What is the part of a Universal Power Interrupter that actually detects no power

[jratftcc]

Does anyone know what the part(s) are called that a UPS uses to determine when theres no power and it should kick itself on to supply power from its own power supply?

Also, anyone know how the UPS detects a return to regular power, and switches itself off to allow the electric company
power to resume offering power?

Thanks

[cmiyc]

https://www.google.com/search?q=how+do+ups+work

[jratftcc]

James - that link didnt help any.
It doesnt specify what the mechanism for the switchover is.

I'm hoping to find what the exact aparatus is that detects no power and then switches to battery power.
As well as the means of which it flips back to its regular constant source when it detects current has been restored.

Anyone else?

[cmiyc]

The second link on my results is a wikipedia page that goes into extreme detail of different designs of UPSs work.

[GoForSmoke]

Simplest kind have power coming in to charge a battery and power going out comes from the battery. If line voltage goes out then the battery simply stops being charged.

Other kinds are SPS, Standby Power Supply. That kind switches the battery in when line power goes off. Before 1990 I was told there was a very short time with no power as opposed to a UPS, Uninterruptable Power Supply. Affordable technology has improved since then.

[jratftcc]

Okay, I think you guys are missing the point of the question.

Im asking if anyone can help out with the namr of the exact device, instrument or aparatus that does the switcing.
Is it some type of relay switching unit, or what -- I do not know.  I already understand the principles of battery backup with the different types of backup units there.

what exactly does the switching over is what Im trying to determine.
Thanks to the guys that help out

[cmiyc]

No, you are missing the point.  There isn't a magic "UPS Switch detect device."  It is a system of circuits that monitor and react (depending on the ups implementation).  Which is well explained in the wikipedia article.

The actual switch device is a MOSFET or IGBT.

[retrolefty]

There are different methods that specific UPS systems use to perform their function. In one classic method there is no switch required as the UPS stages consist of:

Input rectifier: Converts utility supplied AC power to some DC voltage
DC link: has a battery and the rectified AC power connected to together
Output inverter: This converts the DC link power back to AC voltage to power the protected loads.

If the input AC fails the DC link is still powered by the battery bank so the load sees no change and no physical switching needed to be done. And when AC input power returns it just starts supplying the DC link voltage.

Now there are lots of details like how the battery bank is charged and maintained while there is input AC available. And there is usually a need to switch off the load when there is no input AC and the battery bank is expended, usually with a output relay or SCR/Triac devices.

Again there are other methods used and some do have physical switching devices, again usually SCR or Triac based, but without looking at a specific USP design it's hard to give general answers that hold true for all UPS designs.

Lefty

[GoForSmoke]

Okay, I think you guys are missing the point of the question.

Im asking if anyone can help out with the namr of the exact device, instrument or aparatus that does the switcing.
Is it some type of relay switching unit, or what -- I do not know.  I already understand the principles of battery backup with the different types of backup units there.

what exactly does the switching over is what Im trying to determine.
Thanks to the guys that help out

wall power ====>> charger ====>> battery ====>> inverter ====>> PC

There is no switch. As long as there is wall power, the battery is kept charged while the PC runs.  
If wall power fails, I can run my PC about 15 minutes on just the battery. Power usually reroutes in minutes around here but sometimes much longer. 15 minutes is warning to close operations and prepare for shutdown unless power returns.

It's like having a magic beer mug that stays full as you drink. If the magic stops, you still have a full mug of beer. If/when the magic comes back, the mug will soon be full again.

PS I just wondering if anyone had to pause a few beats over the thought of such a mug.

 

[retrolefty]

PS I just wondering if anyone had to pause a few beats over the thought of such a mug.

I want one please!

Lefty

[zoomkat]

what exactly does the switching over is what Im trying to determine.

Perhaps post a link to this "Universal Power Interrupter" (interrupter?) to which you refer so there is a better idea of to what you are referring.