A self-powered flyback pulse resonant circuit (FPRC) is proposed to extract energy from piezoelectric (PEG) and thermoelectric generators (TEG) simultaneously. The FPRC is able to cold start with the PEG voltage regardless of the TEG voltage, which means the TEG energy is extracted without additional cost. The measurements show that the FPRC can output 102 µW power under the input PEG and TEG voltages of 2.5 V and 0.5 V, respectively. The extracted power is increased by 57.6% compared to the case without TEGs. Additionally, the power improvement with respect to an ideal full-wave bridge rectifier is 2.71× with an efficiency of 53.9%.

This paper presents a novel current driving method for the synchronous rectifier (SR) in a Flyback topology. Compared to the previous proposed Current Driven Synchronous Rectifier (CDSR), the proposed CDSR features simple structure, low power loss and good performance. The proposed SR driving method is implemented in a 64 W Flyback converter with universal input, and efficiency as high as 92.5% is achieved at low input (90 V ac) and full load condition.

In recent years the size of transformer in a DC-DC converter becomes smaller and thinner for power module type application. It results in the increase of the leakage inductances because the number of turns of the secondary winding becomes smaller. This paper presents the analysis of static and dynamic characteristics of the novel flyback converter proposed before, and clarifies that the transformer's leakage inductances deteriorate the static load regulation, but improve the dynamic stability by increasing the dumping factor.

A DC-DC converter using two transformers is proposed. One transformer delivers the energy to a load when a switch is on and the other transfers the flyback energy to a load when a switch is off. The primary windings of the two transformers function as choke inductance alternately, and thus the output voltage control by means of the duty ratio and the zero-voltage-switching are possible without an additional inductor. The breadboarded prototypes of the single output and the two outputs have confirmed the principles of operation and demonstrated the high conversion efficiency.

The proposed high-power-factor converter is constructed with a flyback converter, and locates the energy-storage capacitor on the secondary side of the transformer. A high power-factor can be obtained without needing to detect any current, and the ZVS operation can be achieved without auxiliary switches. To make the best use of these advantages in the converter, ZVS operations and power-factor characteristics in the converter were analyzed. From the analytical results, the effective control method for achieving ZVS was examined. Using a bread-board circuit controlled by this method, a power-factor of 0.99 and a conversion efficiency of 88% were measured.

The designed converter has a two-input-winding transformer powered by single-phase AC voltage and an energy storage capacitor. Small size and enhanced conversion efficiency are achieved, because more than half of the energy is supplied to the load via a single conversion stage, and fast output-voltage regulation is achieved by controlling the charging and discharging of the storage capacitor. The design and control methods for the converter take into account the reset conditions of the transformer and stability in the output voltage control. An almost unity power factor and a low output voltage ripple were achieved with this converter fabricated as a breadboard circuit using small capacitors.

For high frequency video signals, display monitors for personal computers are required to shift from the horizontal scanning frequency fH=15.75 kHz for conventional TV broadcasting to fH=64 to 80 kHz, which is called XGA. Shifting to high frequencies and restrictions on the withstand voltage of horizontal transistors decrease the inductance of deflection yokes, which is an obstacle in manufacturing deflection yokes. A study was undertaken on an operation to permit deflection/high voltage integrated operation while keeping the inductance of the deflection yoke high. This paper reports the results.