Desired Voltage | Buck Output Vin= 20 V | Buck Output Vin= 19 V | Buck Output Vin= 18 V | Buck Output Vin= 17 V | Buck Output Vin= 16 V | Buck Output Vin= 15 V | Buck Output Vin= 14 V | Buck Output Vin= 13 V | Buck Output Vin= 12 V |
12 V | 12.26 | 11.6 | 11 | 10.3 | 9.7 | 9.1 | 8.5 | 7.9 | 7.2 |
13 V | 13.51 | 12.8 | 12.1 | 11.4 | 10.7 | 10 | 9.4 | 8.7 | 3.9 |
14 V | 14.28 | 13.5 | 12.8 | 12 | 11.4 | 10.6 | 9.9 | 4.3 | Error |
15 V | 15.29 | 14.5 | 13.7 | 12.9 | 12.2 | 11.3 | Error | Error | Error |
16 V | 16.22 | 15.4 | 14.6 | 13.7 | 12.9 | Error | Error | Error | Error |
17 V | 17.24 | 16.3 | 15.5 | 14.6 | Error | Error | Error | Error | Error |
18 V | 18.24 | 17.3 | 16.4 | Error | Error | Error | Error | Error | Error |
19 V | 19.07 | 18.2 | Error | Error | Error | Error | Error | Error | Error |
20 V | Error | Error | Error | Error | Error | Error | Error | Error | Error |
|
|
|
|
|
|
|
|
|
|
The table above demonstrates the decreasing accuracy of the DC-DC buck converter circuit as the input voltage decreases from the ideal 20 V down to 12 V. Figure 12 is a plot of the data, and clearly shows that operating at a solar panel voltage of 20 V provides the best DC-DC buck performance in terms of accuracy. The buck circuit would provide fluctuating values when asked to output a voltage equal to the input voltage.
Signal | Rise Time | Fall Time | Percent Overshoot | Average Voltage |
PMOS Input | 55.6us | 472.0 ns | 1.1 % | 7.2 V |
PMOS Output | 56 ns | 17.20 us | 1.0 % | 13.4 V |
Current Divider:
The 3.35 V is read into the Arduino Uno analog input pin A5 from the voltage divider at the load attached to the DC-DC buck converter circuit. Using the 1kresistors, their ratio of the voltage divider translates 3.35 volt to 13.4 volts. This matches with the desired output of 13.2 volts.
Through Ohm’s Law, Input Current IIN in can be measured with a series resistor at the DC-DC Buck Circuit input :
The power from the solar panel can then be calculated:
Login