Frequently Asked Questions
- The performance of the applets is very poor on my computer. What can I do?
- Most applets do not work on my computer. Only a gray rectangle appears on the screen. How to solve the problem?
- Is there any company involved in the iPES project?
- Is it possible to use iPES for education in industrial companies?
- What are the differences between iPES and circuit simulators (like PSpice) in education?
- Will there be more translations?
- What is the simulation engine used inside the applets?
- How long does it typically take to produce one new applet?
- How often are there updates?
The performance of the applets is very poor on my computer. What can I do?
Basically there are two different kind of performance problems. Before trying to solve the problem you
should identify the kind of problem that dominates on your computer.
(1) There is a problem with the memory. In this case the Java applets "freeze"
after some time, suddenly work again, "freeze" again, and might finally crash. This occurs on
WinME/WinNT/Win2000 operating systems, especially on laptop computers.
Possible solutions: Use a web-browser different from Microsoft Internet Explorer to view iPES (for example, Netscape).
Download the Java plug-in from Sun (see link at the left-hand side) and use it instead of the Java that comes
pre-installed with the Microsoft Internet Explorer.
(2) The reaction due to a parameter change is slow. In that case the CPU
is too slow. We test all applets on a Pentium I / 266MHz / Win98 - computer.
This is the minimum requirement to get response times below 400ms for most applets.
If you work on Win95 or Win98 operating systems use Microsoft Internet Explorer (but be aware that this might
cause new problems as described above). Update your hardware with a faster CPU.
Give the process of your web-browser a higher priority (Task Manager -> Processes -> Set Priority -> ...).
Most applets do not work on my computer. Only a gray rectangle appears on the screen. How to solve the problem?
This is a problem with the older iPES-versions (date before August 2002). Just download the latest iPES-version
which should work fine.
Background: The applets in the older iPES-version communicated with each other inside the web-browser which
is not part of the Java specification but has been a feature of most web-browsers. With the Java2-PlugIn becoming
more popular (especially after Microsoft temporarily removed Java from its new operating system WinXP) this feature didn't
work as before resulting in gray rectangles instead of animated power electronics circuits. We changed all applets in the
way that this feature is not being used any longer.
Is there any company involved in the iPES project?
No. It is a project powered by the Power Electronic Systems Laboratory (PES) at the ETH Zurich.
Is it possible to use iPES for education in industrial companies?
Yes. iPES is free, for non-commercial use, including training lectures in companies.
iPES will be available also in future, simply because we want to support education in
power electronics and we want people to use it.
What are the differences between iPES and circuit simulators (like PSpice) in education?
Basically, while circuit simulation is done in addition to the practical exercises in the
laboratory for speeding up prototype development, iPES is used in addition to textbooks in the
theoretical part of the course and does speed up understanding of the theory of a circuit.
Will there be more translations?
Yes. We are very open for comments and ideas.
What is the simulation engine used inside the applets?
It is self-written in order to minimize the size of the files (applets) to be downloaded and to
optimize the simulation speed. This is necessary to make iPES available also to users with
slow modem-connections and low clock frequency computers.
How long does it typically take to produce one new applet?
Just a few days. But all work is based on a specially designed library which has been developed over
more than one year and which is improved continuously.
How often are there updates?
We continuously improve older applets of iPES and add new material. Minor changes and additions will be done every
2 or 3 weeks. The download-version will be updated every 5 or 6 months.