Did you accidentally hook up your IC in the wrong way ? wanna find if it still works? well this is where the below circuit comes in handy , this is an astable multivibrator circuit , If your “Test” IC is alive then the led blinks in an alternate fashion.

Working:
” Astable mode ” means that that none of the generated states is stable , ie the out is a varying square wave , the width of the positive and negative pulse can be set by changing the values of R1 and R2 . When the IC is working , a square wave is produced , when the state is high , The LED2 glows and when the output goes low the LED1 glows.

Note :One can use a IC555 timer software for designing circuits .

Here is the video :

Well there are many reasons why you should do so ,Recently was “googling” about a classmate of mine and I found this

The above circuit will produce a police siren effect . Actually I found this circuit online long back(don’t remember the source) and made some changes .
Working :
Both the 555’s are wired to work in astable mode . The first IC555 produces low frequency square waves which is then given to the ” Control ” pin of the second IC, thus when the voltage at this pin we can vary the time electronically which in turn changes the frequency of the output . The output of the second IC555 is given to a capacitor , the capacitor turns the square wave to a triangular wave output (nearly triangular) , this when given to the speaker a “eaeee-uhnnnn” effect .
Notes:
You can change the out put sound (length and so) by changing the output capacitor, ie C3

Note :
The circuit was already available on the net (This is an edited version)

Here is a video

First of all ” An exceptional theme” ! The story has all from the Hills to Hitler! Filmed at the majestic Alps , This the finest musical - drama I have ever seen. The story centers around a family whose head is a retired “Austria” naval officer .He runs his home like a military camp after his wife passed away.Then comes in Maria as a governess - who changes every thing .She is a joyful,innocent,honest lady who spent her life in the abbey , She fills in music and joy in the barren lifes and house .Then after several short turns , Maria is married to The Captain Baron Von Trapp . Now comes the big twist , The Nazi takes control over Austria and forces the Captain to assume position in the navy .How captain manages out of Austria is the rest of the story .

Summary :
The good stuff:
Good movie to be watched!
very good musical delivery
I am 16 going on 17 is a very good song

The Bad stuff:
The reverend mother sings at very high pitch ! Do not keep your speakers at high volume!

We all use anti viruses because we are still on Windows , I use avast anti virus because it is neat , free and efficient . It has a good interface and to add it has a very good “sound ” alert , when it updates or detects a virus it gives you an alert using some audio . I was looking forward to customize it to my own voice or sound so here is the guide - The next time you have a virus or updates -make it sound the way you want it to.

To change the sound files:

Step 1: Locate The sound files you will find it mostly in the
C:\Program Files\Alwil Software\Avast4\ENGLISH\
the files are
1.vpsupd.wav for “Virus data base has been updated”
2.suspic.wav “potential infection was detected”
3.virfound.wav “Caution a virus has been detected”

Step 2: Now you can record your own voice or other voice in audacity save it in .wav format

Step 3: Now copy those files in the folder located in step 1.
Note : Remember to make a back up copy of those files which you replace
Here is a set of files which you can use