Circuits with IC555

December 17th, 2012

Some fun circuits with IC555, from my college days, compiled them all and put them under a GIT project. Hopefully I will be working on them in the months to come πŸ™‚

Till then, visit the below link and get the PDF containing 15 awesome circuits that can be built with IC555

7400 Contest !

December 2nd, 2012

The 7400 Contest had loads of awesome entries !

My entries Tic Tac Toe won a first place and Mathemagic won a third place !

Thanks a lot to dangerous prototypes for running the contest !

Now for the prizes !!!

Unfortunately, will be busy for the next two months πŸ™ – All experiments on hold !!!!!!

Edit : Here are some pictures!

1. Components form

2. Analog Discovery from Digilent!!




October 28th, 2012

First of all thanks to DangerousPrototypes! its because of you guys I worked on logic gates after college – else its usually the usual microelectronic stuff! πŸ™‚

This build is a simple ‘Tic Tac Toe’ game. I ended up using 30 Logic ICs ! πŸ™‚

Lets see the video first, then lets see the design



Design document:

<PDF alert> This document: Tic_Tac_Toe has all the block diagrams and circuit diagram used.



In the middle of the build

Tic Tac Toe

Tic Tac Toe


Do leave a comment if you have any queries!

PS:Β  The casing is ugly πŸ˜› Trying to build a good case for this project!

<Edit> Won a first place in the 7400 contest !


Random LED POV

October 25th, 2012


The main aim of this project was to generate a random (Somewhat ) LED blinking using Ic 555.

When browsing I came across an article to use Ic4026 to add some amount of randomness, But that was not enough . So an AND gate to β€˜and’ the outputs from two different astable multivirators (Ic 555 Circuits) and that was given as a clock source for the IC 4026. This made sure that the pattern would not be the same always.

One could change the patterns using the two potentiometers (trimmers).These potentiometers ensured that the frequency of the output has changed and thus the clock input to 4026 was altered.

Note : Only five output pins were selected from the set of outputs in a 4026 based on distinct blinking combination.

To make the whole setup spin , One small computer cooling fan was taken and a 9V battery was mounted(Glued) onto it ( In the center) . Now the circuit was mounted over the battery. Now when the fan rotated — The battery rotated along with it and so did the circuit — producing beautiful patterns of light.


Mathemagic – Mind Reader

October 25th, 2012

This is a simple application where in you think of a number from 1-99 in your mind and then the machine tells you what it is !

All you have to do is, think of a number and say if it is greyed out in the series of cards shown.

Before we step into any detail, Watch the video πŸ™‚



The concept behind this is a BCD to 7-Segment decoder(IC7447). The unit and tens place of the number are in BCD. For example let’s consider the number 24

Number 2 4 – This in BCD would be 0010 0100. Thus this number would be found in sheet3 and sheet6. When you press these corresponding switches, the number would come up in the 7-segment display.

The switches used here are momentary push switches. When the switches are pressed, we would need it to be giving a constant HIGH. For this we use D Flip Flop (IC4013).


Switch Configuration:

The flip flop is used to sense the switch input and it goes high permanently (until the reset button is pressed). For this we connect the β€˜data’ pin to VCC and the clock pin to the switch output. As the flip flop is positive edge triggered, this pin is pulled low with a resister and the switch is connected to VCC. When the switch is pressed, the pin is pulled up to VCC and this triggers the flip flop, thus the output pin β€˜Q’ goes HIGH.


IC7447 is used to drive the 7Segment. This circuit uses a common anode 7-Segment, the output of flip flops are directly fed to the BCD inputs of the 7segment driver.

Circuit Diagram:

<Very large PNG alert | Click to open in new window>


Let me know your comments πŸ™‚