Isolation and Dispensing of DC-to-DC Power Supply to High Power Electrical Application Circuits

Abstract

The suggested system is constructed using a line voltage of 220V/50Hz as input, which is stepped down, rectified, then admitted through a filter capacitor to produce an unregulated DC voltage. This uncontrolled voltage is stepped down to provide a steady 15v supply to the IC, which is controlled by a PWM signal to control the output voltage level to the various applications. To isolate the DC output from the input source, a Separation Transformer is employed. The transformer output is rectified again by the high frequency Diode bridge rectifier and filtered with a capacitor to provide the regulated DC output. To provide correct voltage output, a voltage regulator is installed. The feedback network generates a high frequency PWM signal that drives the MOSFET switch. The DC voltage at the output is determined by the width of the switching pulse. The pulse width varies in response to fluctuations in the DC output voltage level; this variation in the pulse width eliminates the output voltage variation, and the SMPS output stays constant independent of load dissimilarities