LTSpice is a good simulator ; It exports a netlist without packages .
FreePcb is a good Pcb designer , easy to use ; it can import a netlist with packages .
Lt-FreePcb builds a netlist with packages from the LTSpice netlist and it copies positions of components from
the schematic file ( *.asc) to the FreePcb project file ( *.fpc ) .
It's easy to start a pcb like this ...
This is the help file :
Code: Select all
I don't know a complete free software for simulation + Pcb .
LT-FreePcb is an interface between LtSpiceIV and FreePCB , that imports :
- a netlist exported by LtSpice ( PADS-PCB ) : example : xxx.net
- the LtSpice project ( xxx.asc ) with the components positionned like you want for the pcb ! this is the initial reference for positionning !
- the FreePcb project ( xxx.fpc ) with the components not positionned in FreePcb
- no packages in the netlist exported by LtSpice ; LT-FreePcb uses ' by default ' components + components by click on a list .
- these components are created by me , for LtSpice and for FreePcb ( new librairies to include where they are needed ) .
LT-FreePcb exports :
- a netlist for FreePcb ( Mod_xxx.net )
- the FreePcb project ( Mod_xxx.fpc ) updated with new components ( if you want that ) , and position of components : initial positions are taken in the LtSpice project ( xxx.asc ) , and you can adjust them visually with the mouse ( positionning x , y , zoom vertical and horizontal ).
LT-FreePcb cannot create a project for FreePcb from scratch ... ( I cannot , too much complicated ...) , so i have to begin a project in FreePcb with only a netlist , and save it for LT-FreePcb :
- in LtSpice :
- begin a project with the components positionned like i want for the pcb ; important , nothing is magic ...
- save the netlist (choice : PADS-PCB ) --> ( xxx.net ) and the project ( xxx.asc )
- in LT-FreePcb :
- Load the netlist exported by LtSpice ( xxx.net )
- choose components 'by default ' , click Final.net , choose the LT project ( xxx.asc ) in the file selector
--> change components , packages , or not ( also in case of click on ' Update ' , continue here )
- Save.net for FreePcb --> ( Mod_xxx.net )
- don't close LT-FreePcb
- in FreePcb :
- begin a project xxx.fpc
- import a ' Final ' netlist ( Mod_xxx.net )
- save the project without positionning the components
- in LT-FreePcb :
- Auto place . Ask for xxx.asc in a file selector . now , --> resizing with the mouse
- Save.fpc , choose the FreePcb project ( xxx.fpc ) in the file selector ; it will be updated to Mod_xxx.fpc
- in FreePcb :
- reload the project WITH the new name ( Mod_xxx.fpc ) : components are positionnned
- continue the job . There is no backannotation , but the xxx.asc file can be modified in LT .
- Click ' Update ' in LT-FreePcb .
- New values are loaded , ' Final ' net is displayed , continue to : ' --> change components , packages , or not '
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in ' packages-lt.txt ' :
Do not modify the lines : *Header , *------------- , ***** , *DEFAULT PACKAGES* and *END* ; they are used as marks .
In the lines : n-to92-ebc ,n-to92-bce , etc , suffixes 'ebc' , 'bce' ,'bec' , are used for netlist calculation . Do not modify 'ebc', 'bce' ,'bec'.
Datas are editable :
A / Packages before *DEFAULT PACKAGES* .(space between lines is only for clarity ,you can remove it).
You can add or remove packages in the good place. ( ex : bc 548,bc107 ... --> under n-to92-ebc)
B / Default packages after *DEFAULT PACKAGES* : ( But always 13 DEFAULT PACKAGES in the same order ).
3 for resistors : RC05 (5*2.54mm), RC06 (6*2.54mm), RC07 (7*2.54mm) . The 1st will be checked at start ! choose the order here
3 for axial capacitors : CK05 (5*2.54mm), CK06 (6*2.54mm), CK07 (7*2.54mm) . The 2nd will be checked ! . . . . . . . . . .
3 for radial capacitors : RAD-248 (1*2.54mm), RAD-394 (2*2.54mm), RAD-630 (3*2.54mm) . The 2nd will be checked !
3 for diodes : DO-7 (4*2.54mm),DO-15 (4*2.54mm) , DO-26 (6*2.54mm) . The 1st will be checked !
1 for inductor : IND-06 (6*2.54mm). ( 1 actually by default , 3 by manual choice in the clickable list ).
Packages for Transistors with standard names and packages ,or specific names (and footprints names in pcb software):
bc547,bc639, etc ...,n-to-92ebc or n-to-92bce ,n-to-126 bce ,... TO-220 bce , TO-3P bce . NPNs and PNPs .
you can use (click on it) generic packages : n-to-92ebc , n-to-92bce , etc , if footprints exist in Freepcb .
After simulations with LTspice , you can replace the transistors by these packages ,before saving the netlist ( just 2 clicks ) ; ( ex : bc547 becomes n-to-92ebc , a generic )
original packages in LT are made for Spice only , with specific pinouts ( always C = 1 , B = 2 , E = 3 ) , this is why i use new packages .
For resistors,capacitors,diodes and inductors , no changes , packages are correct . LtPcbNetlist will attribute a default package .
After that ,manual changes are possible by clicks .
But for inductors , the names are created by me : IND-05 , IND-06 , IND-08 .( 0x * 2.54mm) .
For analog ICs , actually only one specific package : DIP8 for ' TL071 ' . For a ' TL072 ' , maybe later ... ?
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Commands :
- Load.net : netlist from LtSpice ( xxx.net )
- Final.net : netlist for FreePcb . You have to select the LtSpice project ( xxx.asc ) , the Final netlist is displayed
- Auto place : global positionning , sizing pcb
- Update : reload the netlist , if the netlist has been modified in LtSpice , or if you want change ' by default ' components : choose a new ' by default ' component , and click ' Update '
- Save.net : save the netlist for FreePcb . The xxx.net is renamed Mod_xxx.net
- Save fpc : the project xxx.fpc (from FreePcb) is updated with the new positions and saved Mod_xxx.fpc
How to :
- change a component in the 'Final' tab : select a new component in the global list and click on the one to change in the 'Final' tab:
ex : Q1 BC547 @n-to2-ebc --> Q1 BC549C @n-to2-ebc
the package of a res , cap , ind , diode can be changed ; but for a transistor only if the footprint is the same : ebc , bce ...
because the net will not be modified .
Place all the files in the same directory . Good luck !
Download 2 : http://speedy.sh/cqU5T/Lt-FreePcb.zip with 2 jpg : main window and sizing + standard.bjt
MD5 : 2037DBCBA7E86B1B52C4382DDD7A043F Lt-FreePcb96.exe
179 Ko (183 808 octets)
No install , just an exe .