In Indonesia and many countries for economic reasons and green energy LPG is widely used for cooking. This paper show implementation and design gas leakage detection system. The main objective of the project to build a gas LPG leakage detector using an LPG gas sensor and micro-controller. It developed a security system by providing an early Warning System to give a sign if there is a smell of gas around Home. If this system has been the existence of leakage and smell of LPG gas, then the system will give a sign of alarm or buzzer where if there is leakage of gas that smelling the LPG system will work and the early warning alarm of the system. That the presence of gas leakage signals on the sensors to work, the MQ-6 is the gas Sensor used to detect leakage gas LPG. The tool is designed to detect gas leaks that are then legible on the LCD screen and alarm, and in certain circumstances, the buzzer will sound. This MQ-6 sensor test is performed by measuring the sensor output with the Atmega8 microcontroller when the LPG gas is detected and then writes it on the LCD screen. This test was conducted to determine the contribution of the MQ-6 sensor. It becomes essential to protect gas leakage from damage and accident.

Electric energy savings are influenced by magnitude of reactive power used by electric customers, one of the tools that can minimize reactive power is the inverter, which is an electronic equipment, that can change the direct current of electricity to alternating current, The method used is by measuring along with analysis of calculation each time the inverter is given the burden of energy-saving lamps with varying power to determine the change in the electrical quantities to be analyzed. Inverter efficiency in doing the convert direct current to alternating current during low load (5W) amounted to 94.66%, and the highest load current (203W) amounted to 90.55%.

In general Audio Amplifier using linear transformer-based power supply as energy conversion. Such use may cause interference with electrical installation sourced from the substation circuit. The non-linear load would cause problems in the electrical installation system. This research shows that Switch Mode Power Supply (SMPS) has a minimum voltage Vdrop output load of about 100 to 33.33 ohms. On the burden of 25-20 ohms as the voltage Vdrop output, which is different from Linear Power Supply Transformer-based parameters, that its voltage Vdrop output was changed significantly.

The sun shines on the territory of Indonesia for about 10 to 12 hours every day, so that solar power plants can be developed in Indonesia, the government has launched the movement of one million PLTS roofs in 2017, this research uses solar panels with a capacity of 200 Wp, which consists of 2 solar panels connected in parallel, solar charge controllers, batteries, inverters and as an AC load a fan, soldering iron and LED lights, the research aims to determine the output current, voltage and output power of the inverter when given an alternating current load that is inductive, resistive and capacitive, the method used is to measure the intensity of the sun, temperature, voltage, electric current, power factor, when the load is large the voltage drops depending on the given load, the inductive fan load has a voltage drop that is greater than the voltage drop that occurs in the soldering load and the LED lamp, the large current flowing on the output side fan load wants to be bigger than output current flowing in the solder and LED lights, the low efficiency of the inverter used can shorten the life of the electrical equipment used.