International Science and Technology Journal

The main objective of this study is to ensure the continuity of supplying electrical power to a load from two different sources automatically. The main source of the circuit built is photo-voltaic cells connected to the batteries, where the alternative source is a source of direct Current as well; it only provides a continuous feed as a conventional source. The designed system relied mainly on the Arduino Uno controller to shift between the two sources connected to the load; this process requires specific codes for the controller to manage voltages values, where the supply priority has been given to the photovoltaic cell to feed the load. Protues software has been used to Design the circuit, because it has a comprehensive library containing the components required for the controlling process, and management of supplying power from several sources. Arduino Uno reads voltages by Circuit of voltage divider connected to the batteries, which is analog conversion value (ADC). When the controller reads the voltage value equal to or greater than the value of the ADC, the Lamb connected as a load will use the battery as the main source. In case of voltage value of the battery drop down, the ADC value will also fall, which leads give the command to stop the voltage coming from the battery, and switching the power generated from the alternate source automatically. The results of the circuit designed are positive, where such a system can be applied in a practical manner.