Abstract: The present invention discloses an active peak voltage-limiting clamp circuit, which comprises a primary switch unit and a secondary switch unit that are used to control the coil current of a transformer, wherein a signal acquisition unit, a zero-point decision unit, a feedback unit and a pulse control unit are used to control the turn-on periods of the primary switch unit and the secondary switch unit; thus, the turn-on period of the primary switch unit is separated from the turn-on period of the secondary switch unit, and a buffer interval for the transient voltage variation is formed therebetween.

Abstract: A pulse controller with dual latches includes a first latch unit and a second latch unit, in which two latch units are used to latch signal level for ensuring a sufficient conducting amount of the switching element in the rear end power output unit, and through a mutual interaction between the first and the second latch units, a complementary turning-on and turning-off situation therebetween is formed, and further, the signal from a trigger signal source and the feedback from the power output unit are employed to generate the duty cycle signal for the power output unit so as to replace the conventional pulse width modulation circuit.

Abstract: A simple zero current switch circuit includes a first coil set and a second coil set that are wound at a selected coil ratio and bridge electrically an energy storing inductor, an output diode and a conduction switch of a power-factor corrector. The leaking inductance of the first coil set generates a back electromotive force to make the conduction switch in a zero current switching condition. An energy conversion circuit is provided to store reverse energy according to the coil ratio of the second coil set and the first coil set and reclaims the energy to an output capacitor of the power-factor corrector while the output diode generates a reverse recovery condition. Thereby reverse recovery time of the output diode can be shortened.

Abstract: The present invention discloses a self-excitation synchronous rectification driver, which comprises a self-excitation coil, a self-excitation driver, a synchronous-signal source, a pulse transformer, a positive/negative edge detector, and a latch unit. The synchronous-signal source generates a synchronous signal to attain an external synchronous function. When the frequency is abnormal, the first and second rectifier switches of the rectification unit of the power supply are forced to turn on or turn off. Thereby, the first and second rectifier switches can turn on alternately, and the first and second rectifier switches are limited to within the highest and lowest working frequencies during the zero-load stage or the shutdown stage. Thus, the frequency of the synchronous rectification driver is under control, and abnormal voltage will not occur.

Abstract: A power factor correction circuit used for regulating the phase of a DC current outputted from a rectifier unit in a power supply includes an energy inductor, an output diode, a switch unit, a pulse width modulation unit, a sensing resistor, and a converter transformer. The converter transformer utilizes the DC current outputted from the rectifier unit to generate an induced current, which will pass through the two ends of the sensing resistor to produce a reference voltage, thereby the pulse width modulation unit can produce the duty cycle for the switch unit according to the reference voltage, so that the switch unit can regulate the phase of the DC current through controlling the flowing direction of the DC current.

Abstract: The present invention discloses a method for controlling transformer excitation cycles and a circuit for controlling the same, wherein the excitation cycle and the demagnetization cycle, which determine the rise and fall of the excitation current, are modified to prevent the coil from being saturated. In the present invention, a sense current is acquired from the excitation current of the transformer coil, and a demagnetization reference value is set. The sense current is used to determine whether the excitation current is lowered to the demagnetization reference value in the demagnetization cycle. A cycle modifying circuit is used to modify the duty cycle signal output by a pulse control unit until the excitation current is lowered to a preset level.

Abstract: In a multi-sectional plug rotating and positioning structure, a power connector includes a casing, a plug having a pivotal axle pivotally coupled to the casing and a rotating route, a gear disposed on the pivotal axle and driven by the pivotal axle and having a plurality of gear tooth portions, a limit plate positioned in the casing, and a latch portion extended from the limit plate and corresponding to the gear tooth portions. The latch portion of the plug is coupled to the gear tooth portion to define a limit relation in the rotating route. The plug can be rotated with respect to the casing to reduce volume and facilitate carrying the product. The gear of the pivotal axle is latched to the limit plate, so that the plug gives a multi-sectional positioning effect in the rotating route to provide hand feels for rotation and positioning.

Abstract: A transformer having a leakage inductance control structure includes a primary coil, a secondary coil formed at a selected coil ratio relative to the primary coil to transform voltage and output electric power, and a leakage inductance control coil which is wound on the secondary coil in an insulation manner according to a selected coupling efficiency and electrically connected to the primary coil. Through electromagnetic coupling of the leakage inductance control coil and the secondary coil a power control signal is output and sent to the primary coil to control leakage inductance of the primary coil.

Abstract: A plug adapter includes a holder and a plug. An adaptation ring is provided on the holder; the adaptation ring containing multiple gaps. A mounting plate from the plug is snapped into the adaptation ring and turns in a given direction. The mounting plate is secured in place by pressing a push for the plug to engage with the holder. The push may also be pressed to turn the mounting plate in an opposite direction, causing the plug to disengage from the holder to facilitate replacement of the plug with another plug of differing specification.