Over / Under Voltages Cut-Off With On Time Delay

Abstract

The general purpose of voltages cut-off circuit is to give the protection with time delay to avoid equipment from damages due to over or under voltages condition. The over or under voltage protection circuit with time delay presented here is a low cost and reliable circuit for protecting such equipments from damages. Whenever the power line is switched on it gets connected to the appliance only after a delay of a fixed time. If there is high or low fluctuations beyond sets limits the appliance get disconnected. The system tries to connect the power back after the specific time delay, the delay being counted from the time of disconnection. If the power down time (time for which the voltage is beyond limits) is less than the delay time, the power resumes after the delay: If it is equal or more, then the power resumes directly. The power line fluctuations and cutoffs causes damages to electrical appliances connected to the line. It is more serious in the case of domestic appliances like fridge and air conditioners. If a fridge is operated on low voltage, excessive current flows through the motor, which heats up, and get damaged. This research study reviews the types and configuration of voltages cut-off with time delay systems. This will then be applied as case studies to test and validate the proposed reliability estimation methods. The research study will concludes with recommendations on the most suitable and reliable voltages cut-off with time delay system.