Abstract: A DC-DC boost converter with constant output voltage is designed to solve such drawbacks of common DC-DC boost converter as low efficiency,excessive ripple voltage and output voltage instability.The fluctuating input voltage is changed to constant DC voltage output by using the boosting circuit and the voltage feedback technique.Comparing the converter output voltage with the reference voltage,the differential of the compared value generates a PWM signal to control the switch time,thus achieving a constant voltage output.The simulation results show that the designed circuit could produce a constant output voltage of 24 V,an output power of 100 W,and a switching frequency of 20 kHz in continuous conduction mode.

Key words: DC-DC;boost converter;solar system;constant output voltage;PWM