Evaluation of the Performance of the Audio Bio Harmonic System

Study Case Evaluation of the Performance of the Audio Bio Harmonic System (ABHS) with Solar Energy Sources Michael Kurniawan (2018123456) University of Cincinnati, 2600 Clifton Ave, Cincinnati, OH 45221, United States kurniaml@mail.uc.edu Abstract This study aims to analyze the performance improvement of the solar-powered Audio Bio Harmonic System (ABHS), focusing on battery life during sound exposure, battery charging time, and sound intensity range. The study was conducted in four main stages. First, a literature review on ABHS was conducted, and the necessary devices and components were prepared. Second, testing was conducted on the previous version of ABHS to evaluate its durability and battery charging time. Third, the ABHS system was developed through circuit modification and component replacement to better suit performance requirements. Fourth, testing was conducted on the developed ABHS, covering battery life, charging time, and sound intensity range. The test results showed a significant improvement in performance compared to the previous version. Battery life increased from 4 hours and 20 minutes to 5 hours and 40 minutes at maximum volume. Battery charging time increased from 1.5 hours to 5 hours due to an increase in capacity from 900 mAh to 3313 mAh. Sound intensity range testing also showed an increase from 92.5 dB to 101.7 dB at a distance of 1 meter, and from 45.1 dB to 65.75 dB at a distance of 60 meters. Keywords: ABHS, cicada sound, performance, solar panel, sonic bloom. INTRODUCTION The United States is one of the most advanced agricultural countries that maintains a balance between modern technology and sustainable agricultural practices. According to the U.S. Department of Agriculture (USDA, 2020), about 40% of rural areas in the United States have active agricultural sectors that contribute significantly to the national MICHAEL KURNIAWAN 1 Study Case economy. Fertile regions, especially in the Midwest such as Iowa and Nebraska, have great potential for food production. Therefore, increasing agricultural productivity through technological innovation is an important focus for this sector. One innovation that is increasingly being studied is sonic bloom technology, which is the application of high-frequency sound waves to stimulate plant growth without causing environmental disturbances (Utami & Purwanto, 2016). This technology works by utilizing sound waves with a frequency of 3,500–5,000 Hz, which can accelerate the opening of leaf stomata and strengthen the photosynthesis process (Suryadarma et al., 2019). Sound waves trigger microscopic vibrations in leaf tissue, allowing for increased absorption of CO₂ and water (Islamiya, 2022). Kadarisman et al. (2011) also confirmed that sound resonance increases internal pressure in leaf tissue, resulting in more optimal stomatal opening. This concept was then developed into the Audio Bio Harmonic System (ABHS), a system based on natural animal sounds used to stimulate plant growth. Research by Kadarisman et al. (2011) shows that the use of natural sounds from insects such as crickets, grasshoppers, and cicadas (garengpung) at a frequency of 3,000–5,000 Hz can significantly increase horticultural yields. Various previous studies have proven the positive effect of exposure to sounds of certain frequencies on plant growth. These results were obtained by comparing treatment and control variables. Geographically, the United States has high solar energy exposure, especially in the southwestern regions such as Arizona, Nevada, and California. This makes the application of solar panel technology an appropriate choice to support energy efficiency in portable electronic systems, including devices such as ABHS. According to a report from the U.S. Department of Energy (DOE, 2022), the efficiency of modern solar panels allows various agricultural equipment to use clean energy at a low cost. Based on this potential, this study aims to improve the performance of solarpowered ABHS without changing the portable size of the previous version. The improvement was carried out through a comprehensive evaluation of each component so that the system could operate optimally. MICHAEL KURNIAWAN 2 Study Case METHOD Preparation Stage The initial stage begins with a literature review focusing on the selection of appropriate modules and electronic components for ABHS. This review forms the basis for the design of the new system and analysis of the weaknesses of the previous version. After that, the necessary tools and materials are prepared, such as electronic modules, solar panels, and measuring devices. Not all components are replaced; only those that directly affect performance. The equipment used includes a digital lux meter, digital multimeter, sound level meter, timer, measuring tape, soldering tools, heat shrink tubes, and screwdrivers. The main components included a 10 Wp monocrystalline solar panel, MPPT solar charge controller, 3S 20A BMS, lithium battery pack, DC multimeter display, 12-watt horn speaker (8 ohms), battery holder, PAM8610 amplifier module, DFPlayer Mini, SD card, and various supporting connectors and capacitors. Initial ABHS Testing Phase Initial testing was conducted to evaluate the performance of the old system, particularly battery life and charging time. The battery was tested by running the system at maximum volume until it reached the minimum operating voltage. Charging tests were conducted using a 10 Wp monocrystalline solar panel, assisted by a lux meter and digital multimeter to monitor test parameters. System Development Stage This stage involves assembling the new version of the ABHS system based on the design from the previous study. Before assembly, all components are tested to ensure their functionality. Cicada sounds (garengpung) are stored on an SD card as the sound source. The system is divided into two main parts: the sound module and the power supply module, which are then combined into a single ABHS system. Figure 1. Solar ABHS Component Configuration Diagram MICHAEL KURNIAWAN 3 Study Case Design System Testing Stage This stage aims to assess the effects of component replacement and adjustment on system performance. The parameters tested include: • Battery usage duration in producing sound, • Charging time, and • Sound intensity range. During testing, data was collected every 10 minutes, from minimum to maximum voltage. The LED indicator on the MPPT module was used to monitor the charging status (red = charging, green = full). Sound intensity testing was conducted using a sound level meter at a distance of 1 meter and extended to 60 meters, with measurement intervals of every 30 minutes in an open area. Environmental factors such as wind speed were taken into account as they could affect the sound intensity measurement results. RESULTS AND DISCUSSION Initial test results on the previous version of the Audio Bio Harmonic System (ABHS) solar power system showed that the device could operate for 4 hours and 20 minutes at maximum volume. It took 1.5 hours to fully charge the 900 mAh battery using a 10 Wp monocrystalline solar panel. The sound intensity produced reached 92.5 dB at a distance of 1 meter and 45.1 dB at a distance of 60 meters. After development, the ABHS system was retested to assess performance improvements resulting from component modifications and circuit adjustments. Battery Endurance Testing Battery endurance testing was conducted by operating the ABHS at maximum volume to determine the device's operating duration from a full battery to the minimum operating voltage. The initial battery voltage was recorded at 12.1 volts. When the volume was increased using an amplifier, the voltage temporarily dropped to 11.6 volts due to the increased electrical load. However, this decrease was temporary; when the volume was returned to its initial position, the voltage rose back to its original value. MICHAEL KURNIAWAN 4 Study Case Figure 2. Graph of Battery Voltage Decrease over Operational Time Figure 2 shows the relationship between operating time and battery voltage. The graph shows that the ABHS can operate for 5.7 hours at maximum volume. The battery voltage decreases linearly until the 300th minute, then drops sharply from 9.3 volts to 8.1 volts in the last 30 minutes. This indicates that at a voltage of 9.3 volts, recharging is needed immediately to keep the device functioning optimally. Table 1. ABHS Battery Drain Data The test results show that when the ABHS is operated at maximum volume until the minimum voltage (around 8 volts), the current flowing varies between 0.72 A and 0.64 A. The system power consumption is recorded at 8.35 watts when the battery is fully charged and decreases to 5.95 watts as it approaches the minimum operating limit. MICHAEL KURNIAWAN 5 Study Case Figure 3. Sound Intensity Change over Time Graph (Distance 1 meter) Figure 3 shows that the maximum sound intensity produced by the system reached 101.7 dB at the start of operation. During the 5.7 hours of testing, there was no significant decrease in sound intensity. A small, linear decrease occurred in the first two hours, then stabilized for the next three hours, and decreased to 97.6 dB towards the end of the test due to a decrease in battery voltage. Battery Charging Test The charging test began by measuring the relationship between sunlight intensity and solar panel output voltage. Measurements were taken using a digital lux meter to record the level of illumination received by the panel, and a digital multimeter to measure the DC voltage generated. Table 2. Sunlight Intensity and Solar Panel Voltage Data MICHAEL KURNIAWAN 6 Study Case The measurement results show that the higher the light intensity, the greater the voltage generated by the panel. In sunny weather conditions, the light intensity ranges from 60,400–67,800 lux, producing a voltage close to the panel's maximum specification value. Figure 4. MPPT Input and Output Voltage vs. Time Graph Table 3. MPPT Input and Output Voltage Data The output voltage of the MPPT Solar Charge Controller is set at a maximum limit of 12.6 volts. This voltage tends to increase during the charging process until it approaches full capacity. A voltage drop occurred at the 150th minute due to a decrease in sunlight intensity, as recorded in Table 3. MICHAEL KURNIAWAN 7 Study Case Figure 5. Battery Voltage Graph over Charging Time The battery charging process using solar panels was carried out to assess the capacity of the Rakkipanda 3S battery. The graph in Figure 5 shows a relatively linear increase in voltage during sunny weather conditions, indicating a stable charging current. Table 4. ABHS Battery Charging Process Data Using Solar Panels From the test results, charging the battery from 8 volts to 12.1 volts took approximately 5 hours. The charging current is inversely proportional to the voltage: the higher the battery voltage, the smaller the incoming current. The charging process is indicated by a change in the MPPT indicator color from red (charging) to green (full). At 14:10, the current dropped to 0 amperes, indicating that the battery capacity had been fully reached. MICHAEL KURNIAWAN 8 Study Case Table 5. Battery Capacity Data Based on Voltage The electrical charge capacity stored after full charging reached 3313 mAh, slightly higher than the nominal capacity of 3000 mAh due to manufacturing variations. When the battery voltage reached 12.1 volts, a total electrical charge of 3313.34 mAh was obtained from the multiplication of the average current and the charging duration. Sound Intensity Level Testing This test was conducted to assess changes in sound intensity at various distances, from 5 meters to 60 meters, using a sound level meter. Figure 6. Sound Intensity vs. Distance and Time Graph The test results show that the maximum intensity of 86.55 dB was achieved at a distance of 5 meters, while the minimum value of 61.84 dB was recorded at a distance of 60 meters. Based on the reference by Ai et al. (2021), an effective sonic bloom method uses sound with an average intensity of 65–75 dB at a frequency of 3–5 kHz. Thus, the developed ABHS system has shown high effectiveness because it is able to maintain stable sound intensity up to a distance of 60 meters. MICHAEL KURNIAWAN 9 Study Case Table 6. Comparison of New and Old ABHS Performance CONCLUSION This study successfully improved the performance of the solar-powered Audio Bio Harmonic System (ABHS). The test results show a significant improvement in three main aspects, namely: 1. Battery life increased from 4 hours 20 minutes to 5 hours 40 minutes at maximum sound intensity. 2. Battery capacity increased from 900 mAh to 3313 mAh, with a full charging time of approximately 5 hours using a 10 Wp solar panel. 3. The sound intensity range increased from 92.5 dB to 101.7 dB at a distance of 1 meter, and from 45.1 dB to 65.75 dB at a distance of 60 meters. Overall, these improvements indicate that the latest version of the solar-powered ABHS system is more efficient, has a longer service life, and is capable of producing a wider sound range than the previous version. MICHAEL KURNIAWAN 10 Study Case REFERENCE MICHAEL KURNIAWAN 11