Showing posts with label power. Show all posts
Showing posts with label power. Show all posts

Tuesday, January 31, 2017

How does a computers uninterruptible power supply UPS work

How does a computers uninterruptible power supply UPS work


A UPS generally protects a computer against four different power problems:
 
  • Voltage surges and spikes - Times when the voltage on the line is greater than it should be
  • Voltage sags - Times when the voltage on the line is less than it should be
  • Total power failure - Times when a line goes down or a fuse blows somewhere on the grid or in the building
  • Frequency differences - Times when the power is oscillating at something other than 60 Hertz  

 
 There are two common systems in use today: standby UPS and continuous UPS. A standby UPS runs the computer off of the normal utility power until it detects a problem. At that point, it very quickly (in five milliseconds or less) turns on a power inverter and runs the computer off of the UPSs battery (see How Batteries Work for more information). A power inverter simply turns the DC power delivered by the battery into 120-volt, 60-Hertz AC power.

     In a continuous UPS, the computer is always running off of battery power and the battery is continuously being recharged. You could fairly easily build a continuous UPS yourself with a largish battery charger, a battery and a power inverter. The battery charger continuously produces DC power, which the inverter continuously turns back into 120-volt AC power. If the power fails, the battery provides power to the inverter. There is no switch-over time in a continuous UPS. This setup provides a very stable source of power. 

     Standby UPS systems are far more common for home or small-business use because they tend to cost about half as much as a continuous system. Continuous systems provide extremely clean, stable power, so they tend to be used in server rooms and mission critical applications.






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Tuesday, November 15, 2016

How to Access Advanced Power Options in Windows 7

How to Access Advanced Power Options in Windows 7


Although the sole purpose of using MS Windows 7 in a powerful desktop PC is all about gaming :P... thus accessing advanced power settings makes little sense to most. But, if you use a portable device, say something like an Ultraportable Laptop or a Netbook, etc then configuring few advanced power settings concerning Windows 7 can come in handy.

When it comes to desktop UI designs it maybe true that you can learn a lot of from Apple Mac but the Gnome desktop developers can also learn a great deal from Microsoft. For instance, in Windows 7 (including Vista) Microsoft has done an excellent job of creating a pretty simple power related configuration window which is really good for the newbies since it doesnt "touch" a lot of advanced settings.

But unlike with the GNU/Linux default desktop, the Gnome, if youd rather like to have some additional control over the computer then you easily do so in Windows 7. Most of the average users like me know how to do this. But for those who dont ... this is how you access that additional configuration settings that lets you change a big list of advanced settings concerning the ACPI of your PC.

1. First click on the Batter or the Charger icon on your notification area and from the window choose "More power options" as shown in the below screenshot.


2. Then from the next window that you get, choose the "Power plan" that you want these settings to be applied and click on the Link next to it that says "Change plan settings" which should bring a new window similar to the below one.


3. From the next window that you get, look for the bottom section and click on that says "Change advanced power settings" as with below picture.


Once you click on this link you should be reveled by a new window that lets you configure a lot of advanced power settings concerning your hardware through the ACPI (advanced configuration and power interface, a standard) and using this you can change some big number of settings such as:

Note: If you click on the "Change settings that are..." (marked in Red) link, then itll only display the settings that are not available in the default/simple configuration window...
*. Manually change the Hard-Disk turning off time.

*. Pause the desktop background slide-show.

*. Change whether the Wireless adapter should give you the maximum performance or maximum power efficiency.

*. Enable/disable wake timers, change auto hibernate time or enable the Hybrid sleep mode (turned on by default for Desktops), etc.

*. PCI Express cards related settings.

*. Change Advanced Processor related settings such as: Cooling policy, Minimum processor state or Maximum processor usage limiter (which can have a significant effect on your battery life if you know how to balance things a bit :D), etc.


*. Display related settings.

*. Multimedia related settings such as : Enable/Disable media sharing, switch between performance and low power mode while playing videos.

*. Internet Explorer related Javascrpt timer setting.

*. GPU related settings.

My personal favorite is few of the settings that this window allows you concerning the battery. For instance, if youre trying to calibrate your battery then sometimes its important to let it completely drain itself (0% or somewhere near). But by default, Windows will put your Laptop into Sleep mode when it reaches a certain point in its battery life (default is 7%) which is called "Reserve battery level".


But if you forcefully disabled it then when the battery reaches about 5%, Windows WILL put your computer into Hibernate mode which in this case (were trying to calibrate the battery, remember? :D) is not what we want since wed like our battery to die to its absolute zero or close. So in that case, you can use this window to re-configure and completely disable that default action which is very handy in my experience.

But once youre done with the calibration make sure to set things in their default values since these power modes do help to recover your PC from failures. Also remember except for some (such as the mentioned "Better critical..." settings) most of these settings are automatically adjusted when you change settings in the "Power Plans window. But this configuration window gives a lot of advanced options that are sometimes necessary to get the most out of your PC nonetheless. Good luck.


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