This paper discusses about controlling the buck boost converter output voltage remains constant by comparing of loads resistor and battery. Buck boost converter output voltage tends to be unstable when given a disturbance with a variety of loads, for that it needs proper control to adjust the duty cycle. The controls that will be used are a combination of conventional control methods, i. e. Proportional Integral (PI) and intelligent control, i. e. Fuzzy logic. The results show that the combination of PI control and Fuzzy Logic can improve performance, i. e. small errors close to zero and the buck boost converter output voltage remains constant even though the load is varied, i. e. resistors and battery.

The development of technology from year to year is greatly improved, many supporting needs must be prepared specifically for electrical energy needs. The side ofthe distribution of electricity and its utilization must meet the requirements so that in its use can be more optimal and does not cause harm and accidents for humans and loss of property. Kamarora is one of the villages that also uses and utilizes electricity resources in Nokilalaki district. The village has 1 unit of 100 kVA capacity portal type transformer. In this study used measurement methods, customer data collection, and checking directly on the connection in each phase to find out the percentage of transformer loading performance and minimize unbalance of the load transformer. The results of research and analysis, the distribution transformer in Kamarora village have the highest loading conditions with peak load times (PLT) line 1 and 2 at 19:00 pm with a loading percentage value of 60.47 %, the value of imposing a transformer means that it is still underloaded. And then, the unbalance of the load transformer is high enough, the total power used in line 1is phase R (3600 VA), S (9400 VA), T (17400 VA). Line 2 westward is phase R (16150 VA), S (18900 VA), T (21950 VA) and line 2 eastward is phase R (17050 VA), S (18850 VA), T (3850 VA). Planning the load distribution for each line 1 and 2, namely in the line of 1is  phase R (10200 VA), S (9400 VA), T (10800 VA).Line 2 westward is phase R (19250 VA), S (18900 VA), T (18850 VA) and line 2 eastward is phase R (23841 VA), S (23844 VA), T (24188 VA).

Effect of NaCl Immersion Media on Corrosion Rate on ST 42 Steel in Kepok Banana Peel Inhibitor Extraction. This study aims to determine the corrosion rate of ST 42 steel using an inhibitor of kepok banana peel extraction with various NaCl immersion media. Sample immersion time is 168, 336, 504 hours. The method used to calculate the corrosion rate is to measure the weight loss. The sample of this research was carried out in the Mechanical Engineering laboratory, Faculty of Engineering and the Pharmacy laboratory, Faculty of Mathematics and Natural Sciences, Tadulako University. The results obtained in the variation of NaCl 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, inhibitor kepok banana peel extraction 300 ppm, an increase in corrosion rate with increasing NaCl variation with the same amount of extraction inhibitor, this is because the percentage of NaCl variation greatly affects the corrosion rate.

The use of three-phase induction motors in the industrial world is increasingly growing, in addition to industry, the transportation department is also increasingly using induction motors with the development of transportation models that use electricity. But testing in the performance of induction motors is still not applied. Only the industrial world is able to set test standards for the performance of induction motors. Performance can be seen by monitoring how the output speed of the induction motor. This study aims to create a system that is able to see the performance of the induction motor output in a graph in real time and continuously. In the implementation results, it can be seen that the monitoring system can display a graph that matches the reading of the speed sensor mounted on the induction motor.

The rapid development of the world of technology that covers almost all sides of life has encouraged innovation and human creation to make various tools with automatic work systems. Giving fluids using intravenous fluids is one way to enter fluids intravenously to meet the needs of fluids, electrolytes, drug administration, and feeding. The process of replacing intravenous fluids that has reached the minimum replacement limit must be carried out promptly and quickly, so that there will be no delay in changing intravenous fluids which will result in unstable pressure on the infusion set which will result in blood clots.In its testing, this tool can display information on the total number of intravenous fluid drops, and the condition of the remaining infusion fluid level on the LCD, as well as an additional display of the number of intravenous fluid drops per minute on theapplications client PC and / or smartphone. Adjusting the position of the mini servo of the infusion tap, can be adjusted when the appliance is not or not connected to the client. The sensor optocoupler used can also detect every drop of intravenous fluid. The reading of the sensor optocoupler used can experience an error by a difference of 100% if the dripping of the intravenous fluid is too slow. This is caused by the drip that is read twice by the sensor because one drop of intravenous fluid is read again after more than 50 milli second.Key words: microcontroller, nodemcu esp8266, optocoupler, load cell, mini servo sg90, smart infusion.