## 3 Results
### Main Results  
Table 6 illustrates the data obtained from the photovoltaic panel in one complete reading sweep using the resistive load data acquisition system. The first measurement was taken with all relay module channels turned off, meaning the photovoltaic panel was in an open-circuit condition. Subsequent measurements were taken using different resistor combinations from the resistor bank. The entire data acquisition process takes 45 s and successfully automates the switching of the load applied to the PV panel. Readings were taken at 30 min intervals between 9:00 a.m. and 4:00 p.m., totaling 15 measurements. The analysis presented in this paper is based on the data collected during this single day of operation. The data shown in Table 6 illustrates the importance of using a system to apply loads to electric generators, since the power generated varies according to the load applied, and it is necessary to obtain the device's maximum power value to determine its efficiency. Another advantage of the system is that the time of each acquisition is recorded, allowing the efficiency of the device to be calculated correctly from the solar irradiance value collected at the same time as the maximum power acquisition. It is important to note that of the 256 possible associations, only 23 were selected to reduce the measurement time. If all 256 possibilities were carried out, it is estimated that the data collection time would go from 45 s to approximately 501 s. The first measurement (Index 0 from Table 6) corresponds to the open-circuit voltage of the PV panel. Furthermore, as can be seen in As in Figure 9a, depending on the conditions to which the generator is subjected, in this case, a photovoltaic panel subjected to different solar  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Time** & **Index** & **Resistive Load [\(\Omega\)]** & **Voltage [V]** & **Current [A]** & **Power [W]** \\ \hline
14:02:06 & 0 & \(\infty\)* & 20.6 & 0.0 & 0.0 \\
14:02:08 & 1 & 100.4 & 20.5 & 0.3 & 5.6 \\
14:02:10 & 2 & 48.0 & 20.4 & 0.4 & 9.1 \\
14:02:1  
irradiance values (G) and operational temperatures (T\({}_{\rm op}\)), the maximum power value can be obtained with different resistive loads. It can also be observed that the range of resistive load values applied to the photovoltaic panel was sufficient to achieve the maximum power value even under varying solar irradiance conditions. The data acquisition system was also able to observe the characteristic curve of the photovoltaic panel under the incidence of different average levels of solar irradiance, as can be seen in Figure 9b. Even though these results were not obtained under controlled temperature and solar irradiance conditions, the behavior shown is very similar to what is expected for these devices, in which higher solar irradiance values tend to increase the voltage and current values of the photovoltaic panel, with the most significant increase being in the current, which consequently increases its power. Figure 9b also shows the comparison between the DAQ and model data for the I-V curves and output power for each G and T\({}_{\rm op}\) condition. It can be seen that, in general, the model was able to predict the same behavior for the I-V and output power curves; however, there were some difference in absolute values compared to the measurements from the DAQ. Figure 10a,b illustrate the importance of acquiring data quickly. When operating the device under ambient conditions, it is exposed to variations in solar irradiance. Figure 10a shows the panel's characteristic curve obtained from an acquisition made with constant solar irradiance, while Figure 10b shows the acquisition with variations in solar irradiance. If the acquisition is done slowly, the likelihood of the panel being exposed to different G conditions is greater, making it more difficult to characterize the device.