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In this era due to Power electronics revolution, people have very efficient tools to solve problems of having DC voltage to power the Electronics Devices. Every new electronic product requires converting input voltage 230V AC power to some fixed DC voltage for powering the electronics circuit or devices. Switching regulators (SMPS) are becoming an essential part of many electronic systems due to miniaturization and energy efficiency. Conventional power supplies, however, draw currents that are highly non-sinusoidal and out of phase with input voltage, thus display a low power factor and higher total harmonic distortion (THD), which causes power quality problems. In This work presents two stage AC-DC and DC-DC power converter using single-phase isolated Full bridge converter with inherent power factor correction (PFC) method for switched mode power supply (SMPS).The advantages of the proposed methodology are its simple control strategy, reduction in complexity of system, low input line current harmonics. The effect of load variation on SMPS is also studied in order to demonstrate the effectiveness of converter for the complete range of load conditions.

Complete UBV light-curves of RR-Lep and RX-Hya have been obtained during 1983-87 seasons. Preliminary elements were computed using modified Wellmann's method. With these parameters as inputs Wilson-Devinney program was executed for Blue and Yellow passbands simultaneously in detached and semi-detached modes for both the systems. The semidetached mode fitted better than the other solution for both the systems. For RR-Lep, the absolute dimensions were computed by assuming the primary to be a slightly evolved main sequence star. For RX-Hya, the absolute dimensions were computed using Struve's spectroscopic data. The following table gives all the elements for both the systems. The secondaries of both the systems are overluminous for their masses suggesting that they have lost considerable mass.

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