Thursday, February 4, 2016

Design electronics circuits online

I was searching for free online circuit design & simulators for some time. Could see some today. Just aggregating those sites here.

Still trying to figure out what is the best free.

[Update on 26Mar2018]

Free electronics simulators which can be used in browser

The sites are listed on ranking I have given based on my experiments.

For beginner, enthusiasts


For advaned users


List of other indexes

Thursday, August 21, 2014

Excel formula to show difference of time in proper format


There are 2 columns in my excel which tells 2 times say EndTime and StartTime. I have to show the difference between these 2 columns in next column.


If the EndTime is in column B and StartTime is in column A and want to show the difference in column C

Just use the cell formula =B1-A1 in the C1 cell apply the same formula to all the cells by simply dragging.

In the normal scenario we can see the difference in h:mm:ss format. But actually speaking we are not telling column C that the format should be h:mm:ss. This leaves an option in future that the difference may be shown as decimal number. So how to include the same in cell formula.

Use =TEXT(B1-A1,"h:mm:ss")

Thursday, April 24, 2014

Installing Win 8.1 in USB drive and advantages of Win 8.1


How to install Windows To Go in USB

I strongly suggest to try this using USB 3.0 external hard drives or Pen drives on your machine's USB 3.0 port. Otherwise it will become useless as the data transfer speed is very low

If we simply boot from USB drive and try to install Windows 8.1,it will end up in a message as follows.

You can’t install Windows on a USB flash drive from Setup. Error code: 0xc1900104

So what we can do. The solution is Windows to go.This will help us to setup the OS in the USB disk with in 3 major steps, if we already running Windows 7 OS and have the Win8.1 ISO obtained.

What we need

  • Windows 8.1 .iso image
  • GimageX
  • Machine which supports USB 3.0 & booting from USB 
  • USB 3.0 disk with at least 32 GB


  • Setup the primary partition in the USB disk .Make it active. Lets say it's drive letter is O:\
    • I don't think, I should explain how this can be done as its common already.
  • Apply file
    • Make sure the Win 8.1 ISO file is mounted using any disc management software such as MagicDisk.Lets say mounted drive letter is D:\
    • Download GIamgeX utility and apply/install the install.wim file present in Win 8.1 iso into USB.The path to install.wim will be d:\sources\Install.wim
      • This will take some time and copy required files into our USB drive including O:\Windows
  • Next install the boot manager.
    • O:\Windows\System32\bcdboot.exe O:\Windows /s O: (Here we are using the bcdboot utility of win 8 itself
      • If this is not working if you run from windows folder. Copy the bcdboot.exe from Windows 8 system folder to your Windows 7 desktop and try the same.
  • [Optional] Now reboot the machine. Have required changes in BIOS to boot from the USB disk. If its not booting Windows 8.1 and showing error message, follow the below step after logging into old Windows 7 which is installed in internal hard disk.
    • O:\Windows\System32\bootsect.exe /nt60 O: (This will correct the master boot code)
This is the way I tried. Of course there are many more ways. I was not able to complete my installation by looking at one single tutorial. That's why I thought of posting my experience. Some of those are listed below.

Thursday, December 13, 2012

DYI Magnetic knife holder

I saw magnetic knife holder in one of the English movie which tells the story related to a restaurant and it's kitchen. From then onward I was searching for a good magnetic holder.Not able to find it in stores located at Kochi. Then searched in Indian online shopping sites.I was able to find some but really costly. After that when I got a chance to visit US, I searched the same. Its cheaper comparing with Indian sites. But still costly.

So automatically the search extend to DIY sites. Hope you know what is DIY. Do It Yourself where people share their experience with creating things themselves which costs almost nothing. Got some tutorials there to setup magnetic knife holder but those needs more effort.So decided to explore our kitchen for anything which will help to setup the magnetic holder easily.

Luckily I found our windows which is just made of iron rods. It made the things easy I had to collect some magnets and stick into that window. Sharing some photos. Hope it may help others.

Thursday, November 15, 2012

*#0*# in Samsung Galaxy to test LCD

This code is used to test the LCD screen of mobile devices. It can mainly perform testing of following functionalities
  • Test pixels and screen by turning all pixels to Red / Green / Blue or White
  • Test vibration
  • Test dimming of pixels
  • Test Camera
  • Test sensors such as accelerometer,proximity, magnetic etc…
  • Touch testing
  • Sleep mode
  • Speaker (By playing ringtone)
  • Test keys
I have tested it in my Galaxy Y. Hope this is available in all Galaxy mobiles and almost all Android mobiles.

Thursday, October 25, 2012

My favorite online shopping sites in India

Most of the sites are offering products in all most all the categories. But below are my favorites for each category.

Important thing in online market is 'before confirming any deal check for discount coupons available for the sites'. Really you can save more.  Yesterday I got Rs500/- off on Rs1000 related to Dussehra from allschoolstuff
Getting coupons is simple.If you want to get coupons for eBay just google for eBay India coupons

There are some sites available to check the cheapest online price of products in single place. Use them if you don't have time to check all the shopping sites.

Seems the online shopping is really growing in India. Regardless the international giants enter into the Indian retail market or not, small retailers are going to face a tough competition from online. Hope I can add more sites based experience.

Thursday, October 11, 2012

How to find your processor architecture is x64 or IA64

Today we had a situation in office that a COM component for zip compression is not working in 64 bit server machines. It was working fine in desktop machines .Most of the desktops have 32 bit OS and some are 64bit. When we looked into the issue little deeper, we could see that there are different COM for different processors. In 32bit we need to register one com library file which is not same in 64bit machine. 64 bit file is suffixed with the '64' word. The 64 bit desktops are working fine then why the 64 bit servers are not working.

Little more google brought one more file for 64 bit machine which is nothing but the com lib file suffixed with IA64. Then the direction of work turned to find out the version of processor architecture of server machines. We opened the properties of 'Computer' from start menu,DxDiag etc...But no luck. Finally a google gives the name of the environmental variable "%PROCESSOR_ARCHITECTURE%". Yes it works.


Executing the above command in command prompt gives us the processor architecture of current machine. Still confusing what is x64 and IA64 ? Just google to get links like this or read wikipedia articles.

If you are interested more on environmental variables see this link.