All Questions
22
questions
0
votes
1
answer
75
views
What fire tests are done on power adapters/chargers?
I was curious about the fire risks in using a typical AC-to-DC wall adapter
(e.g., this)
and went to the UL website
to learn what exact tests were done to get the "UL LISTED" stamp,
but I ...
- 554
0
votes
2
answers
384
views
In AC/DC adapters, why can't the DC cable be detached from the adapter?
I notice that in most (all?) AC/DC adapters, the DC cable can't be detached from the adapter. Is there a reason for that?
Example:
Note: The question is not opinion-based, since the existing answers ...
-2
votes
1
answer
2k
views
What is the power consumption of a 12V adapter running 4 CPU fans?
I have a quick question here.
I am not a ECE guy and just a hobbyist trying to tinker while quarantined.
I have 4 CPU fans (120mm) laying around and I'm trying to re-purpose them as a small fan.
...
- 101
1
vote
1
answer
11k
views
Is it safe to use a 19V DC adapter for a 12V input if it can provide enough watts? [duplicate]
I have a small TV which expects 12V DC at 34W. Can I use an adapter with a higher voltage rating (19V for example) as long as it can provide enough amps to satisfy the amount of watts needed by the TV?...
- 2,885
2
votes
4
answers
3k
views
Converting Christmas Village from DC to AC
So this was the year we bought a AC-powered O-gauge Lionel train and a battery-operated village to add to our Christmas tree decor. The problem, the village eats batteries like a kid eats cookies.
...
- 21
2
votes
1
answer
4k
views
Function of the Third Pin Inside Laptop Barrel Connector
So I've been doing research on barrel pin connectors, and have been trying to apply this knowledge to understand laptop barrel connectors, specifically. My confusion relates to the function of the ...
0
votes
2
answers
852
views
DIY electromagnet using copper wire and AC adapter
I want to make for some demonstration (caching some paper clips on ON and doping them on OFF) electromagnet made from copper wire (should it be single wire?) with ferromagnetic inside coil:
As power ...
- 187
0
votes
7
answers
8k
views
Calculate the electric bill of a phone charger (AC adapter input or output?)
I need to calculate the amount of money I pay for charging my phone with this charger
I know that I need to calculate the watts then kWh, so I multiplied 5 V by 1.55 A to get 7.75 watts and then use ...
- 5
0
votes
2
answers
2k
views
Simple circuit to detect ac power loss and use dc backup? [closed]
I want to make a simple circuit like those used in commercial emergency lights.
I would have a "walmart" AC to DC adapter powering say a DC light or two. I would like it so when the AC powering the ...
- 41
1
vote
2
answers
3k
views
What is the purpose of all these resistors and capacitors in this power supply? [closed]
This is the schematic diagram of pa-12 family laptop adapter. I think it is based on flyback topolgy but i have a problem understanding many things in it.
Actually, in many circuits in general ...
- 1,491
3
votes
2
answers
13k
views
AC Adapter gives much more voltage than it's supposed to [duplicate]
Hello!
I have this one older AC-DC adapter from Korg (wallwart?)...
...that I have been using for my (guitar) effect pedals for a few years, and I recently found out (when I was doing some ...
- 167
-1
votes
1
answer
2k
views
Connecting two DC voltage sources in series
I need a 42 volt DC supply to check a motor. All I have is one 30V DC source and a few rated lower than this.
Is it possible for me to connect the 30V source and a 12V source in series to get the ...
- 61
1
vote
1
answer
128
views
Power adapter efficiency standards, any drawbacks?
Supposedly, some new federal regulation is imposing "energy efficiency" standards on small power adapters.
How is this going to affect electronics? Are the old types of adapters going away? If so, ...
- 2,206
0
votes
1
answer
2k
views
input current vs output current
My old/new laptop adapter specs as given below. I understand the output current for new is 4.5A which is OK when compared to old which provides 3.25A load since it can provide more load.
However, ...
0
votes
2
answers
6k
views
Is there a reason why some ac/dc adapters don't have a grounding pin?
I'm searching for an AC/DC adapter of 6v 300mA, but I can't find one with a grounding pin (E-type). Is there a specific reason for this?
