does the display stay on?
Hi, does the display showing the voltage stay on? thx!
Thanks for the info 
Good analogy, as that defines what I guess I don’t understand, and that is what are the ‘transients’?
I have another dumb, non EE question. My current setup is home theater, gaming consoles, etc. running into an APC Back-UPS unit - each device more or less having their own plug (albeit “cheating” a little using a cord dongle because only half of the plug ports are batt.backup). But if I ran all my components into this thing, which in turn ran back into my UPS via a single plug, will this overload the plug port on the UPS?
Generally most people will tell you that plugging a powerstrip into a UPS isn’t a good idea. However, I have been doing it for many years with my home computer and peripherals just because it is easier to manage the cords/plugs. I don’t game so my stuff doesn’t draw that much current so I’ve never had a problem.
However, I would be more wary of plugging your receiver and subwoofer amps into a UPS. You need to check how much current you can draw from that UPS to see if it could either limit your draw or cause some other issue. If you have a kill-o-watt that you can use measure your amps and watts you’re using when running your stuff you should be able to compare that to what the UPS is rated to output.
stupid question here… but, I live in Florida and the power goes out all the time from nasty storms. I just have a nice TV, a PS4, and an apple tv… the rest is cable equipment that I don’t really care about. Is this something I could use? Or is this for like serious stereo component setups? I already have a surge protector but outlets are on top… it would work out much better with this horizontal version i think.
One of my many hats is an electronic tech. All transformers will work on a 2 prong as the white wire is ground. The 3rd green wire ( shield ground) is tied to the white wire in the breaker panel.
Also, where is the max wattage rating on this unit? Most of my AC strips are rated 1500 to 1850 watts max. That should be in the specs but I don’t see it. Maybe because it’s under 1000 watts? Hmmm.
The better strips such as this one, uses a choke and capacitors for noise reduction and a metal oxide varistor (MOV) for the spikes. One of my MOV’s blew when the power line had a lighting strike, so yea, it might save your equipment. I replaced it with a new MOV for 85 cents
Not exactly. In the US, the single-phase 120 VAC mains has the black wire as hot and the white wire is neutral. While it is true that the neutral is bonded to ground back at the panel, it is a current-carrying conductor. In EE terms, the neutral is the return for the hot, which means that while the voltage on the neutral is 0 V (with respect to ground), the current in the neutral is equal to the hot current in amplitude but of course reverse polarity.
The safety ground, the green wire, goes back to the panel separately from the neutral at the output. It is not a current-carrying conductor in normal operation, but of course it has to carry the load current in case of a fault (at which point it will force the breaker to trip).
Watch out with MOVs, though. They certainly do their job in the event of a lightning strike, but they are a sacrificial element. They are always absorbing little spikes, too, and as they do that, they degrade and get leaky. This can manifest as a difficult-to-understand noise problem (a hum in your audio, odd lines/patterns in an old CRT display), and what’s worse is that they’ll do this even with nothing plugged into the power strip!
As was referred to later, a clean common ground (neutral/white wire) is most important. The phase of the 120V RMS (177V peak) supply can be different at different outlets because of the split 240V RMS supply voltage that most houses have. Most amplifiers convert the AC to something like 80V DC so as long as there is enough voltage and current to power the DC conversion the peak voltage doesn’t matter.
The EMI filter helps remove noise from the common ground line.
Load dumps from large inductive loads are a major cause of the ground noise.
My analog stereo does have a transformer but most digital AVR’s now use a switched mode supply as was mentioned - and a digital class D amp instead of analog class A.
You are referring to a GFCI breaker, which doesn’t work with inductive loads because of the ground noise. A normal breaker only protects against an overcurrent conditon.
The ground noise generally doesn’t cause damage, just noise that can be filtered out for sensitive electronics.