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Power-Witts Switchmode Power Supply Design Software

Power supply design software

PowerStream specializes in the custom design and manufacture of state-of-the-art battery chargers, DC/DC Converters, and power supplies

Power-Witts Design Software Single seat $250

Short Description

Power-Witts is software developed for the specific purpose of designing and evaluating power supplies with the popular single-ended forward converter topology.

As the power supply designer you have the option of selecting a number of parameters based on the desired end result, for example input voltage, output voltage, power, number of DC outputs, line filter topology, rectifier style, switching and transformer schemes, feedback control schemes, etc. These sections are automatically designed for you as you control the desired specifications. Then the fast analysis tools allow you to simulate the circuit and get the same data that you would get on the test-bench.

Why use Power-Witts in the circuit design stage?

Power-Witts was designed by a world-class power supply designer who asked the question "what technical details do I have to solve over and over again that could be better solved in software?" All the options that he found useful are here.

Furthermore, the designer asked "What kind of data do I want the simulation to give me to aid me in testing and troubleshooting breadboards, brassboards, and prototypes?" The resulting software can plot all steady state wave shapes and transient currents/voltages for every circuit element. And it can do it much faster than spice models. And stability analysis is easy because it calculates voltage loop or current loop Bode plots and other frequency domain plots

In addition, as you go through the design process you have choices of what types of circuits to use for filtering, feedback control, switching, etc. This speeds up the process of design immensely because you can first pick a design for economy, then cut and paste different selections into the design as higher performance is needed. The simulation tools allow you to quickly evaluate a design and determine whether it is over or under designed.

What is the return on investment?

Design costs are the most expensive costs a business faces not only because of direct costs but also lost opportunity costs because the design is not yet on the market. This inexpensive software not only takes many days off the design time, but allows design variations to be tried quickly and accurately. So you get a more cost-effective design more quickly.

Hardware testing time is more effective because you can compare measured results with simulations without having to worry about the suitability of the model for switchmode applications.

Power supply engineers tend to stick with circuits that they have experience with because of the high schedule risk associated with trying something new. Power-Witts is an educational tool that allows you to try the most useful alternatives for the various parts of the circuit, building on the experience of the world's best power supply designers.
It would be an understatement to say that this software will more than pay for itself (and the time it takes to become proficient in its use) the first time it is used. Think of how much time it would save in the first design review when you can demonstrate that multiple approaches have been considered, and show why you have selected the best design.


  • High Precision - more precise than "behavioral" SPICE models because it knows the eccentricities of switching power supplies
  • High Speed - much faster than a SPICE based real time model
  • Simple Standard Windows User Interface
  • Up to 4 power supply outputs with or without output choke magnetic coupling
  • All of the popular control modes available
  • Wide variety of input and output filter types, ranging from simple to complex
  • Wide variety of primary switch section topologies
  • User specified core saturation characteristics
  • Plot all steady state wave shapes and transient currents/voltages for every circuit element
  • Make voltage loop or current loop Bode plots and other frequency domain plots
  • Synchronous/Non-synchronous rectifiers
  • Fast and easy circuit creation with an easy to use Windows interface
  • Intelligent circuit error checking and validation functions and much more
  • Higher Frequency Domain Accuracy -- Frequency domain plots use injected sine waves in the time domain simulator to generate gain and phase data rather than much less accurate average models.

Screen Shots

Here is the block diagram of a 4 output AC off-line power supply. Each of these blocks can be modified or replaced with an alternate circuit separately to optimize your design by simply clicking on the box.
block diagram of a power supply

Here is a set of plots to evaluate loop stability
loop stability analysis plots

And here are plots of transient and steady-state operation
output plots

System Requirements

  • Microsoft Windows (95/98 or later), Windows NT (version 3.51 or later), or Windows XP
  • Hardware requirements: IBM compatible, Will not work on NEC (Japanese) machines regardless of operating system.
  • Processor: 486 (Pentium class, 100 MHz, or better is recommended)
  • Disk space required: 10 Megabytes
  • Memory (RAM): 8 megabytes, minimum (32 or more megabytes, recommended)
  • Screen resolution: 1024x768 or higher
  • Small fonts recommended
  • Mouse: 2 buttons, minimum
  • Free support from the author, a world class power supply designer
  • This product is not returnable, warranty is limited to replacement of the media

Download Demo Version

Download this file into an empty folder: witts-install.exe
Open the file to unzip the installation files
Run "Setup.exe" to install the demo program
To start the program open the executable file which is PWDsef.exe


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Power supply design software for design engineers

PowerStream Technology
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