Create Electronic Circuits using Software

Many of you may wonder how to draw an electronic circuit or schematic on your PC.In this post I will demonstrate 2 excellent programs  to draw circuits.

1) ExpressPCB

http://www.expresspcb.com/expresspcbhtm/Download.htm

The ExpressPCBSetup program includes both ExpressSCH for drawing schematics and ExpressPCB for circuit board layout . Express PCB is a well known PCB manufacturing Company offering this  layout software  completely free, for business promotion.

2) EAGLE

EAGLE software is the best selling CAD tool in Europe.We are going to use only the limited free version , as our aim is to create circuits.

The name EAGLE is an acronym, which stands for Easily Applicable Graphical Layout Editor.

Download the Windows version (35Mb download) of Eagle software from

ftp://ftp.cadsoft.de/eagle/program/6.2/eagle-win-6.2.0.exe

New and improved EAGLE part libraries make your circuit creation a breeze.

Double click the downloaded  eagle-win-5.11.0.exe file to start the Setup

During setup select “Run as Freeware” option before clicking Finish.

After successful installation you can start the program to see the welcome screen :

Click File –> New –> Schematic  to start up drawing your circuit

For demo purpose I am going to show how to draw the following circuit in EAGLE

(circuit courtesy www.circuitstoday.com )

Note down the parts list in the circuit.The above one consists 3 transistors, 7 Resistors,3 electrolytic capacitors, 1 mic ,etc.,

To add these components click  Edit – > Add

ADD window pops up showing the vast list of component library from where you select the parts.

Scroll down the list to select Transistor or use the Search facility at the bottom to arrive at the required component.In the above circuit 3 nos. of BC548 transistors are used.As there is BC 547 in the list,select it and click ok. Later you can right click and change Value to Bc548 .

Now your cursor changes into a crosshair with the transistor symbol in the background.Clicking the mouse anywhere on the schematic window places the transistor symbol.Position according to the circuit and place all transistors by clicking the mouse.

After placing don’t forget to click the Red Stop button found on the top tool bar.This cancels further placing of  transistor symbol.

Again click Edit –> Add  . Now select Resistor .Under the list of resistors select the one that matches your requirement and click OK. Clicking the mouse on schematic window places the selected Resistor icon.After placing all the resistors click STOP red button to cancel further placements.

You can right click on any of the symbols placed to change the Name(T2,R1,..),Value (BC547,BC548,..), Rotate (place horizontal,vertical,..) and many more functions.

Before drawing wiring connections, place all components aligned according to the actual circuit.You can right click on any component ,select Move ,and place them anywhere you like.Always use STOP Red button on top to cancel further action.

Click  Draw –> Wire

A new tool bar appears below the main tool bar showing different options for Wire Bends, S bend, L bend, freehand wire bend,etc., Select any one of the Wire Bends or you can draw only straight lines by selecting Draw –> wire.

For e.g to place a wire from the Resistor R2 to base of Transistor Q1 ,

Click Draw –> Wire .Now place the cross wire cursor on the one end of Resistor R2 and click once the mouse.Dragging the mouse will draw a Green line.Drag it to base of Transistor T1 and click once.Click STOP Red button on top to complete this wiring.Repeat this process for all wiring. Note that while you move the cursor towards STOP button, the green line follows the cursor.Once you click the Stop button, the line between two clicks only remain.

After finishing all wiring you can save by clicking File –> Save .But the file is saved as .sch extension.

Instead you can File –>  Print –> Select Print to file (pdf) to save as a PDF file.

or File –> Export – > Image   and then provide a filename and browse to a location to store the file as .png,.tiff or .bmp image files.