A half wave gap in input power results in an exponential decay in output during that period as the magnetic field collapses.
It already collapsed because input voltage is zero. There is nowere to get power to create full halfwave that is missed.
Not all UPSs use relays, some designs use power switching semiconductors with a far faster switching time and they can respond a lot faster than either a mechanical contact or 1/60 of a second half cycle time which is 8 milliseconds
Most "smart" UPS have dealy while switching from mains to battery and back not because of speed of switching device, but because of unsyncronized mains and internal DC-AC converter. Imagine mains power disappear at the top of sine wave, while DC-AC converter is at the bottom. You will have a problem with twice of grid voltage rapid swing with all consequences. So, UPS have to wait while its DC-AC converter output will reach zero to safely switch to it. Usually things are even simplier - if mains disappear, UPS just switch to DC-AC convertor and start it. This takes time. Also many use the same transformer for mains voltage stabilisation and charging and for DC-AC converter that also limits speed of switching.
UPS manufacturers cheat with speed of reaction to power grid changes, showing time of reaction for grid voltage stabilisation mode, which is done by switching between additional transformer winding parts that does not need any delay or sync, and not for switching from grid to battery and back.
I saw "smart" UPS that constantly run separate DC-AC converter in sync with grid, to make the switching process fast and safe, but they are not a cheap ones you usually see on the market and cost a little less than normal online UPS that just have no any switching process at all.
"It already collapsed because input voltage is zero. There is nowere to get power to create full halfwave that is missed."
You miss the point and may not understand physics too well. Inductors are inductors because they store energy in a magnetic field. When the input voltage is removed, current keeps flowing because the collapsing field keeps charge moving. That current causes its own EMF - voltage - which drops in an exponential way as the mathematics shows.
Your explanations are jumbled, I figure you are a technician but not an engineer or a physicist.
Inductor for current is like capacitor for voltage. It will continue to push current when it drops and resist current when it rises. In no way it can restore missing half wave.
In line conditioners that usually sold everywhere, if you ever disassembled one, you will see a relatively small inductors on each wire or a common mode choke with capacitors before and after. Somethimes semiconductor surge protectors (varistors) added. This circuit is mostly for supressing noise in power line and cutting noise that could come from devices you connect to it, and if it have supressors nothing more. In no way inductors and capacitors used could store enough power to restore somehow missed half wave. It is just a HF filter, usually designed to cut frequencies higher than 2kHz, nothing more.
Just tear down one and see that by your own eyes. You could even easily measure frequency characteristcs if you have a tunable frequency generator and multimeter.
Line stabilisers, are another beasts that switch windings when grid voltage drops or rises, to keep output in limits, they can't restore missing half wave too.
No one said the inductor will restore a missing half wave - I said it responds in a certain way putting out energy after input power goes away. All it takes is a fraction of a cycle time to do that, but it allows any battery fallover power source being activated to drive to any DC to AC generation circuitry. Which can be activated very rapidly, being semiconductor based, and within a fraction of cycle time.
I believe now you are a technician parading authority, so enough of this.
Which can be activated very rapidly, being semiconductor based, and within a fraction of cycle time.
Of course it can. But should not. Imagine, mains power disappear at the bottom of AC sine. You had -110 V on the hot wire at that moment. Then, you start DC-AC converter that starts from top of AC sine at +110 V on the hot wire.
Guess, would be your devices glad if they suddenly get a surge from -110V to +110V "within a fraction of cycle time.". What if you have some inductive or capacitive load on the UPS output?
That is why there is a delay in switching from mains to battery or vice versa in cheap UPS.
Just take oscilloscope and check how that works if you are in doubt.
It already collapsed because input voltage is zero. There is nowere to get power to create full halfwave that is missed.
Most "smart" UPS have dealy while switching from mains to battery and back not because of speed of switching device, but because of unsyncronized mains and internal DC-AC converter. Imagine mains power disappear at the top of sine wave, while DC-AC converter is at the bottom. You will have a problem with twice of grid voltage rapid swing with all consequences. So, UPS have to wait while its DC-AC converter output will reach zero to safely switch to it. Usually things are even simplier - if mains disappear, UPS just switch to DC-AC convertor and start it. This takes time. Also many use the same transformer for mains voltage stabilisation and charging and for DC-AC converter that also limits speed of switching.
UPS manufacturers cheat with speed of reaction to power grid changes, showing time of reaction for grid voltage stabilisation mode, which is done by switching between additional transformer winding parts that does not need any delay or sync, and not for switching from grid to battery and back.
I saw "smart" UPS that constantly run separate DC-AC converter in sync with grid, to make the switching process fast and safe, but they are not a cheap ones you usually see on the market and cost a little less than normal online UPS that just have no any switching process at all.
"It already collapsed because input voltage is zero. There is nowere to get power to create full halfwave that is missed."
You miss the point and may not understand physics too well. Inductors are inductors because they store energy in a magnetic field. When the input voltage is removed, current keeps flowing because the collapsing field keeps charge moving. That current causes its own EMF - voltage - which drops in an exponential way as the mathematics shows.
Your explanations are jumbled, I figure you are a technician but not an engineer or a physicist.
Inductor for current is like capacitor for voltage. It will continue to push current when it drops and resist current when it rises. In no way it can restore missing half wave.
In line conditioners that usually sold everywhere, if you ever disassembled one, you will see a relatively small inductors on each wire or a common mode choke with capacitors before and after. Somethimes semiconductor surge protectors (varistors) added. This circuit is mostly for supressing noise in power line and cutting noise that could come from devices you connect to it, and if it have supressors nothing more. In no way inductors and capacitors used could store enough power to restore somehow missed half wave. It is just a HF filter, usually designed to cut frequencies higher than 2kHz, nothing more.
Just tear down one and see that by your own eyes. You could even easily measure frequency characteristcs if you have a tunable frequency generator and multimeter.
Line stabilisers, are another beasts that switch windings when grid voltage drops or rises, to keep output in limits, they can't restore missing half wave too.
No one said the inductor will restore a missing half wave - I said it responds in a certain way putting out energy after input power goes away. All it takes is a fraction of a cycle time to do that, but it allows any battery fallover power source being activated to drive to any DC to AC generation circuitry. Which can be activated very rapidly, being semiconductor based, and within a fraction of cycle time.
I believe now you are a technician parading authority, so enough of this.
Of course it can. But should not. Imagine, mains power disappear at the bottom of AC sine. You had -110 V on the hot wire at that moment. Then, you start DC-AC converter that starts from top of AC sine at +110 V on the hot wire.
Guess, would be your devices glad if they suddenly get a surge from -110V to +110V "within a fraction of cycle time.". What if you have some inductive or capacitive load on the UPS output?
That is why there is a delay in switching from mains to battery or vice versa in cheap UPS.
Just take oscilloscope and check how that works if you are in doubt.