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Along with developments in the maritime sector, especially on ships, the need for electric power on board will be very diverse. The use of diesel engines as power plants requires fuel to drive a diesel while the use of fuel in ships produced from petroleum processing is limited. Efforts to reduce the use of fuel is by implementing new renewable energy as independent electricity on ship. In EBT inverter technology plays an important role in converting DC voltage to AC voltage. In the inverter, the use of microcontrollers as drivers to generate PWM signals continues to develop. One of the developments of the microcontroller is ESP32. The problem that often occurs in inverters is that the output voltage is unstable. In addition to maximizing the performance of the inverter, it is necessary to add a protection system to reduce the risk of damage to the inverter or the load. Therefore, an inverter was made using the ESP32 microcontroller driver with the addition of protection and the fuzzy method as a voltage stabilizer. This inverter will change the 12 Vdc to 220 vac. In the Matlab simulation, the inverter can change the 12 vdc to 12 vpeak with a carrier signal of 20 khz and a reference signal of 50 hz. From the results of the inverter output will be changed to 220 vac using a step up transformer. The research overlay is being able to make a pure sine wave SPWM inverter using an ESP32 driver with a stable voltage.

Gedaren Spring is an important source of clean water and irrigation water that is located in the transition zone between the Gunungsewu Karst and the Wonosari Basin. Limestone dissolution is the dominant process influencing this epikarst spring’s dynamics, but there has been no temporal hydrogeological testing on its ion content. This hydrogeochemical study was intended to determine the characteristics and quality of Gedaren Spring water during the rainy season. The methods used in the chemical analysis were Schoeller, Piper, and chemographic diagrams, and the results were correlated with spring discharge measurements and rainfall. The chemical analysis showed a positive correlation between discharge and rain, the temporal presence of dominant ions, and temporal correlation patterns between variables. Ca2+ and HCO3- were the dominant cation and anion. The spring water was classified as calciumenriched, calcium, bicarbonate, Ca2+ + Mg2+, and HCO3--type groundwater and as unpolluted groundwater, suggesting good water quality. Chemographic patterns indicated that Mg2+, Cl-, and SO42- ions positively correlated with discharge and rainfall, while Ca2+, HCO3-, Na+, K+, pH, EC, temperature, and TDS negatively correlated with the two variables. Overall, Gedaren Spring has good chemical characteristics and quality during the rainy season has a dominant process of calcium enrichment and is of the type Ca2++Mg2+ and HCO3-.