Abstract: The main goal of this project is to offer an uninterrupted power supply to a load by automatically picking a supplysource from among four options: mains, generator, inverter, and solar in the event of a power outage. The need for electricityis growing by the day, and frequent power outages are generating several problems in enterprises, hospitals, and homes. As aresult, a different power source arrangement is desirable. This project uses four switches to demonstrate and activate thefailure of the power supply source. When either of the switches is pressed, it indicates that the source is not present. Thisproject uses four switches to demonstrate and activate the failure of the power supply source. When either of the switches ispressed, it indicates that the source is not present. As input signals, switches are linked to the microcontroller. Themicrocontroller is from the 8051 family. The relay driver IC receives the microcontroller's output and switches theappropriate relay to maintain continuous power to the load. Initially, output is measured using a bulb that draws electricityfrom the mains. When the mains supply fails (which is triggered by pressing the relevant switch), the load is supplied by thenext available source, which is an inverter. If the inverter fails as well, the system changes to the next available source, and soon. An LCD also shows the current condition, such as which source is giving power to the load. Due to the impossibility ofproviding all four different sources of supply, one source with an alternate parallel configuration is provided fordemonstration purposes. However, four separate sources can be used if they are accessible. Other sources of energy, such aswind power, can be added to the project, and the best potential power source – the one with the lowest tariff at the time – canthen be considered.