<Back>

How do we design a small transformer?

Information about the 3 main steps to be taken in design - overview

The design of a small transformer consists of 3 steps:

1. Firstly you set up an input data file using the RALE Design Client program off-line. This input data file includes all relevant data for design of a small transformer.
2. Out of the Rale Design Client program you then connect to the RALE Design Server in Switzerland using the Citrix WinFrame Client communication program. For this purpose, the off-line created input data file is transferred to the RALE Design Server and the user can immediately step into the small transformer design process. On completion of design, the user can download the calculated results on his PC or print them out on-line and then break off the connection with the RALE Design Server.
3. You then load the downloaded, designed results within the Rale Design Client program on to your computer, read them or print them out.

Classification of the 3 main steps into 4 small steps

Phase 1 (Off-Line)

• Start your Rale Design Client software by means of the Rale Design Client icon in the WinFrame Client program group.
• Then select the icon Small transformers.
• Enter all relevant parameters for design, in the input data form.
• Save your input data file (optional).
• Click the menu option Calcualtion/Start or press F4.
• Rale Design Clients connects you with the Rale Design Server, transfers your input file and wait for your come back in the form Open Output File.

Phase 2 (on-line)

• Enter your log-on name and the password.
• Start your Rale Design Software by means of the Rale Design icon in the RALE program group.
• Select the icon Small Transformers.
• NotE that your input file is loaded into the input mask automatically
• Select an other input data file via the menu option Input/Load (optional) or press F2 to load your last input file, saved on the Rale Design Server.
• Start design via the menu option Run/Start or F4.
• Analyse the results, check the calculations in the test mode and print out the calculated results on-line (optional).
• Download the calculated results on your local PC.
• Quit your RALE Design Software.

Phase 3 (Off-Line)

• You are waiting for the results of the design in the form Open Output File. Load your downloaded output file. If you click Cancel your last downloaded output file will be loaded
• View or print the downloaded output data file.
• Quit your RALE Design Client

Concerning the mouse and the control buttons

You can use the mouse for everything.

The menu control can also be activated by means of the Alt key and the control letter for the menu option (after pressing the Alt key, it is normally visible in a different colour). Some important menu options can be activated by means of the F keys.

Here is a survey of all control keys:

RALE DESIGN Client Software (Off-Line)

After installation of the WinFrame Client communication software and the RALE Design Client software, you see the Rale Design Client program group on-screen.

Click on the Small Transformers bottom

After clicking on the Small Transformers bottom, the main menu for the RALE Design Client will appear on-screen.

RALE Design Client for small transformers

Input data file

(Numerical Characters =>Inputting), (Arrow, PgUp, PgDn, Mouse =>Move)

Your last input file will be loaded into the input mask. Here, you can incorporate the input data from an input data file and thus achieve drastic acceleration in the procedure for filling-in of the input mask.

(TAB=>Steps), (Click=>Marks), (Double click=>Selects)

In the installation of the Demo Design, a RALE library of input data files has also been installed, with the distinction between two groups:
The first group helps in the design of transformers which are designed in accordance with regulation IEC 61558 (VDE 0551), paragraphs 14.1, 15.3.2 and 15.3.3.

Example: R1532A4.TK1 or R1533F.TK

Captions:

For all input data files, an ambient temperature of 40^oC has been used.
After loading of an input data file from this group, you now only have to enter the value for voltages and currents in the input mask.
The second group of input data files illustrates how it is possible to design certain specific transformers. All of these input data files are extensively discussed in the design examples.
The third group of input data files should be created by yourself in the course of time.

Input

Important note:
No design can be performed using the RALE Design Client program for small transformers.

Nonetheless it plays an important part:

• It gets you used to handling the system.
• You can set up your entries off-line, store them in an input data file and use them via Internet on-line during connection with the RALE Design Server.
• During an on-line design procedure, you can download all of the designed results and then look at them off-line in the RALE Demo program and print them out.

The input mask consists of 5 areas:

1. Menu bar.
   
   
   
2. Input form for primary data.
   
   
   
3. Input form for secondary data.
   
   
   
4. Input form for general technological parameters.
   
   
   
5. Status line
   
   

The 6 fields of the status line indicate, in sequence, the core family, the core, the iron quality family, iron quality, and the minimum and maximum values of the current input.
The input process for primary voltages and the secondary windings is concluded by means of the PgUp or PgDn keys

on-line Help

Key F1 plays an important part at this point, because each input field has a help text. Use ESC to quit on-line help.

(Mouse, PgDn, PgUp, Arrow =>Move), (ESC=>Exit)

The input fields which are marked * are values with a unit of quantity (V,A,Hz,...) or multiplication factors. The input fields with - are code values. These can be entered or selected via the Options menu.

(ESC=>Exit)

Wires and iron quality

The input fields for Wire type (not wire size) and Steel are a minor exception in this instance and can be selected in addition to manual input via the Material/Wires/Fe menu or selected by means of keys F11and F12.

(Alt-M and F or F11only =>Fe-Quality), (Alt-M and W or F12 only =>Wires)

(TAB=>Move), (Click=>Mark), (Double click=>Select)

(TAB=>Move), (Click=>Mark), (Double click=>Select)

Core and bobbin unit

Using the menu option of Material/Cores or key F9, you can select a core with a given coil or set up your own preferred combination.
The distinction is drawn between 4 different approaches for selection of the core and of the coil:

Automatic selection
(Selection = 0)
In this mode, you just know the core family for the core and the coil from which you have to choose. But you don’t know which core is suitable for your application.

• Enter a 0 in the Selection input field.
• The core name in the status line must be AUTO.
• Dont forget that you have yet to select, on-line, the core family from which the computer program has to find a core suitable for your application.

Core and coils are selected off-line
(Selection = 1)
You wish to produce your application with a given core and a given coil from a given core family.

(Alt-M and C or just F9 =>Cores and Bobbins)

(TAB=>Move), (Click=>Mar), (Double click=>Select)

• Select the Material/Cores menu option or press key F9.
• Select a core family.
• Use the mouse to click on the core you prefer.
• Click on the OK button. The Selection input field has automatically acquired the value of 1.

After this procedure, you have no further on-line core selection work to do.

Core and coil are incorporated from a single input data file
(Selection = 2)
We have already selected an input data file before accessing the input mask, or we have loaded an input data file from the input mask via the Input/Open menu option. In this instance, we incorporated the core and coil stored in this input data file. The input field for Selection has a value of 2. Using this procedure, we have no further work to do with regard to core selection on-line.

(TAB=>Move), (Click=>Mark), (Double click=>Select)

The core and coil are manually entered off-line
(Selection = 3)
You wish to achieve your application with a given core and a given bobbin, but the core does not exist in any core family.

(Numerical =>Input), (TAB, Mouse =>Move)

(Numerical=>Input), (TAB, Mouse=>Move)

• Select the Material/Cores menu option or press key F9.
• Select a core family which could include your core.
• Use the mouse to click on a core which is similar to yours.
• Use the mouse to click on the Copy button and then Yes.
• Change the core, the bobbiand/orthe case.
• Click on the OK button. The Selection input field has automatically acquired the value of 3.

Under this procedure, we have no further work to do on-line with regard to core selection.

Saving the input data file

Your input is COMPLETE! It is recommended that you save your input data into an input file.

(Alt-I and S)

(TAB => Move), (Click => Mark), (Double click => Select)

• Select the Input/Save menu option
• Enter the name of your input data file (max.of 8 characters, and the extension .TK1 cannot be modified).
• Click on the OK button.

Connecting to the RALE Design Server (Off-Line)

Click the menu option Run/Start or press F4.Rale Design Clients connects you with the Rale Design Server, transfers your input file and waits for your come back in the form Open Output File.

This procedure is only available if you have installed on your PC a full automatiaclly connection to your provider and to the Rale Design server via the communication software WinFrame Client. Note that the Description of the entry for full automatically connection to Rale Design Srver has to be "Rale"

Note that you can connect to the Rale Design Server manual. Normally this procedure looks like this:

• Exit the Rale Design Client
• Connect to your service provider via Internet Dialer (Winsock,...).
• Minimize the Dialer screen.
• Run WinFrame Client
• Click twice on the name of the connection to the Rale Design Server.

Login (on-line)

Important note:
At any time and at any place in the RALE Design Software, you can interrupt the connection by means of the Shift-F3 key combination and quit the RALE Design Server.

After a successful connection, the following picture will appear on screen:

(TAB, Click=>Move)

• Enter your Login name.
• Click on the Password input field and enter your Password.
• Complete your entries with the {Enter} key, or use the mouse to click on the OK button.

If you register your login name and your password in the WinFrame Client software you will be not prompted to enter them on-line.
The main distributor of the Rale Design Server will then appear on screen.

RALE Design Software (on-line)

(TAB=>Moved), (Click=>Marked), (Double click = Activated)

Click twice on the Small Transformers icon or press the Enter key.
You are now in the main menu of the RALE Design Software. As you will notice, it looks exactly like the RALE demo software menu. The only difference between the RALE demo software and the RALE Design Software is the fact that the RALE Design Client software cannot design anything.

RALE Design Programm for small transformers (on-line)

Click on the icon /Small Transformers or pressEnter.

This is followed by the input mask on screen with your input data.

(Numerical keys =>Input), (Arrows, PgUp, PgDn, Mouse=>Movement)

The distinction is normally drawn between two approaches, in this phase:

• Where you have saved your choice of core and bobbin in your input data file off-line with the RALE Demo program.
  In this case, you see the name of the selected core on the status line. In the first position of the status line, where the core family name is normally found, there is only stated the core type (EI, UI, 3UI, SE, SU, 3SU, ETD,...).

• Where you have not selected any core off-line in your input data file.
  In the second position of the status line, the core name is given: AUTO. The name of the core family (Standard DEIS1.WSR) from which a suitable core has automatically been searched, is located in the first position of the status line. Normally, a core family has yet to be determined in this mode (Selection = 0). You access your core family selection via the Material/Cores menu option.

(TAB=>Move), (Click=>Mark), (Double click=>Select)

Design

Design is started via the Run/Start menu option or with key F4.

(Alt-R and S or just F4)

If you have not already selected a core, the program starts automatic search in accordance with one of your requirements from the core size as per your inputting, from the selected core data file.

The program starts searching at the first core of the core family and passes through to the last core in the family in sequence. You are invited to approve the first core which is adequately large for your application.

This is followed by the design operation. Note that there are 2 criteria of the optimizing: dT => temperature rise or dU => Regulation

Data page for winding
After the design procedure, a summary of the main results will appear on-screen.

(Mouse, control bar, Arrows, PgUp, PgDn=>Move)

The continuation of the above screen illustrates the extensive display of the design results. Each designed value is allocated with an appropriate explanatory text.

If you should need further information, please locate the cursor on the size value and press key F1. This activates on-line help.

(Mouse, PgDn, PgUp, Arrows=>Move), (ESC=>Exit)

Press Key "2" to jamp to this screen

Press Key "3" to jamp to this screen

Press key "4" to jump to this screen.

Press key "5" to jump to this screen.

Press key "6" to jump to this screen.

Press key "7" to jump to this screen.

Press key "8" to jump to this screen.

Press key "9" to jump to this screen.

If you are not satisfied with the results of design, you can :

• Return to the input form via the Input/Current menu option or by means of key F2, and reconfigure the input data on-line
• Or pass to the test mode via the Input/Test menu option or with key F5.

Activate the Input/Test menu option or press key F5.

Test mode

(Alt-I and T or F5 only)

In the test mode you can test a designed transformer and manually change its parameters.

(Numerical =>Input), (TAB, Arrows, PgUp, PgDn, Mouse=>Moved)

The input fields with the white background can be modified. For instance, if you want to change the wire size you have to move the cursor to the wire number:

Click the menu option Material/Wires or press F12 to open the list with the wires.

This the current wire size

Select the wire size which you want and pres Alt-O or click OK

Re-design in the test mode is activated via the Run/Test menu option or by means of key F6.

(Alt-R and Tor F6 only)

Here is the result after the re-design.

On-line help in test mode

In order to get on-line help in the test mode place the cursor where you need help and press F1

.

On-line printing

On-line printing is performed via the Output/Print menu option or by means of key F8. After activation of the print process, the data, totalling approx 16kB, is transferred to your PC. In the event that your printer has a buffer, this transmission will last for approx 10-20 seconds. If there is no buffer, then printing may take slightly longer. For that reason, you should save the results of design on your PC and only then load them off-line in the RALE Demo program for small transformers, and print out. The procedure for saving of the designed data looks like this:

Saving of results of design

Saving of the designed data which you can print out off-line on the data page for the winding, is activated via the Output/Save menu option.

(Alt-A and S)

Enter a name for the output file in which the designed data is to be saved.

(TAB=>Move), (Click=>Mark), (Double click=>Select)

Transmission takes approx.10 to 20 seconds.

This completes your design.

Quitting your RALE Design Software for small transformers

Select the Input/exit menu option or press key Crtl-F12 and then click on the Yes button.

Quitting the RALE Design Server

Click the log-off icon twice in order to interrupt your connection and quit the RALE Design Server.

Return to RALE Design Client

The Rale Design Client is waiting for the results of your design in the form Open Output File. After the results of your design have been transferred in the form of an output data file on your PC, you can look at them, analyse them and print them out using the RALE Design Client off-line.

If you press Alt-C or click Cancel your last designed results will be loaded automatically.

(TAB=>Move), (Click=>Mark), (Double click=>Select)

Printing is performed via the Output/Print menu option or by key F8.

(Alt-A and D or just F8)

If you need more information concerning the designed parameters, then locate the cursor on the design value and press key F1.

Quitting the Rale Design Client for small transformers

Select the input/end menu option or press key Ctrl-F12, and then click on the Yes button.

Important note:

In this context, we have just discussed the procedure for design of the small transformer. There is extensive coverage of the technical aspect of design, within the design examples.

<Back>