 1.5 A, center positive) ... butwhydo you think it says "AC" on the label? I have scanned the label from top to bottom and I cannot see anywhere that says "AC".

author: Brumby
author_rank: Unknown
timestamp: November 20, 2016, 01:04:40 am
content: I'm wondering if the OP is looking at the descriptor "AC ADAPTER" and getting their lead from that. Sometimes I hear the term DC adapter in discussing these things. All the same (for 99% of the time) - but one reflecting on the input and the other, the output.I'm thinking most of us are so familiar with these devices, we don't even notice little things that could confuse others.

author: Stuartambient
author_rank: Regular Contributor
timestamp: November 20, 2016, 01:19:58 am
content: Yes exactly, I was looking where it says AC Adapter and questioned it. I have a few others though that say DC. It got me good though as I should have noticed the DC symbol. Maybe it was just my eyesightbut closer to the truth is I don't look at schematics enough. The good news is I won't make that mistake again. Thanks guys!