Convertor vs Transformer: Save yourself from burning your valuble equipment

Most of you might be aware that there are generally two voltage levels followed by different countries. For e.g. 220v standard is followed by countries like India, UK etc. while 110v standard is followed by countries like US. The following article is relevant to you if you have bought electronic/electrical stuff from a country which follows one standard, but want to use it in a country with other standard. And more likely you will be reading this article if you had already bought an item and burnt it by not knowing that you should use a converter or transformer to make it work properly. It may also be the case that you used a converter or transformer but still burnt your device. Don't be ashamed, we both belong to the same community and there are many others.

Before telling if you should use a transformer or a converter, let me tell you that your device may work without any converter. Recent gadgets which are typically carried across the globe by the travellers are compatible with full range of voltage from 100v to 240v. They include mobiles, cameras, laptops, electric razors etc. But check the input voltage rating nonetheless. It should be printed something like "Input: 100-240v". The output voltage rating does not matter.

Now coming to the main point...You should be careful in choosing a converter or a transformer so that your device does not get fried. Most of you might be knowing from your electrical class that you will need a step-up transformer to increase the voltage and a step-down transformer to decrease the voltage. The output voltage of such a transformer should be compatible with the input voltage of your device. Having said that, you should know that there is a different type of devices called "converters" which also does the job of increasing/decreasing the voltage. "converter" is a loose word. They are more accurately called solid-state converters. They are also called SMPS converters. As opposed to the coil mechanism in transformers, converters use electronic circuits to change the voltage levels. The difference in the operation of transformers/converters may be suitable or not suitable for the device that you are using. A quick way to distinguish is that transformers are generally bulky and heavy, whereas solid-state converts are small and lightweight.

If I can to go into a little bit of technical details here, a transformer-based converter converts the voltage by elongating the sine wave of the AC current but still preserving the sine wave formation. On the other hand a solid-state based converts just chops off the sine wave to reduce the voltage, and hence the output current do not follow a sine wave formation. This kind of current is not compatible with all types of devices. But the pure sine wave form of current is compatible with most of the devices.

To summarize: The general rule of thumb is most of the electronic equipment (gaming consoles, DVD players, speakers, mobiles, etc) needs a transformer based converter. Whereas, electrical appliances like motor-based appliances, irons etc can work with solid-state converters. Transformer-based converters can be used for long operating hours whereas solid-state based converts are for short-term use (typically 1-2hrs). When in doubt, it is safer to use transformer-based converters. Also make sure that the wattage(W) rating is compatible. It is safer if the wattage of converter is atleast 25% more than wattage requirement of your device.



Pointers: link1, link2, link3

Apple Peel: Use ipod touch to make calls (GSM).

Please do not jump to think that you can make GSM calls by installing an application. That is not possible because the communication chip itself is not present on ipod touch. This is hardware + software solution. This solution is not like many other solutions which lets you make VoIP calls using ipod touch. This is a hardware accessory which you have to attach to your ipod touch, install an application, and then use for making GSM calls. There is a catch here that the iphone should be jailbroken for installing the application which is used for texting and making voice calls. Currently it supports only 2G.

As you will be adding new hardware, be ready to have a bulky iphone ;). Do not worry much, it will not look like an outgrowth or like an extra limb. The whole hardware is nicely packaged into a single unit with an extra battery, communication chip and a sim card holder. The product is still at a prototype stage. But the cost looks very promising at $57. Best part, no carrier lock!

source: link

Android on iphone

You like both android and iphone and want both ?
Or are you irritated like me because of stupid restrictions put by apple ? 
Or you just want to try something cool ?

There is a way to install android 2.2 on iphone. The best part is that it becomes dual boot supporting both iphone firmware and android. Iphone 2G, &3G are supported. It seems 3GS is not supported. There are some sites with paid software which claims that they support 3GS, but I am skeptical. I would not go for the paid sites. First the iphone needs to be jailbroken. There are many tutorial out there on the web. Here are few links. link1, link2, link3.

There is a simple automated process by the iphondroid software. This is supposed to be the simplest of all. There is an updated version of this software just yesterday (1st sept 2010) and it is a coveted as single click installation. But as far as I see, there is not windows version of the latest tool.


I am itching to try this. Will update you with my experiment.

Update (3-sept): r13h is the latest version of this tool. But unfortunately the windows version (r13g) does not support 2G. The website mentions that 2G version will be supported in next release. It is not clear to me if there is a windows version of r13h which supports 2G or not because when I try to download the 2G version from main page, it gives me r13f. I still searching where to find windows version of r13h.

Update (6-sept): It seems that there is some problem with the NOR backup utility which protects against bricking the iphone. The release of latest (r13h) windows version for 2G is postponed. I think its worth waiting for the protection.

Update (8-sept): There is going to be a new release (r13i) for 2G this sunday.

Update (13-sept): The new version(r13j) for windows is released. Here is the link. I am going to try soon and will update you with my experience.

Update (14-sept): After many bug fixing finally the r13m version seems to work. I am successful in installing android on my iphone. Though its not fully functional enjoying running android on iphone.See some of my pics.

Put your wii remote to a greater use.

The following is a nice TED talk which demonstrates an wii remote hacking idea which extends the functionality beyond gaming. The speaker developed a freely downloadable software (his website) which uses the infrared sensing capabilities of the wii. In the talk he demonstrates few applications of the basic idea. He shows a infrared pen which uses the screen projection as white board. In another application, with two infrared devices, he creates two touch points which can be used as a multi-touch interface. But the best part is that the infrared device when attached to the head can be used as a head tracking device. The 3D projection keeps changing according to the position of the viewer head.

Milo and Kate : AI Game for the Xbox with kinect

The following video of a TED talk is about a game developed for Microsoft Xbox with Kinect controller. The characters in the game are AI characters. The player has to interact with the character by playing, talking etc with the characters. At the end of the game, the developers say that, no two characters will be the same. Very interesting. This is nice mixture of both AI & Kinect controller.

In the video that author says that people did not believe when there was a video release of the game. I agree that it is really hard to believe. He gives a live demo of it in the TED talk.

Beware of goldrain (goldra1n) scam that claims to unlock iphone4

There has be some articles (this, this) floating on the net that a tool named "goldra1n" can jailbreak and unlock any version of the iphone including the latest iphone 4. First of all, its a paid application. This is the first indicator that this is a scam as the tools developed by the elite iphone hacker groups (like iphone-dev team) are for free.

The goldrain tools is being marketed by a site named www.unlockiphoneus.com. When I last visited this site, it shows that it is suspended. But a new site "http://www.unlock-iphone.us/" popped up in that place. Beware of both these sites and do not get fooled. See the complaints on the site and discussions/updated articles(this, this) damning the tool.

How to find bootrom version of iphone 3GS (new bootrom or old bootrom)

When the hackers released the pwnage(v4.0/4.0.1) jailbreak tool for iOS4, it is mentioned that the 3GS phones with the latest bootrom (iBoot-359.3.2) cannot be jailbroken. Only the old bootroom (iBoot-359.3) can be unlocked for now. So, now the big question is how to find which bootrom does your 3GS phone have.

The iphone week number will help as a thumb rule to find if your 3GS iphone is having old or new bootrom. The 4th and 5th digits of the serial number will tell the week number of the phone. If your iphone week number is <40, then you will definitely have old bootrom. If the week number is >45 then you will definitely have new bootrom. In between, we cannot say for sure.

The sure shot method to determine the bootrom is to use some tool like 'usbview' after putting the iphone in DFU mode (Connect your iPhone to iTunes, turn off, click power+home button for 10 seconds, leave POWER button after 10 seconds, holding HOME button). After putting the phone in DFU you can follow one of the following methods.

method-1
- put the phone in DFU mode
- run the application usbview
- check "config descriptors" and refresh
- in the left panel, click Apple USB device
- in the right panel, find an entry which reads iBoot 359.x.x

method-2
- put the phone in DFU mode
- In windows, got to Start > Control Panel > System > Hardware > Device Manager
- Find "Universal Serial Bus (USB) Controller" and go to Apple Mobile Device USB Driver.
- Right click and choose properties and go to details
- Select device instance path
- The end of the info string will tell the bootrom version

method-3
See this link to find one more method using forecast(f0recast) tool. This tool will give the final summary if your 3GS phone can be jailbreakable, unlockable. Note that this tool is not yet updated to give suggestions for iOS4. It can accurately tell if your 3GS phone is jailbreakable, unlockable only till 3.1.3 firmware.