![]() |
Circad is the perfect program to obtain a pcb starting with the electric scheme of an electronic circuit.
With these lessons you'll learn to use Circad at the best level. To do this you'll realize the circuit board
or PCB of the circuit beside. To draw the electric scheme is necessary to create a schematic file type, that have the .SCH extension. Circad can use many different files format, including AutoCad, text file, etcetera. Every type of file have diffent charateristics that depends by the extension!. In fact, Circad use a file in a specific mode that depends by the extension, for example linking library file. So, isn't possible to use custom extension, but it's necessary to use the reserved extensions types. |
.SCH Electric Scheme |
![]() |
.NET Components & Wiring |
![]() |
.PCB PCB Board Layout |
![]() |
.BOM Components List |
![]() Schematic Components |
![]() Error on the .SCH file |
![]() PCB Components |
Now we make the schematic file, that have the .SCH extension and that we'll
call TUTOR1. Select the File menu, then the New File option ... or . Insert the directory where you want to save the file. Circad will ask to select a template for the file. A template is a model for a circuit. We must create a .SCH type file, then select "Schematic Files" = Size A . The "A" format corresponds to an A4 sheet.
![]()
| The A4 format is the best you can select. If you are an engineer with a A2 plotter device... then select the other sheets formats. If your circuit is very complex remind that Circad is able to manage electronic schemes splitted in many schematics files. |
![]() |
Once you've select the template, Circad will display a save form, then select
the directory and the name of the file you want to create.
In the Circad Windows version you can use more than 8 caracters. Using the "Export filter" option menu you can select the file format, but if you don't need to reimport Circad '98 files in Circad 3.8, use the default option. Attention! Circad 3.52 and 3.8 DON'T recognize the Circad'98 file format, but Circad '98 is totally compatible (only to read) with these versions! |
To save the file, select the Esempio subdirectory, created with the special icon of the form, but you can select any directory you want.
All the instructions I've explained above are the same of + "Schematic Files = Size A" + C:\Programmi\Circad98\Esempio\Tutor1.SCH (if you have installed Circad in the Programmi\Circad98 directory) ... but we are only at the beginning of the course...
![]() |
After you've created the TUTOR1.SCH file you can customize or remove the information automatically added by Circad,
for example using the option to edit lines or texts, like
![]() ![]() ![]() |
The coordinates can be displayed only in inches. To evaluate the pcb dimensions of your board you can print the file
TARATURA.PCB (12k .zip) for Circad Dos/Win that
include many different reference and calibrating tools and a rubber converter centimeters/inches.
Conversion Table | Inches inchs | Centimeters cm | Mils of inch mils | Millimeters mm | ||
![]() | ![]() | ![]() | ![]() | |||
Inches inchs | ![]() | cm / 2.54 | mils / 1000 | mm / 25.4 | ||
Centimeters cm | ![]() | inchs * 2.54 | (mils / 1000) * 2.54 | mm / 10 ... | ||
Mils of inch mils | ![]() | inchs / 1000 | (cm / 2.54) / 1000 | (mm / 25.4) / 1000 | ||
Millimeters mm | ![]() | inchs * 25.4 | cm * 10 ... | (mils / 1000) * 25.4 |
Another important thing of Circad is about the layers use.
The layers are used to have every element you see on the
Circad draw area (text, lines, arcs, pads, etc.) into the right layer. For example, the lines used to make component shape must be assigned to the "symbol" layer, but the lines used to connect two components must assigned to
the layer "signal". The layers names depends by the file you are using. So, a schematic file like
TUTOR1.SCH will have the layer Signals, (where Circad stores all the electric wirings).
A .PCB file doesn't have this layer, but is will contains, for example, the Bottom Copper layer (Soldering Copper Side) and the Top Copper layer (Components Copper Side). With the option ![]() | ![]() |