Saturday 27 December 2014

My First Obstacle Avoiding Robot.....

It's a video taken from the ROBOTICS stall in "GHATECH-2011", an inter-college TECHNICAL FEST contacted in my college(Govt. Engg. College, Sreekrishnapuram,Palakkad).........

Thursday 20 September 2012


Build your-own LOW COST MultiPowersupply  ..

coming soon........................ 

 

                                      If you are interested in electronics, then you will definitely need a good power supply for your various works. In this section i would like to tell, how to make a simple lowcost multi powersupply that can capable of producing an output of 1.2v dc to 23v dc(step by step and fine turning) and -5v/0/+5v dc.
  




Saturday 21 July 2012

MAKE YOUR-OWN PCB(Printed Circuit Board) IN YOUR HOME... 

                       Now a days no electronic project can be completed without using a PCB . If you want to be a perfect circuit maker, you should able to design and create your-own PCBs for your various projects. So in this section I would like to share some basic knowledge that i have learn from my personal experience,I'm explaining those things using some small experimental examples, which are useful for the bigeners to create a small electronics workshop in their Home. If you are a bigener just go through the experimental example1 and then read the 5 step in details. I think that may be better to understand.
 Let us consider single side PCB first.

5 STEPS FOR GOOD PCB MAKING.

1.DESIGNING...

2.PRINTING...

3.ETCHING...

4.CUTTING & DRILLING...

5.TINNING & MASKING...

EXPERIMENTAL EXAMPLE-1 ( Single side PCB for a variable switching power supply. ) 


  • step1:-Mark the required size for the PCB on a copper clad and cut it using a small hacksaw ...



  • step2:- Wash it properly using a detergent and dry it with the help of a cotton cloth. Now we can draw the PCB diagram using a pencil ( This may help you to correct the mistakes while you drawing), then redraw the diagram using a permanent  marker as shown below....       

                

  • step3:-Now its time to remove the unwanted copper from the board. Take some ferric chloride power in a plastic container and mix it with water. (It is only required to dip the surface of the copper board properly,so right amount of water will avoid the wastage of ferric chloride). Use a little hot water will make the process become fast....
           

                    


  • step4:-Now we can dip the board in to the solution. Carefully tilt the container it will avoid the copper particle deposited above the board, it will also speedup the eching process..  

  • step5:-After a couple of minutes we can see our board is ready to wash, using a tweezer carefully take it out from the eaching solution and wash it with pure water... 
              

  • step6:-Cover the tracks with proper amount of lead to avoid resting of copper track and make the PCB more perfect to future soldering....
                 

  • step7:-Excess amount of lead can carefully remove by using a soldering wick and soldering iron tip as shown below...
                    


  • step8:-Now we can drill the holes for fitting components using a small hand drill..
                

  • step9:-Now we will obtain a cute PCB for our circuit.....
                
Note;- This example give a very basic idea about, what is actually happen in a PCB making process...
Now we can go through the 5 main steps for a good PCB making process, more deeply. 



1.DESIGNING..

         Designing make the first major step behind the Printed Circuit Board (PCB) making process.It can be said that, this is the key process for a PCB Fabrication. It bring compact size and shape to the circuit through proper arrangement of components and  effective utilization of the available space. For a complicated circuit, designing gives the ultimate freedom to the circuit maker to create their-own size and shape while keep in mind, the ultimate goal of a PCB designing is to use the minimum space without harming the components each other. This process not only reduce the cost of PCB fabrication but also give attractive shape and size for our projects. As a designer first we need a good designing tool, there are lot of PCB designing software's available today,for a bigener, i will recomented ''CIRCUIT WIZARD''(for windows) and KICAD(for linux, more powerfull than CIRCUIT WIZARD).They are simple and easy to understand. If you like to be with open source software's, you can use ''KICAD ,Eagle cad maker'', ''express PCB'' etc. Eagle cad PCB software have a very powerful component library than Circuit Wizard. For easy understanding for the bieners here i use Circuit wizard.
                             After installation of Circuit wizard go through the  Guided Tour(lecture videos in that software). It will give a good basic idea about that software and how to use it too. You can find lot of good video lectures from you-tube too. Now let us start with a very basic power supply circuit that can  provide an output voltage of -5v/0/+5v regulated DC.(This circuit is exactly used in the multi-power supply project)

  • Step1:-Circuit drawing and analysis.
                            First step of every PCB designing is to draw the circuit, one which we would like to make the Printed Circuit Board, clearly in the "circuit diagram sheet" in the software window(You can see 3 layer of sheets named as "Circuit Diagram","PCB Layout'',"Bill of Materials") as the one given below.

              after the drawing one can check the working of the circuit, here we are going to check the out put purity of our circuit diagram.
  1. Select an "AC voltage source" from the "Gallery"and connect it to the circuit diagram as shown below, then double click on the source,make it 9V/50KHz.
  2. Select the 'Current flow mode'(left side), then click the 'Play' button on the top. Now we can see the current flow.(Don't forget to connect proper ground)
                                           


 Now its time to analyse the circuit working. We can see the variation of current flow in the animation. Here -ve 5V indicated by blue colour, +ve 5V indicated by brown colour and ground by green.Click the graph button on the top bar, then a graph will appear in the bottom of your circuit diagram. Right click the graph and edit it for +10V Max and -10V Min.Then click the "Add prob" button on the top bar that allow us to plot the voltage variations of the output (here i use two prob's for -ve and +ve output). then Run the circuit diagram,but we can see our output is distorted, just increase the value of the AC voltage source from 9V to 15v by the step of 3V and check the out put.(Note that the input section of our circuit is a bridge rectifier,we can use a center taped transformer for circuit implementation).

    Therefor we can conclude that we can use a 230/9-0-9V transformer for better output.

Note:- You can change the components value and improve your circuit specifications..... 

  • Step2:-Convert to PCB.
                             
Circuit wizard give us the ultimate freedom for simple and complete autorouting in few simple steps(autorouting is a process to draw all the required connections lines automatically within the software).However i suggests that first you should go through autorouting and manually rearrange the components then redraw the tracks as you wish. Click the "convert to PCB" button then read the suggestions carefully and proceed it will give us an output like the figure below.

            

Then rearrange the components and make your own design as given below(Note:- Don't forget to crosscheck your PCB and make sure the tracks are suitable for your circuit). Each time you rearrange you will lost your track that can be manually redraw or use the auto-routing button. Finally you you will get your-own PCB design for your circuit just like the one given below.







                                                          


to be continued............................................ 

Sunday 8 July 2012

USBsap

BUILD YOUR OWN USBsap - USB programmer for Atmel AVR microcontrollers.

 COMMING SOON..........

            AVR microcontrollers are popular because of their Linux support and their softwares like AVRGCC and AVRDUDE.If you are interested to start learning microcontroller programming, AVR is a good option. It have a good software and hardware suppot all over the world. Simply we can use a printer cable (parellel port) as our programmer. Now a days it is really hard to find laptops with parallel port. So hear, first i would like to introduce HOW TO BUILD YOUR OWN USBasp - USB programmer for Atmel AVR microcontrollers.

 









Components required


  1. printer cable using parallel port..............1
  2. bread board............................................2
  3. atmega8(with ic base)............................1
  4. 12 Mhz crystal ......................................1
  5. 22pf capacitor  ......................................2
  6. 100uf capacitor .....................................1
  7. 0.1uf capacitor.......................................1
  8. LED (red and green) ............................2
  9. resistors,1k ohm....................................2
  10.               2.2k ohm.................................1
  11.               68 ohm....................................2
  12.               10k ohm..................................1
  13. 3.6v zener diode....................................2
  14. common printed board/PCB....................1(optional)
  15. Relimate connector(6pin) or FRC connector(10pin).........(your option)
  16. USB onboard male/USB cable from old leyboard............(your option)
  17. berg strips and connection wires


Software required


  1. Win AVR    (you can download it from http://sourceforge.net/projects/winavr/files/WinAVR/20100110/  )

Saturday 23 June 2012

Multiport mobile charger using few 1.5v cells..

coming soon........................