The goal of this project is to create a multiple output cell phone charger for the DC House project. The cell phone charger is essentially a DC-DC converter. The converter takes an input of 48 volts from the outlet in the DC House and decreases the voltage level to 5 volts; the input voltage level of all cellular devices.
By designing an isolated flyback converter with initial specification in LTSpice simulation software, a converter was created. By monitoring the input and output voltage and current using the multi-meters and electronic load, we determined the charger to be 71% efficient when both outputs were running at a full load of 1 ampere. Using the same equipment the load and line regulations were determined.
Output one had a load regulation of 1.35% and a line regulation of 0.34%. Output two had a load regulation of 2.02% and a line regulation of 0.3%. By viewing each output on the oscilloscope, we determined the voltage ripple of each output to be 3.45% and 4.42%. With these results, we know we have created a quality and affordable multiple output cell phone charger.
Source: California Polytechnic State University
Authors: Andrew Hefner | Antonio Magdaleno