How does a single outlet power multiple electronics on a power strip? Is there a maximum limit of how many things can be plugged in?
In: Engineering
Simple answer is yes. Most power outlets are on a 15 or 20 amp circuit. So the max device for the outlet depends on the amperage draw for the connected devices. If you get over that 15 or 20 amps the breaker will trip.
In your house multiple outlets are connected to each other through the wiring in the walls. The limit to what you can plug in depends on the current draw. In a typical US house, the outlets are on a 15-amp circuit breaker, so you can theoretically plug in enough items to draw close to 15 amps into a single outlet (as long as nothing is plugged in to the other outlets).
To go a little further,
The electric service delivered to your house is capable of providing WAY MORE POWER than you could ever reasonably need. In fact, your electric service can provide way more power than any of the wires themselves can sustainably deliver so the main line can provide service to all the subscribers both at the end of the run and under peak load.
Due to inherent internal resistance in the wires, some energy is transformed into electromagnetism (all conductors are also antenna) and HEAT. When you have a closed, unimpeded circuit, electricity will flow freely. Too freely. Electrons will flow as fast as they can over the surface layer of the wire (which is why stranded wire can carry more current than solid wire), and this will raise the temperature of the wire. What happens when the temperature goes up? Conductivity goes up. What happens when conductivity goes up? Temperature goes up… And what you get is thermal runaway. The wires in your house can flash into plasma in an instant, and your house is on fire.
Enter fuses, breakers, GFCI, and ground. These devices are designed to limit the flow of current to prevent your wires from catching fire. There is also safety in limiting the amount of power that can go through a circuit because GOD DAMN what sort of industrial mixer are you running in the kitchen that needs 800A? Fuses are glorified incandescent light bulbs. If they flow too much current, they have a tungsten element, with high impedance, that will burn out, breaking the flow of electricity. The nice thing about fuses is they can’t fail. Breakers can fail, which is why you don’t see them in cars. They work by either a huge electromagnetic pulse, or by thermal deformation of a spring. You can’t just turn a breaker back on, you have to reset it, flex that spring back into shape, before you switch it back to the on position. GFCI will trip due to a huge induction load, which tends to make them incompatible with stand mixers and garage air compressors. Ground is a place to dump current that isn’t through your body and across your chest and heart, but the current will still flow high enough to trip the breaker.
All your devices have impedance and resistance, so they’ll only draw what they need. The limit to the number of devices you can plug in is set by the lowest rated segment in the circuit. So you might have a 20A breaker, but the outlet might be limited to 15A. Manufacturers also warn against overloading any one component – power strips, for example, are not supposed to have more power strips or extension cords plugged into them. And bear in mind you have to think about the whole circuit, not just one particular outlet in a room.
ac power was the solution that gave Nikola Tesla hell from Thomas Edison who was a monolithically. cruel idiot who did everything he could to sabotage alternatives much like Elon musk now. it works like a pendulum and swings one of the lines back and forth while the other line stays grounded. the two prongs in a wall are actually 0 and + and +, the third prong or ground pin is optional and is there to be extra safe by offering a local ground reference which is literally connected to earth by a rod somewhere around your house.
an ac adapter is a switch timer that simply taps into the alternating line that switches from + to – as does a clock drawing energy from a pendulum, only drawing what it needs to move the second hand.
the ac adapter works via hz rating and can multiple / transform / switch the power by as much as is needed by timing the + and – “swings”
although there is a limit to the amount of things that can be plugged into a single circuit that’s more of a bandwidth issue for fear of causing overload or fire through too much energy being drawn through a single circuit.
direct energy or dc rather than “swinging” or alternating one line and keeping one ground steady, much like how you have your feet planted in the floor to push a swing. just keeps pushing forward in a circuit. they both have their use. but it’s the timing mechanjsm that allows ac to be used like an electronics pump which allowed it to be used as a timed energy packet multiplier that made electricity transmission possible over long distances since the push and pull of the alternating line only has to flip the width of < one single electron. an electron is one stable “packet” of energy.
if you learn a bit about acoustic engineering you get a really good grasp of every aspect of how electricity works.
every circuit in your house is composed of things that have Impedance or “variable resistance” and is analogous to a pipe or valve versus pressure.
An outlet will accept as much power as you put demand on it. The only limiting factor is the circuit breaker that it’s circuit is on. The typical max load you can put on a receptacle outlet is 16A, or 1920W for a 120V circuit.
The power strip takes the hot(+), neutral(-), and ground and expands those into more outlets. In the context of the United States of America the average circuit is on a 15amp breaker. Generally speaking each room has its own breaker. So in on room you can have theoretically as many things plugged in as you want and long is it does not exceed 15amps in current draw in the room.
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