How do those devices that measure your car speed operate exactly? For over five decades police officers have been pulling over speeding drivers and handing them a ticket (or letting them off with a warning) for going over the marked speed limit.

Most typically police officers will be stationary hidden away with their police speed gun either mounted in their police vehicle. Until very recently, the radars used by law enforcement were able to detect the speed of a moving car with the Doppler effect. This method measures the change in frequency, or oscillations per unit of time.

Each part of the signal is reflected when it reaches the car, mirroring the original signal exactly. But when the car is moving, each part of the radio signal made by the radar gun is reflected at a different point in space, which changes the wave pattern. When the car is moving away from the radar gun, the second segment of the signal has to travel a greater distance to reach the car than the first segment of the signal.

While conventional radar guns are still in use across the country, many police departments are increasing the radar guns sales of LIDAR radar guns. These guns detect speed by using concentrated light and lasers. A burst of infrared light is made by the LIDAR gun and clocks the time taken to return back to the starting point. It determines how far away an object is by multiplying this time by the speed of light.

Guest post is provided by Radar Guns Sales, a trusted supplier of police radar guns. Visit the website for more details.

If you are a harassed iPod owner, this article is for you. iPods don’t always behave the way we want them to. If your iPod is behaving funnily and you have tried everything possible to repair it, without success, then a firmware re-installation might help your case.

Firmware software re-installation is an extreme measure that you should resort to only if nothing else sets your iPod right. You will have to erase your iPod for successful re-installation. It is therefore advised that you backup all your iPod data before you start this procedure.

Step 1: Erase your iPod

The protocol you implement to erase your iPod will differ based on the operating system of your computer.

1. MAC OS X. If your computer has OS X, proceed to Disk Utility (DU). DU can be accessed as follows — Macintosh HD> Applications> Utilities. Once you have the Disk Utility window open, look for your iPod in the list. Select it and then click the repair button. Next, select the Erase option to erase your iPod’s memory.

2. Windows XP. If you use XP on your computer, erasing your iPod is a straightforward procedure. Open “My Computer” and select your iPod. It will be located alongside your “C” drive. Place your mouse’s pointer on your iPod’s icon. Right click and select “Format.” From the different options that show up on the Format screen, select “FAT 32,” and then click on “Format.” Formatting will erase all the data on your iPod. Once formatting is completed, you may be prompted to reboot your computer – that’s an optional step that you’ll most probably not need to do.

Step 2: Restore your iPod

After it has been erased, your iPod is as good as new. You will have to restore it to its former glory. Start by connecting your iPod to the computer using the USB cable or FireWire that you had bought it with. Open iTunes on your computer after the iPod is connected. iTunes will automatically find the connection. It will then prompt you to install the software necessary to get your iPod up and running again.

If iTunes does not prompt, look for the “Source” column in the left half of the iTunes window. Choose your iPod in the “Source” column. Next, select the “Summary” option for your iPod. You will find it at the top of the iTunes screen along with other tabs such as “Music,” “Contacts” and “Photos.”

Click on “Restore” in the “Summary” window. If you are asked for your username and password, type them in and confirm the restore process. Your iPod’s factory settings will be restored. After restoration, remove the USB or FireWire cable from your iPod. On disconnection, your iPod will prompt you to reconnect. Use the cable and reconnect again. Your iPod will now update and restart. After your iPod has restarted, you will see a “Do not disconnect” message flashing on its screen.

iTunes will then prompt you to name your iPod. Type in a name and select “Done.” iTunes’ main window will now be displayed. Wait until you get an “Update Completed” message. You can now quit iTunes. Remove the USB or FireWire cable from your iPod. A few seconds after disconnection, your iPod will display “Language” options. Choose the language you want. You are done. If your iPod does not turn on, it might help to leave it unused for a period of about 24 hours. Try this procedure again. If it still doesn’t work, you’ll need to get professional help. If the iPod’s warranty is valid, you can contact Apple via their support page. If it isn’t, get it repaired from an expert.

 

For those into video gaming, being able to take advantage of the latest line of graphics cards means better frame rates, better image quality and, overall, an improved experience in every game. Upgrading a graphics card in a desktop is something anyone can do. All you have to do is buy the new card having checked whether your PC will run it, slot it in and install new drivers.

However, for those with laptop computers, upgrading the graphics card is quite another matter. You hear of people upgrading desktops all the time, with relatively few restrictions. By contrast, for laptops, it is hard to find the necessary parts and harder still to actually install them. Many laptop computers are simply not upgradeable in this respect, but you may be surprised to learn that a great deal of models actually are.

How Do I Know if My Laptop Graphics Card is Upgradable?

The first thing to check is what sort of graphics system your computer already has. If your laptop only has a basic integrated graphics solution as most lower end machines do, then there is no possibility of upgrading. This is because the graphics adapter is integrated into the motherboard of the machine and there is no slot in which to connect a new one. But if your laptop has an NVidia or Ati dedicated graphics adapter (be aware, they also have integrated ones!), your laptop might be upgradeable.

Secondly, the dedicated card needs to be of the MXM standard. MXM stands for Mobile PCI-Express Module and is the interconnect standard for many laptop graphics cards. MXM comes in various different types as well including the 1.3, 2.0, 2.1 and 3.0 specifications. To find out exactly which one your computer uses, you will need to search online for a list of laptop models and their graphics card types. You are not likely to get much help from your computer’s manufacturer regarding this.

Purchasing a Laptop Graphics Card

Of course manufacturers don’t want you to upgrade your existing laptop – they’d much rather prefer you buy a new one. This is because they would rather have you buy a new laptop altogether. MXM graphics cards are normally only sold to corporations. However, there are some sellers out there which do make a point of specializing in laptop cards. You may also be able to find them on the online auction sites. They cost quite a lot more than their desktop counterparts, but can be much cheaper than buying a new machine.

Installing a Laptop Graphics Card

Provided it is of a compatible MXM specification, installing a new card should not be too difficult at all. However, opening up your laptop will most definitely void your warranty – but chances are if you want to upgrade, your warranty is long expired anyway. If you are at all unsure about carrying out the upgrade yourself, you may want to leave it in the hands of a computer professional. Additionally, once you have physically installed the card, you will need to install the correct drivers for your hardware and operating system.

The upgrade isn’t as hard as it may sound, though, and in the end it’s worth it, since you’ll be able to play games better and get a better overall performance out of your old laptop, without having to spend a lot of money on a new one.