So called "smart" UPS produce glitches too. When grid power is OK, they connect it to the output directly. On the power loss they switch to battery powered DC-AC converter or switch additional windings on power transformer. For price saving reasons they do it with relays. All that processes create noticeable glitches in output. Moreover, to avoid need for syncronisation of grid frequency with DC-AC converter ones, "smart" UPSes usually skip at least half of AC period while switching from mains to battery and back.
I don't even mention all that "line conditioners" They perfectly pass half wave gaps that gives noticeable glitch on the output of loaded power supply. They are fine only for cutting high frequency noise from power grid.
So, only online UPS are useful for real protection against glitches, since they always create output from scratch (48-96V DC) using their DC-DC and DC-AC converters, so nothing from input could crawl to the outpur and switching from mains to battery and back is seamless.
I dispute some of that. Line conditioners rely heavily on power stored in the magnetic fields of their inductors. A half wave gap in input power results in an exponential decay in output during that period as the magnetic field collapses. Where did you get the 'perfectly pass half wave gaps' from? That's untrue.
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. Any input power dropout obviously detectably occurs within that time framework and requires a response time in the range about 1 to 4 ms, perhaps a 1/4 cycle period.
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.
So called "smart" UPS produce glitches too. When grid power is OK, they connect it to the output directly. On the power loss they switch to battery powered DC-AC converter or switch additional windings on power transformer. For price saving reasons they do it with relays. All that processes create noticeable glitches in output. Moreover, to avoid need for syncronisation of grid frequency with DC-AC converter ones, "smart" UPSes usually skip at least half of AC period while switching from mains to battery and back.
I don't even mention all that "line conditioners" They perfectly pass half wave gaps that gives noticeable glitch on the output of loaded power supply. They are fine only for cutting high frequency noise from power grid.
So, only online UPS are useful for real protection against glitches, since they always create output from scratch (48-96V DC) using their DC-DC and DC-AC converters, so nothing from input could crawl to the outpur and switching from mains to battery and back is seamless.
I dispute some of that. Line conditioners rely heavily on power stored in the magnetic fields of their inductors. A half wave gap in input power results in an exponential decay in output during that period as the magnetic field collapses. Where did you get the 'perfectly pass half wave gaps' from? That's untrue.
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. Any input power dropout obviously detectably occurs within that time framework and requires a response time in the range about 1 to 4 ms, perhaps a 1/4 cycle period.
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.