Results of The 6A05G Measurement and Discussion

22 Table . This shows actual forward voltage against forward current of A G at room temperature of ’C ; current and voltage were read after minute conduction.: a Current = A, b Current = A, c Current = A, d Current = A, _ e Current = A, f Current = A. The diode was let off the current for minutes before doing the next conduction. For this purpose the power supply was switched on and off while the junctions of the cables were kept untouched during the whole measurement process to ensure connection consistency. Test No. Continuous Forward Current A Continuous Forward Voltage V Test No. Continuous Forward Current A Continuous Forward Voltage V Test No. Continuous Forward Current A Continuous Forward Voltage V 1 1 0.90 1 2 0.9 1 3 1.01 2 1 0.91 2 2 0.97 2 3 1.02 3 1 0.91 3 2 0.97 3 3 1.02 4 1 0.91 4 2 0.97 4 3 1.02 1 0.91 2 0.97 3 1.02 1 0.91 2 0.97 3 1.02 7 1 0.91 7 2 0.97 7 3 1.02 8 1 0.91 8 2 0.97 8 3 1.02 9 1 0.91 9 2 0.98 9 3 1.03 10 1 0.92 10 2 0.98 10 3 1.03 Averaged 0.91 Averaged 0.97 Averaged 1.02 a b _ c Test No. Continuous Forward Current A Continuous Forward Voltage V Test No. Continuous Forward Current A Continuous Forward Voltage V Test No. Continuous Forward Current A Continuous Forward Voltage V 1 4 1.04 1 1.0 1 1.08 2 4 1.0 2 1.07 2 1.08 3 4 1.0 3 1.07 3 1.09 4 4 1.0 4 1.07 4 1.09 4 1.0 1.07 1.09 4 1.0 1.07 1.09 7 4 1.0 7 1.07 7 1.09 8 4 1.0 8 1.07 8 1.09 9 4 1.0 9 1.07 9 1.09 10 4 1.0 10 1.08 10 1.09 Averaged 1.0 Averaged 1.07 Averaged 1.09 d _ e f Table . Voltage predictions for the voltage adapter module that will be developed using the actual data of the Table . Actual voltage exists at the second cell of the battery bank usually slightly higher than V thus it is approached with . V. Load Current A Diodes Individual Drop Voltage V Predicted Total Drop Voltage V for Predicted Module Output Voltage If Input Voltage = 1 . V 4 Diodes Diodes Diodes 4 Diodes Diodes Diodes 1 0.91 3. 4 4. .4 12.9 12.0 11.14 2 0.97 3.88 4.8 .82 12.72 11.7 10.78 3 1.02 4.08 .10 .12 12. 2 11. 0 10.48 4 1.0 4.20 .2 .30 12.40 11.3 10.30 1.07 4.28 .3 .42 12.32 11.2 10.18 1.09 4.3 .4 . 4 12.24 11.1 10.0 227 Based on those data, voltage predictions for different options are made and shown by Table . A number of diodes are to be placed on board in series. Considering that the required output voltage is around V, the application of four diodes is then chosen in order to provide the closest value.

7. Result of The Module Development and Discussion

Taking into account the positive findings as discussed in Chapter , the A G diodes have been applied for the 8Vdc to Vdc voltage adapter module. Four diodes are placed in series. Through a development cycle the module was then finished and ready to test. Figure shows the stages of the development and the test. _ a _ b _ c _ d Figure . Some photographs taken in the development cycle and the testing: a after completion of PCB layout design, b after the etching, c after the completion of assembling, and d when the module was being tested. There are six diodes shown in the picture, two of them are actually being short‐circuited unused . A small modification was also made for the output terminals: USB terminal was provided for the phone charger along with protection resistors. Upon the completion of the module development, measurements were carried out in operation mode. The results of the measurement are shown in Table . t is found that module’s output voltage varies with the load current, as predicted. The voltage decreases when the load current increases. When the current ranges at to A the output voltage will range at .8 to . V. These values are lower than the prediction see Table. for the diode option , logically caused by existence of other drop voltages at the protection resistor and at the line on the PCB. Considering that the real requirement –that the devices on the eCar have enough tolerance for the operating voltage– this voltage adapter module would fit the need. 228 Table . The table shows modules output voltage at different loads: a = A, b = A,_ c = A, d = A, _ e = A, and f = A at room temperature of C. Four A G diodes were placed in series and the whole onboard circuit resistance was around . ohm. The values were read when the module was operating for minutes. The current supply to the module was cut for minutes before doing the next operation. The junctions of the cables were kept untouched during the whole measurement process to ensure physical consistency. Test No. Load Current A nput Voltage V Output Voltage V Test No. Load Current A nput Voltage V Output Voltage V 1 1 18.3 12.79 1 2 18.3 12.39 2 1 18.3 12.79 2 2 18.3 12.40 3 1 18.3 12.80 3 2 18.3 12.40 4 1 18.3 12.80 4 2 18.3 12.40 1 18.3 12.80 2 18.3 12.40 1 18.3 12.80 2 18.3 12.40 7 1 18.3 12.80 7 2 18.3 12.40 8 1 18.3 12.80 8 2 18.3 12.40 9 1 18.3 12.80 9 2 18.3 12.40 10 1 18.3 12.81 10 2 18.3 12.40 Averaged output voltage = 12.80 Averaged output voltage = 12.40 a b Test No. Load Current A nput Voltage V Output Voltage V Test No. Load Current A nput Voltage V Output Voltage V 1 3 18.3 12.01 1 4 18.3 11.81 2 3 18.3 12.01 2 4 18.3 11.82 3 3 18.3 12.02 3 4 18.3 11.82 4 3 18.3 12.02 4 4 18.3 11.82 3 18.3 12.02 4 18.3 11.82 3 18.3 12.02 4 18.3 11.82 7 3 18.3 12.02 7 4 18.3 11.82 8 3 18.3 12.02 8 4 18.3 11.82 9 3 18.3 12.02 9 4 18.3 11.82 10 3 18.3 12.02 10 4 18.3 11.82 Averaged output voltage = 12.02 Averaged output voltage = 11.82 _ c d Test No. Load Current A nput Voltage V Output Voltage V Test No. Load Current A nput Voltage V Output Voltage V 1 18.34 11. 9 1 18.34 11.41 2 18.34 11. 0 2 18.34 11.42 3 18.34 11. 0 3 18.34 11.42 4 18.34 11. 0 4 18.34 11.42 18.34 11. 0 18.34 11.42 18.34 11. 0 18.34 11.42 7 18.34 11. 0 7 18.34 11.42 8 18.34 11. 0 8 18.34 11.42 9 18.34 11. 0 9 18.34 11.42 10 18.34 11. 0 10 18.34 11.42 Averaged output voltage = 11. 0 Averaged output voltage = 11.42 _ e f The module has been installed onto the eCar successfully and the eCar is currently in normal operations as usual. Several machine maintenance activities have been also carried out and there has been no trouble with the module this far.