How to protect PC against brown-outs?

[Guest]

I really don't know why but there has been 3 consecutive brown outs today. I have a surge protector but I'm worried more about losing data. What can I do about this?

[mariushm]

Get a proper UPS, that's pretty much all you can do.

 

Surge protector just protects against bad "events" by trying to filter those bad things.  An UPS will switch completely to the internal battery and produce AC power from the battery until the quality of AC input improves (or battery depletes).

[Guest]

12 minutes ago, mariushm said:

Get a proper UPS, that's pretty much all you can do.

 

Surge protector just protects against bad "events" by trying to filter those bad things.  An UPS will switch completely to the internal battery and produce AC power from the battery until the quality of AC input improves (or battery depletes).

Would cheaping out on the UPS cause problems? I'll just use it to shut off the PC properly anyway.

edit:other than battery size obviously

Edited September 29, 2020 by Guest

[mariushm]

A cheap UPS may not react fast enough, or may take too much time to turn on its circuitry and produce AC power for the computer. 

 

Computer power supplies are supposed to be designed in such a way as to survive without AC power for at least one AC cycle, or around 16 ms ... but some power supplies are made cheaper and can only work without input power for let's say 8-10 ms. 

 

An UPS is supposed to detect failure, disconnect AC input, start up internal inverter circuit (which converts 8..14v from battery to 230v AC) and then turn on the path between the inverter output and the AC socket in which the computer cable is plugged in.

A cheap UPS may take 3ms to detect failure, then 1ms to disconnect input, at least 6 ms to start the inverter circuit ... you're already at 10 ms.

 

Don't buy the cheapest and you should be fine. There's crap offline UPSes, there's middle models which are line-interactive UPSes and there's high-end "online" UPSes, which always power the AC outlets from the battery, and constantly top up the battery from AC input - these "online" UPSes never have to switch because the inverter is always on and always power the devices from clean energy, from battery... the downside is less efficiency (because any conversion is lossy) and the battery has to be replaced more often.

 

[WereCatf]

7 minutes ago, Berkomeister said:

Would cheaping out on the UPS cause problems?

The most important thing is to size the UPS correctly for your power-draw; getting a UPS that cannot handle your system's power-draw will be a waste of money as it won't protect you. Something like e.g. this meter from eBay can be used to measure your system's power-draw and power-factor, which can then be used to calculate the minimum VA-rating for a UPS (wattage / power-factor = VA-rating)