I
Ir. Hj. Othman bin Hj. Ah
Guest
http://www.brorson.com/gEDA/SPICE/x496.html
I was evaluating a few free and demo SPICE programs.
I'm surprised that my port of SPICE 2G6 could be the most reliable
Electric Simulator for large circuits. I did the port in 1990.
I am surprised that many textbooks don't emphasise SPICE simulations
in analysing circuits. I abandoned books that don't touch on this
program.
I believe it is vital for students who are exposed to electric
circuits to learn how to handle and program SPICE. It is no longer
necessary to calculate manually. You may know the priciples, but if
you don't know how to calculate reliably how complex circuits behave,
it is pointless to employers.
I shall choose ORCAD Lite for most of my important simulations. It may
be limited to a few components but it is sufficient for the course
that I'm teaching. PSPICE is reasonably close to SPICE.
I'm surprised the LTSPICE is not compatible. I tried the simplest
SPICE circuit, but it didn't even recognise the .AC command.
Tina from TI is also good but it insists on having an IC first.
As a backup, TopSpice is a good choice. It may limit the number of
components but it is small and run on PCs with Windows XP.
http://penzar.com/topspice/topspice.htm
I choose these programs based on their acceptance of standard SPICE
source codes, that are called netlists by these CAD programs.
For schematics, ORCAD is the best but too complicated. I had used them
for design up to PCB layout but not its simulation functions. At that
time, it was not convenient to program PSPICE for digital simulation.
Despite the increase in speed of PCs, I still believe that digital
simulations are based done by programs that are specialised for
digital. I shall be evaluating VHDL compilers for a logic design
course.
Another advantage of working with SPICE is the large number of example
circuits that SPICE can accept. Even commercial CAD programs have
options to output into SPICE standard netlists that can be fed to
SPICE programs.
I notice that the current developments are in integrating schematic
capture to simulation and plotting.
The trouble is there are too many bugs. I had to refer to the
traditional text output in order to get some information out of the
simulations.
LTSPICE somehow filter these outputs making it less informative.
Topspice gives out all these intermediate files.
Another advantage is the large amount of documentations of SPICE and
its derivatives. I just got a large manual of all the dialects of
SPICE.
If you want to simulate a large number of components reliably, you
may turn to my old dspice from simtel archives. It should be able to
run on Windows XP on the command prompt either command.com or cmd.
the output will be in text format so you'll need to adapt them to a
good plotter, such as PROBE from PSPICE.
After more than 15 years, the lack of reliable unlimitedly free SPICE
simulators and its associated support programs is not encouraging.
Worse, educators still don't want to expose students to SPICE,
especially in Malaysia.
Even in US, most textbooks ignore SPICE.
It is as though, educators teach students how to count while ignoring
completely calculators or tables.
If we want to concentrate on priciples, the most important is just
understanding Kirchoff's laws.
All other techniques are just ways of analying manually which should
be obsolete.
I was evaluating a few free and demo SPICE programs.
I'm surprised that my port of SPICE 2G6 could be the most reliable
Electric Simulator for large circuits. I did the port in 1990.
I am surprised that many textbooks don't emphasise SPICE simulations
in analysing circuits. I abandoned books that don't touch on this
program.
I believe it is vital for students who are exposed to electric
circuits to learn how to handle and program SPICE. It is no longer
necessary to calculate manually. You may know the priciples, but if
you don't know how to calculate reliably how complex circuits behave,
it is pointless to employers.
I shall choose ORCAD Lite for most of my important simulations. It may
be limited to a few components but it is sufficient for the course
that I'm teaching. PSPICE is reasonably close to SPICE.
I'm surprised the LTSPICE is not compatible. I tried the simplest
SPICE circuit, but it didn't even recognise the .AC command.
Tina from TI is also good but it insists on having an IC first.
As a backup, TopSpice is a good choice. It may limit the number of
components but it is small and run on PCs with Windows XP.
http://penzar.com/topspice/topspice.htm
I choose these programs based on their acceptance of standard SPICE
source codes, that are called netlists by these CAD programs.
For schematics, ORCAD is the best but too complicated. I had used them
for design up to PCB layout but not its simulation functions. At that
time, it was not convenient to program PSPICE for digital simulation.
Despite the increase in speed of PCs, I still believe that digital
simulations are based done by programs that are specialised for
digital. I shall be evaluating VHDL compilers for a logic design
course.
Another advantage of working with SPICE is the large number of example
circuits that SPICE can accept. Even commercial CAD programs have
options to output into SPICE standard netlists that can be fed to
SPICE programs.
I notice that the current developments are in integrating schematic
capture to simulation and plotting.
The trouble is there are too many bugs. I had to refer to the
traditional text output in order to get some information out of the
simulations.
LTSPICE somehow filter these outputs making it less informative.
Topspice gives out all these intermediate files.
Another advantage is the large amount of documentations of SPICE and
its derivatives. I just got a large manual of all the dialects of
SPICE.
If you want to simulate a large number of components reliably, you
may turn to my old dspice from simtel archives. It should be able to
run on Windows XP on the command prompt either command.com or cmd.
the output will be in text format so you'll need to adapt them to a
good plotter, such as PROBE from PSPICE.
After more than 15 years, the lack of reliable unlimitedly free SPICE
simulators and its associated support programs is not encouraging.
Worse, educators still don't want to expose students to SPICE,
especially in Malaysia.
Even in US, most textbooks ignore SPICE.
It is as though, educators teach students how to count while ignoring
completely calculators or tables.
If we want to concentrate on priciples, the most important is just
understanding Kirchoff's laws.
All other techniques are just ways of analying manually which should
be obsolete.
