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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 color). Some important menu options can be activated by means of the F keys.

Here is a survey of all control keys:

F1 On-line help
F2 It loads your last input file into the input mask in which all of the input data and the results of design are stored
F3 Loads the default input, without any results of the design
F4 Starts design from the input data form
F5 Activates the test mode. This button cannot be pressed until after completion of design
F6 Designs in the test mode
F7 Indicates the loaded or calculated output data
F8 Prints out the loaded or calculated output data
F9 Activates the choice of core family and core with bobbin, and starts manual inputting of core, bobbin and casing
F11 Activates the choice of steel quality
F12 Activates the choice of wire family and wire
Ctrl-F1 Activates help for on-line help
Ctrl-Z Reverses the last input
Ctrl-X Stores all input data from a secondary into the internal memory. The cursor should be located in an input field of the secondary to be copied
Ctrl-C Overwrites the input data of a secondary with the input data from the internal memory in which the cursor is located
Ctrl-V Joins the input data from a secondary with the input data from the internal memory in which the cursor is located. The input data of the 8th secondary will consequently be lost
Ctrl-D Deletes the selected secondary winding
Ctrl-L View inductance vs. peak current
Ctrl-B View induction vs. peak current
PgDn/PgUp Completes the input for primary voltages or secondary windings. Steps between the Primary, Secondary and Mask input groups
Arrows Steps between the input fields in the input form and in the test mode
TAB Steps between the input fields

Run Rale Design Software for small chokes

After installation of the Rale Design Software, you see the Rale program group on-screen.

How do we design a small choke?

After clicking on the Small Chokes bottom, the main menu for the Small Chokes Program will appear on-screen.

Click on the icon /Small Chokes or press Enter.

How do we design a small choke?

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

Input mask

How do we design a small choke?

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

How do we design a small choke? How do we design a small choke?

Here are inputs for some typical chokes

Swinging Smoothing Choke

How do we design a small choke?

3 Phase Commutating Choke

How do we design a small choke?

One Phase Commutating Choke

How do we design a small choke?

3 Phase Motor Filter Choke

How do we design a small choke?

3 Phase LC-Filter Choke

How do we design a small choke?

Power Factor Correction Choke on the AC-side

How do we design a small choke?

Power Factor Correction Choke on the DC-side with Zero Curent Switching Mode

How do we design a small choke?

Drainage Choke

A typical rectifier circuit with the drainage choke Lac is shown in the next figure.

How do we design a small choke?

About currents and Lac

Through the drainage choke Lac flow dc current with the even and odd harmonics. The dc current and the even harmonics flow through the windings ab and bc in opposite direction and do not magnetize the drainage choke. The values of the even harmonics are limited by the Ldc choke. They are normally very small and can be neglected.

The odd harmonics are limited by the choke Lac and can be calculated as follow:

Uk = 1.41*Udc*(1-cos(kπ/3)/(k2-1)

Ik=Uk/(ω*Lac)

Where:

k = 3, 9, 15, …

Udc = DC output voltage

ω = 2*π*f

f = 50-60Hz

Uk and Ik = rms values

Normally the odd current harmonics higher then 3 can be neglected and the value of the inductance Lac is calculated as follow:

Lac = U3/I3/ω

where the value of the current I3 has to be set by designer. There are 2 conditions that have to be satisfied with this current:

  1. If the dc output current is smaller then 1.41*I3 then the rectifiers work in discontinuous current mode and the output dc voltage can not be controlled as in the continuous current mode
  2. If the primary windings are connected in stare then there are no 3d current harmonics in the primary windings. 33% of the current I3 flows only through each secondary winding. They are not compensated with the ampere-turns of the primary windings and the secondary produces the magnetic field outside of the core.

Normally the designer sets the I3 current as follow:

I3 = (0.01-0.05)*Id

About Input

Assume you want to design a drainage choke for the following operation conditions:

f= 50Hz

Udc = 24Vdc

Id = 1000Adc

I3 = 10Arms, 150Hz

and

U3 = 1.41 * 24 *2/8 = 8.46V rms, 150Hz

Lac = 8.46/10/(3*314) = 0.00089H = 0.89mHv

Note1:

The theoretical magnetic point of this choke would be: 0.89mH @ 14.1A. Normally there is always a difference between the DC current in the windings ab and bc because the rectifiers are never equal. It is recommended that you set the magnetic point at the point:

0.89mH @ 14.1 + 0.05*Id = 64.1A

The induction should be in linear part of the magnetizing curve: 1.3T

Note2:

Do NOT set the even harmonics of the DC current in the thermal current. If they can not be neglected increase the value of the DC current:

Idc new = (Idc^2+I2^2+I4^2+…)^0.5

Note3:

Use UI lamination with a cold rolled steel (M45 or M530) and the gap between the U and I part.

How do we design a small choke?

Input

The input mask consists of 5 areas:

  1. Menu bar.
  2. How do we design a small choke?
  3. Input form about choke.
  4. How do we design a small choke?
  5. Input form for harmonics of the thermal current.
  6. How do we design a small choke?
  7. Input form for general technological parameters.
  8. How do we design a small choke?
  9. Status line
  10. How do we design a small choke?

The 6 fields of the status line indicate, in sequence, the core family, the core, the steel, steel quality, and the minimum and maximum values of the current input. The input process for harmonics of the thermal current 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.

How do we design a small choke?

The input fields which are marked * are multiplication factors. The input fields with - are code values. These can be entered or selected via the Options menu.

How do we design a small choke?

Wires and steel

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 F11 and F12.

How do we design a small choke? How do we design a small choke? How do we design a small choke?

Core and bobbin unit

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

Automatic selection

(Selection = 0)

In this mode, you just know the core family for the core and the bobbin 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.

Core and bobbins are selected

(Selection = 1)

You wish to produce your choke with a given core and a given bobbin from a given core family.

How do we design a small choke? How do we design a small choke?
  • 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.

Core and bobbin 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 bobbin 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.

The core and bobbin are manually entered

(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.

How do we design a small choke? How do we design a small choke? How do we design a small choke?
  • 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 bobbin and/or the case.
  • Click Save in order to save the new created core and bobbin in the selected core family
  • 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.

How do we design a small choke? How do we design a small choke?
  • Select the Input/Save menu option
  • Enter the name of your input data file (extension .TK1 cannot be modified).
  • Click on the OK button.

Run designing

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

How do we design a small choke?

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.

How do we design a small choke?

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.

How do we design a small choke?

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

How do we design a small choke?

Data page for winding

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

How do we design a small choke?

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.

How do we design a small choke?

A summary of the main results will appear on 2 pages which you can view, print and save.

How do we design a small choke? How do we design a small choke? How do we design a small choke? How do we design a small choke?

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

How do we design a small choke?

In the test mode you can test a designed choke and manually change its parameters: turns, wire size, and material (Al-Cu), Steel, gap size and position, duty cycle, ambient temperature,...)

How do we design a small choke?

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:

How do we design a small choke?

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

How do we design a small choke?

This the current wire size

How do we design a small choke?

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

How do we design a small choke?

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

How do we design a small choke? How do we design a small choke?

Here is the result after the re-design.

How do we design a small choke?

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.

How do we design a small choke?

Printing

The printing is performed via the Output/Print menu option or by means of key F8. After activation of the print process, the data, total approx 12kB (2 pages), is printed on your printer. You can too save the results of design on your PC and load them and print out later. The procedure for printing of the designed data looks like this:

How do we design a small choke?

Saving of results of design

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

How do we design a small choke?

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

How do we design a small choke?

This completes your design.

Quitting your Rale Design Software for small chokes

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

Important note:

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