Paper Title
Design And Development Of Battery Charger For Online Ups Using PIC Microcontroller

Abstract
The proposed on-line uninterruptible power supply (UPS) offers AC voltage regulation on continuity basis which incorporates with the controllable battery charger. The charge control technique used for battery is constant current charging technique. The Constant Current is achieved by limiting the duty cycle of charger (or step-down chopper). Based upon the proposed constant current charging technique, a digital charger is designed and is control through PIC 16F877A microcontroller software. In proposed scheme, protection of battery over charge and battery under discharge is available with relay trip through PIC 16F877A microcontroller by monitoring voltages on continues basis. The backup of battery takes place the load without spikes or delay when the mains power gets fails or interrupted. Experimental results using PIC 16F877A microcontroller controlled battery charger cum rectifier is presented to shows the effectiveness of the proposed design. Keywords- UPS - Uninterruptible Power Supply, PIC - Peripheral Interface Controller, LCD - Liquid Crystal Display