We often see voltage fluctuations in electricity supply at our home, which may cause malfunction in our home AC appliances. Today we are building a low cost High and Low Voltage Protection Circuit, which will cut off the power supply to the appliances in case of High or Low voltage. It will also show a alert message on 16×2 LCD. In this project, we have used PIC Microcontroller to read and compare the input voltage to the reference voltage and take the action accordingly.
Programming part of this project is easy. In this code, we just need to calculate AC voltage by using mapped 0-5v voltage coming from Voltage Divider Circuit and then compare it with predefined values. You can check the complete PIC code after this project.
First, in the code, we have included a header and configured the PIC microcontroller config bits. If you are new to PIC coding then learn PIC Microcontroller and its configuration bits here.
Circuit and PCB Design using EasyEDA:
To design this HIGH and LOW Voltage Detector Circuit, we have chosen the online EDA tool called EasyEDA. We have previously used EasyEDA many times and found it very convenient to use compared to other PCB fabricators. Check here our all the PCB projects. EasyEDA is not only the one stop solution for schematic capture, circuit simulation and PCB design, they also offer a low cost PCB Prototype and Components Sourcing service. They recently launched their component sourcing service where they have a large stock of electronic components and users can order their required components along with the PCB order.
While designing your circuits and PCBs, you can also make your circuit and PCB designs public so that other users can copy or edit them and can take benefit from there, we have also made our whole Circuit and PCB layouts public for this High and Low Voltage Protection Circuit, check the below link:
Below is the Snapshot of Top layer of PCB layout from EasyEDA, you can view any Layer (Top, Bottom, Topsilk, bottomsilk etc) of the PCB by selecting the layer form the ‘Layers’ Window.