Designed and Prepared by: Emre Kilciolu

DC-DC Converter Test Program

The test program that I have designed is DC-DC Converter test program.

Figure 1 shows this converter. Its DC input range is 18-75 V and its nominal

value is 48 V. Whatever we give the input in this range, the output should be 3.3

V, 15 V, 5 V, 9 V, 12 V or 24 V with 1% according to the model of the

converter. There are six models according to the output voltage.

Figure 1 DC-DC Converter

Figure 2 shows these models parameters.

MODELS OUTPUT

VOLTAGE

OUTPUT MAX.

CURRENT

EFFICIENCY

TMR 6-4810WI 3.3 VDC 1500 mA >81%

TMR 6-4811WI 5 VDC 1200 mA >84%

TMR 6-4819WI 9 VDC 666 mA >85%

TMR 6-4812WI 12 VDC 500 mA >87%

TMR 6-4813WI 15 VDC 400 mA >87%

TMR 6-4815WI 24 VDC 250 mA >87%

Figure 2 Parameters According to the Model

Figure 3 shows the output specifications of the converters.

Figure 3 Output Specifications

My purpose is to design a test program about 4 parameters of converters:

load variation (0.5% max), input variation(0.2% max), efficiency (variable

according to the model) and voltage set accuracy (variable according to the

model). If the converter is appropriate for all of the parameters, the program

says the converter works properly. If not, the program says the converter does

not work properly.

The programs panel page is shown below in figure 4.

Figure 4 Panel View of the Program

The panel view contains the name of the technician who uses the program,

the registration number of him/her and the ambient temperature. Also, he or she

should choose the model of the converter from the list. After these are done, the

user clicks Start. After that, the program asks for minimum input voltage, max.

input voltage, nominal input voltage and serial number of the converter. Figure

5 shows these questions on the screen.

Figure 5 The Questions of Parameters

After these datas are all entered, the program starts to work and then, the

resulting page is seen. Figure 6 shows this resulting page. As seen, the page

contains the entered name, registration number, model, temperature, serial

number and the date and time when the program tests the converter. Also, the

resulting parameters are seen as both values and passed/not passed conditions. If

the converter passes all four parameters, the converter works properly. For the

converter TMR 6-4813WI in figure 6, the output should be 15 V with +-1%

tolerance, input variation should be 0.2% max, load variation should be 0.5%

max and the efficiency should be greater than 87%. As seen, the result is in this

range, so it passes this parameter. Also, it passes all other three parameters as

seen in figure 21. Therefore, it works properly.

Figure 6 The Resulting Page

Also, the program also writes the results on a notepad. Figure 7 shows this

notepad after the program finished the test.

Figure 7 The Results on Notepad

Now, let me show the detail of the program. This program took my one

and a half week to think and construct it. Firstly, in Main, the program is seen

like in figure 8.

Figure 8 Main Screen

The program starts and after the questions are asked, the system calls a

function called hesaplar in which the measurements and comparisons between

the practical values and theoretical values with their tolerances are done. In

addition, the right side of the main page is for setting the theoretical efficiency

limit, max output current and output voltage according to the chosen model type.

After that, under the function called hesaplar, the program is seen like in figure

9.

Figure 9 Function Called hesaplar

Firstly, the userobjects which are ykszhesaplar and yklhesaplar

are worked. The efficiency, its passed/not passed condition, the output voltages

for the entered input voltages are done in yklhesaplar like in figure 10.

Yklhesaplar occurs when the converter has a load with it. The voltage

accuracy for three different input voltages, the general voltage accuracy

passed/not passed condition, input variation and the output voltages for the

entered input voltages are done in ykszhesaplar like in figure 11.

Ykszhesaplar occurs when the converter does not have any load with it.

After that, the load variation is found in hesaplar and for all four parameters,

the practical values are compared with theoretical values with their tolerances. If

the practical values are in the range of tolerances, the converter passes for that

parameter. Note that in figure 11, the first picture is the first part and the second

picture is the remaining part of the UserObject ykszhesaplar.

Figure 10 UserObject Called yklhesaplar

Figure 11 UserObject Called ykszhesaplar