Slamet Hani

The source of water flow in rivers or irrigation canals has a relatively small flow rate of water, which can be used as a pico hydropower plant. One of the main components of a pico hydropower plant is a water wheel, a hybrid pico hydropowerplant is a combination of hydroelectric power and solar power. By utilizing the power of the water flow in a small river or ditch in Wukirsari hamlet, we designed a waterwheel that will convert the energy of motion into electrical energy. The solar panel system designer uses a 50 wp solar cell, a 300 W inverter, a 10 Ampere solar charger controller, and a 12 Volt, 32 Ah battery. The no-load test results on the performance of the single pinwheels and the performance of the double pinwheels at a water level of 37 cm get an average power of 3.2 W and 2.11 W. The resulting voltage is 6.72 V, the current is 0.46 A for a single mill, while for the double pinwheel the voltage is 5,26 , and the current is 0.38 A. From the experimental results, it is better if the single pinwheel and the double pinwheel are used. In a series of no-load solar panels fromPower test results, at 11.00 GMT+7 the highest power value was 33.25 W. The electricity generated by the pico hydro hybrid was used by the people of Wukirsari Hamlet as street lighting.   Key words: water wheel, hybrid power, solar panels

Tanaman padi yang subur akan menghasilkan gabah yang banyak. Pemberian pupuk dengan komposisi yang tepat sangat membantu pertumbuhan tanaman padi. Salah satu faktor untuk irigasi air yang tepat adalah melakukan monitoring lingkungan fisik tanaman padi seperti nilai kelembaban dan suhu tanah. Nilai kelembaban tanah menjadi indikator tanaman padi dapat menyerap nutrisi yang tesedia dengan baik atau tidak. Sistem monitoring kualitas tanah tanaman padi dengan parameter perubahan kelembaban dan suhu tanah berbasis internet of things akan membantu petani dalam menentukan debit air yang sesuai. Penerapan sistem kendali jarak jauh pada sistem monitoring ini telah berhasil diterapkan dengan kecepatan rata-rata pengendalian sebesar 1,2 s. Hasil penelitian menunjukan bahwa nilai kelembaban tanah sangat berpengaruh terhadap hasil panen, yaitu dengan nilai kelembaban 53% menghasilkan 800 kg gabah dari lahan seluas 600 m sedangkan dengan nilai kelembaban tanah sebesar 68% menghasilkan 500-600 kg gabah dari lahan seluas 350 m.

In general, one of the main components used in electric power systems is a transformer. In principles, this equipment uses a magnetic process through the pairing winding where a cooling system is also applied to maintain the expected operational performance and to maintain heat transfer during the power delivery. In fact, load demand changes fluctuate depending on the behavior of energy users. This research is conducted to evaluate heat transfer in a three-phase transformer. This work also takes into the flowing current gradually based on the heat generated in the transformer. To cover these objectives, the analysis is directed to the power transformer optimization using the Artificial Salmon Tracking Algorithm (ASTA) for performing heat flow rates on-demand changes. The results obtained indicate that ASTA has a potential implementation for determining the optimal heat transfer. The demand changes have affected the power loss detected in both windings which are migrated out of heat through the cooling and fluid systems.

A Centrifuge is one very important medical apparatus for separating some me-dical subtracts such as blood, urine, drugs for producing vaccines and antitoxins. Ba-sically this apparatus is centrifugal turntable equipped with a study turning mechanism and a set of tube holders to accommodate 4 up to 20 subtract sample tubes. The needed rotation controlling system was designed and constructed in steps. First, for the entire mechanical as well as electronic subsystem. Second, on the details of the electronic hardware and the connected mechanism. Third, the software needed to run the electronic hardware. Fourth, to load the controlling program into the AT89C51 microcontroller and finally the run test of the entire system. The result shows that this centrifuge regulator works sufficiently well to replace the original failing system.