Publication: Design a dc power supply large capacity without isolation transformer
Loading...
Date
2008-05-01
Authors
Hussain, Norhaliza
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
A dc power supply large capacity is design without transformer isolation. A transformer has been replacing by a buck regulator which is used to step down the ac input voltage to dc output voltage. A buck converter topology has been used in designing a 1200W switch mode power supply to replace the transformer isolation. To design this power supply, the parameters value is need to calculate first. A three-phase bridge rectifier has been built on a prospect by using six diodes type 40HF(R). It is use to convert an ac voltage to dc voltage. Then, a PWM switching is built on PCB by using SG3524 IC and IR2110 to generate a trigged waveform to give a signal to MOSFET to switch on or off the circuit. In this project, the duty cycle, k = 76% and a switching frequency, f = 100 kHz have been fixed. The output can be observed by using oscilloscope. Then, circuit of buck converter is built and tests are done in the circuit. All circuit, rectifier, switching and buck regulator has been combined together to do a test. As a result, the circuit is can function, but it is not stable while operate. This project only can operate with input voltage up to 60V and the duty cycle up to 50% only.