Speakeasy forum

General discussion

AC Universal Power Adapter

by Walt H / March 20, 2008 1:24 AM PDT

I have an AC/DC Universal Power Adapter which outputs up to 12 V DC. Shouldn't this work with any device which recommends 12 V DC?

A certain company (I won't name) request that I purchase THEIR Universal Power Adapter for their paticular device.

Discussion is locked
You are posting a reply to: AC Universal Power Adapter
The posting of advertisements, profanity, or personal attacks is prohibited. Please refer to our CNET Forums policies for details. All submitted content is subject to our Terms of Use.
Track this discussion and email me when there are updates

If you're asking for technical help, please be sure to include all your system info, including operating system, model number, and any other specifics related to the problem. Also please exercise your best judgment when posting in the forums--revealing personal information such as your e-mail address, telephone number, and address is not recommended.

You are reporting the following post: AC Universal Power Adapter
This post has been flagged and will be reviewed by our staff. Thank you for helping us maintain CNET's great community.
Sorry, there was a problem flagging this post. Please try again now or at a later time.
If you believe this post is offensive or violates the CNET Forums' Usage policies, you can report it below (this will not automatically remove the post). Once reported, our moderators will be notified and the post will be reviewed.
Collapse -
As long as
by JP Bill / March 20, 2008 1:47 AM PDT

the polarity and the size of the tip are the same AND the output mva (milli-volt amps) of the adapter are equal.

They may say that if the output is too large it might put out too much current and destroy some components in the device. The device should draw a certain amount of current when working properly and IF something goes wrong it COULD cause something else to be damaged because of the excess current..

If the output is too low it may not work.

Collapse -
My Adapter...
by Walt H / March 20, 2008 1:56 AM PDT
In reply to: As long as

My Universal AC/DC adapter is 1000mA...Device in question indicates 1500mA.

Collapse -
IF it was me
by JP Bill / March 20, 2008 2:03 AM PDT
In reply to: My Adapter...

As long as the tip was the correct polarity + on the proper part of the tip and - on the proper part of the plug

I would try it.

Collapse -
i would double check if i were you
by jonah jones / March 20, 2008 2:27 AM PDT
In reply to: My Adapter...

if the device wants 50% more than you have.....

to quote from wayne hardy:

Smoke Defined
All electronic components are carefully designed and have smoke added. Many man hours and dollars are needed to place the smoke inside each and every piece, from resistors, to transformers, to diodes. It's very time consuming and labor intensive, but thankfully the smoke doesn't add to the cost. It's an added perk, and the smoke actually makes the components and devices work. In fact, smoke is critical to the operation of the device or component. That's why when you let the smoke out; the device doesn't work any more.

Collapse -
How to troubleshoot electronic devices
by JP Bill / March 20, 2008 2:34 AM PDT


Smell .........(check for smoke)

Hammer and tong (repair)

Collapse -
(NT) I should add touch...check for excessive heat on transformer
by JP Bill / March 20, 2008 2:39 AM PDT
Collapse -
A fork to check electrical flow is a must.
by grimgraphix / March 20, 2008 5:53 AM PDT

When a fork is not available, touching the contact with your tongue is an acceptable substitute.

Uh... you need to know this is not a comment from any sort of trained (or even competently sane) individual.

Collapse -
it might help if we knew what the device is
by WOODS-HICK / March 20, 2008 10:56 AM PDT
In reply to: My Adapter...

is there a motor? or strictly electronics, no mechanism?

amperage is the current drawn to make something work.

example: 1kw light bulb requires 8.3A

my cordless answering machine requires: 9v 350mA. the device also says to use only the manufacturers transformer. I assume one of the pins on your adapter fits and makes contact. that is a possible reason why you have to use a specific adapter.

as mentioned earlier you do not want to lose the irreplaceable smoke. also temperature is a good guide but it might be too late: touch the device and the adapter: often.

Collapse -
Easy way to remember...
by J. Vega / March 20, 2008 12:36 PM PDT

An easy way to remember it is "simple as pie". P (power in watts)= I (amperage in amps) times E (energy in volts). P=IE

Collapse -
thanks, here's another aid
by WOODS-HICK / March 20, 2008 1:10 PM PDT

here's a handy calculator:


at work line voltage was usually 120-125, or 220-240. generators had adjustable voltage. AC/DC were both used.

and we knew the wattage of most of the devices.

so Amps was our main concern. as they say it is not the volts but the Amps that kill you. there is a big difference in the shock between a conductor that is idle and one that is drawing current (Amps).

the above is a generalization and lower than household current may still kill you.

Amps are also important to determine the size of the conductors (prevent that smoke release) and proper phasing and breaker capacity.

I never worked much with solid-state or low-voltage electronics. if I couldn't figure it out and it was not cheaper to keeper, replaced it.

Collapse -
An easier way to get across...
by J. Vega / March 20, 2008 1:22 PM PDT

An easy way to get across the amps/volts relationship is to think of it like water hose. Imagine somebody washing his car with a garden hose. It would be silly to say, "Watch out, that hose is connected to a billion gallon reservoir!". No danger, the rate of water flow is limited by the rate that the hose can move water. The reservoir is the "potential", or volts. The rate of flow possible with the garden hose is amps.
Now connect a fire hose to the fireplug ans turn it on. You are connected to the same reservoir (volts), but the rate of flow (amps) will knock someone on his rear end.

Collapse -
that is true and plumbing is often used as an example
by WOODS-HICK / March 20, 2008 1:46 PM PDT

for electrical circuits. it sounded like you knew what you were talking about. I was speaking of my personal experience. I have never been a fireman, but I have witnessed 4/0 connectors melting. I have blown the ends off tie-ins in a service panel. I have seen the smoke get out.

Collapse -
At a union meeting
by JP Bill / March 20, 2008 1:56 PM PDT

One of my brothers stood up and said that he had

hooked up many motors and blown up a few motors.

I suppose now some will think I have a "brother" that is an electrician.

Collapse -
(NT) better than a plumber, brother
by WOODS-HICK / March 20, 2008 2:26 PM PDT
In reply to: At a union meeting
Collapse -
Want to talk expensive smoke....
by J. Vega / March 20, 2008 2:09 PM PDT

Want to talk expensive smoke? How about an idiot camera operator who plugs in a $75,000 110v television camera into 220v? Forget fuse, it arced across the fuse housing. Gets better. After no end of trouble getting it fixed immediately, the next day he did it again. I told him that if I Ever saw him so much as picking up a plug adapter I'd do violence.

Collapse -
was he or she in the union?
by WOODS-HICK / March 20, 2008 2:24 PM PDT

where I worked I don't think he or she would have got a second let alone a third chance.

who wired the stage? 220 isn't usually readily accessible. if it is it requires a different plug. are you sure it wasn't the caterer who plugged it in. Happy

also on union shoots, camera operators don't plug in anything without checking with the gaffer or an electrician. also the assistant cameraperson usually does those tasks.

documentaries and low-budgets do not always have the luxury of union personnel.

Collapse -
by J. Vega / March 20, 2008 2:35 PM PDT

No, it was a television network. He was the talent's favorite cameraman. I was the field engineer filling in for the regular one, who was sick. I got out "Don't..". It was overseas (Italy), and 220 is all over the place. Yes, it had a different plug, but instead of using the 110 line I obtained, he grabbed an adapter.

Collapse -
that will make sparks
by WOODS-HICK / March 20, 2008 4:08 PM PDT
In reply to: No...

I never worked on a TV stage, different local. if an actual TV show was part of a scene we would bring our own power and stage boxes etc in. the crews always remained separate but equal in responsibilities. sorta like two teams playing on the same side to produce an outcome.

most of the time the camera department on movies, etc. would use battery power. always if we were on a genny. that also prevented 'air-gaps' AKA a kicked out plug. connections were taped and we added strain reliefs. if a scene was going to be long they would switch out and go to fresh batteries. we supplied the AC for them to charge, and we would mark any box that was not 125v. the newer boxes have 220 twist receptacles, no adapters ever allowed. so if it was not 125v it was our butts on the line. protocol expected an electrician to plug in all electric devices on a set. in the long run it is safer and cheaper.

at the time the most powerful tungsten quartz lamp was 20kw, 220AC or DC. a major reason to know amperage.

Collapse -
a plug adapter
by JP Bill / March 20, 2008 2:34 PM PDT

He wasn't using a plug adapter, was he?

Why would they even make an adapter to enable the plugging in of a 110 volt device into 220 volt receptacle?

Collapse -
They make them...
by J. Vega / March 20, 2008 2:37 PM PDT
In reply to: a plug adapter

They make them for using 110/220 switchable devices when you go overseas.

Collapse -
(NT) They make them..........An accident waiting to happen
by JP Bill / March 20, 2008 2:42 PM PDT
In reply to: They make them...
Collapse -
You've got to be careful...
by J. Vega / March 20, 2008 2:49 PM PDT

You've got to be careful. Got a tower desktop computer? Look at the back of it - the power supply. It's quite common for them to have a little switch (usually red) that says 110v. You might find that it can be slid to a 220v position. If you check, do it when the computer is unplugged and immediately Put It Back where it was.

Collapse -
Radio Shack....
by C1ay / March 20, 2008 3:22 AM PDT

used to carry one that was switchable between several voltages, came with several different tips and had reversible polarity. If they still carry it then it might work for your application.

Collapse -
Several Tips
by Walt H / March 20, 2008 3:47 AM PDT
In reply to: Radio Shack....

I have one with several different tips and switchable voltages.

Popular Forums
Computer Newbies 10,686 discussions
Computer Help 54,365 discussions
Laptops 21,181 discussions
Networking & Wireless 16,313 discussions
Phones 17,137 discussions
Security 31,287 discussions
TVs & Home Theaters 22,101 discussions
Windows 7 8,164 discussions
Windows 10 2,657 discussions


Help, my PC with Windows 10 won't shut down properly

Since upgrading to Windows 10 my computer won't shut down properly. I use the menu button shutdown and the screen goes blank, but the system does not fully shut down. The only way to get it to shut down is to hold the physical power button down till it shuts down. Any suggestions?