The paper presents design and performance evaluation of two-stage ac adapters for notebook computers which deliver 70 W from the universal line. Three versions of the flyback converter, as well as the PWM and resonant half-bridge converter were evaluated and compared with respect to their efficiency, component stress, output filter size, and complexity.

A novel soft switching PWM converter for high frequency ACIDC andlor DCIAC power conversion is presented by using a new parallel resonant dc-link(PRDCL) and by adopting single phase soft switching(SPSS) technique. The new PRDCL provides variable link pulse position as well as variable link pulse ,width. which is quite different feature from the other resonant dc-links and thus the PWM capabilit...

This application note describes the LED driving system using a half-bridge LLC resonant converter for high power LED lighting applications, such as outdoor or street lighting. Due to the existence of the non-isolation DC-DC converter to control the LED current and the light intensity, the conventional PWM DC-DC converter has the problem of low-power conversion efficiency. The half-bridge LLC co...

This paper proposes a high efficiency DC-DC flyback converter with a resonant full-bridge inverter to use in PV systems. The flyback converter is composed of a resonant active-clamp circuit that limits the voltage stress and provides zero voltage switching (ZVS) turn-on and turn-off of the power switches. Therefore, the switching losses of the high frequency primary switches are negligible. A r...

To achieve the soft-switching condition and stabilize the output voltage of quasi-resonant converters, the paper proposes a double closed-loop control method (DCCM). In the inner loop, soft-switching is guaranteed with the off-time of the switch determined by the zero-crossing signal of the switching voltage. In the outer loop, the output voltage is regulated to be constant against load variati...

This paper addresses the impact of power devices switching characteristics on design and performance of pulsewidth-modulated current stiff converter (CSC) topologies with resonant snubbers. The MOS turn-off (MTO) thyristors were selected for this study due to their high voltage and current ratings, simplified gate drive circuitry, unity gain turn-off, greatly reduced storage time allowing highe...

The main purpose of this paper is to develop a novel application of a resonant switch converter for battery chargers. A zero-current-switching ZCS converter with a quasiresonant converter QRC was used as the main structure. The proposed ZCS dc–dc battery charger has a straightforward structure, low cost, easy control, and high efficiency. The operating principles and design procedure of the pro...

This application note describes the LED driving system using a half-bridge LLC resonant converter for high power LED lighting applications, such as outdoor or street lighting. Due to the existence of the non-isolation DC-DC converter to control the LED current and the light intensity, the conventional PWM DC-DC converter has the problem of low-power conversion efficiency. The halfbridge LLC con...

Purpose – To derive an analytical model for a dc-ac-dc parallel resonant converter operating in lagging power factor mode based on the steady-state operation conditions and considering the effects of a high-frequency transformer. Design/methodology/approach – A range of published works relevant to dc-ac-dc converters and their control methods based on pulse-width-modulation technique are evalua...

Generally converter when operated at high frequency results in losses. In this paper a single stage soft switching PFC converter analysis is done. It is developed with a new active snubber cell which provides zero-voltage transition turn ON and zero-current transition turn OFF. This type of converter circuit design does not have additional resonant components. Operating the proposed converter a...