Abstract: An electronic circuit breaker of a power having dual output ports has an input port, two output ports, two field effect transistors, two current detection circuits and two control circuits. The control circuit has a silicon controlled rectifier (SCR) and an activation circuit detecting if a short circuit is present at one of the output ports through one of the current detection circuits, activating the SCR to turn off a corresponding FET after the occurrence of the short circuit, and disconnecting a corresponding output port from the input port. Due to the characteristics of the SCR, the SCR, once activated, stays in an on state between its anode and cathode. After the current of the output returns to its normal state, the FET is still turned off. Accordingly, high-frequency large current arising from alternately switching between the on and off states of the FET can be avoided.

Abstract: A symmetric planar transformer having adjustable leakage inductance has a circuit board, two first bobbins mounted respectively on opposite side surfaces of the circuit board, two primary windings mounted respectively on the first bobbins, two secondary windings disposed respectively between the circuit board and the first bobbins, two second bobbins disposed respectively between adjacent first bobbins and primary windings, two pad sets disposed respectively between adjacent first bobbins and second bobbins, and a magnetic core assembly mounted through the circuit board, the first and second bobbins, the secondary and primary windings and the pad sets. Adjusting the numbers of the at least one pad of each pad set also adjusts distances between the primary and secondary windings to allow the secondary windings to have the same leakage. Thus, a balanced electric current is induced.

Abstract: A transformer has two magnetic cores, at least one primary winding unit mounted in the magnetic cores, at least one secondary winding unit mounted in the magnetic cores and two rectifying circuit boards externally mounted beside the magnetic cores. An AC voltage output from the secondary winding unit is transmitted to and rectified by the rectifying circuit board. Therefore, the size of the transformer is compact, and heat energy generated by electronic elements mounted on the rectifying circuit board is effectively dissipated to maintain normal operation of the transformer. Further, since the transmission path from the secondary winding unit to the rectifying circuit board is short, energy loss is reasonably reduced when the transformer is operated under a high frequency situation or a larger current mode.

Abstract: A method for controlling soft start of a power supply performs soft start under an open loop control mode after the power supply is started, enters a switching control mode when output voltage of the power supply reaches a reference value, starts to convert the output voltage of the power supply into digital data using an analog-to-digital converter for determining if the power supply is switched to a closed loop control mode and the output voltage is adjusted under the switching control mode. Using the foregoing technique can enhance the bit length utilization rate of the analog-to-digital converter, ensure a smooth waveform of the output voltage and suppress maximum excess or minimum deficiency or a transient response at the switching control mode.

Abstract: A power factor correction circuit and a control method thereof uses a power factor controller to generate a compensation current signal according to an input voltage of an AC-DC conversion circuit and a filter capacitor value. An estimation current signal is generated by summing up the compensation current signal and an inductor current signal of the AC-DC conversion circuit. And then, a pulse width modulation signal is outputted to the AC-DC conversion circuit according to the estimation current signal. The filter capacitor value is chosen from a capacitor value of a capacitor connected to the AC power source, an input capacitor value of the AC-DC conversion circuit, or sum of both the capacitor values. Therefore the estimation current signal approaches an input current signal of the power factor correction circuit to increase the power factor at the input terminals of the power factor correction circuit and decrease a harmonic distortion.

Abstract: A power supply for a negative voltage load has a switch-mode power unit, a monitoring unit, a first auxiliary power unit and a second auxiliary power unit. The switch-mode power unit has a rectifying circuit, a power factor correction circuit, a DC to DC power circuit. The first auxiliary power unit is connected to output terminals of the power factor correction circuit and converts DC power to a first DC power for driving the monitoring unit. The second auxiliary power unit is connected to the negative voltage load in parallel and converts negative power from the negative voltage load to a second DC power for driving the monitoring unit when AC power is interrupted. Since the first and the second auxiliary power unit do not work at the same time, the power supply can effectively enhances the conversion efficiency of the power supply.

Abstract: A burst mode resonant power converter with high conversion efficiency has a rectifier, a power factor correction circuit, a resonant circuit, a controller, and a burst mode triggering unit. The maximum frequency switching end of the controller is connected to a maximum frequency variable circuit. When the load is medium or heavy, the maximum frequency variable circuit increases the maximum switch frequency of the controller. When the load is in the no-load or the light conditions, it reduces the maximum switch frequency thereof. Therefore, the controller reduces the number of times that the resonant circuit switches the bridge switch circuit. The conduction cycle of the 50% pulse signal output to the bridge switch circuit becomes longer. Larger energy can be transmitted at a time to the secondary coil of the transformer. This increases the overall efficiency.

Abstract: A universal input switching power supply has a signal detecting unit, two DC converting units and a physical wiring and controlling unit. The DC converting units are respectively adapted to couple to an AC power source to convert the AC power source to two first DC power sources and changes a voltage of each of the first power sources according to different voltage of the AC power source. The physical wiring and controlling unit is connected to the outputs of the DC converting units and the signal detecting unit and automatically connects the outputs of the PFC circuits in parallel if a high line voltage range of the AC power source is coupled to the full bridge rectifier. On the contrary, the physical wiring and controlling unit automatically connects the outputs of the PFC circuits in serial. Accordingly, the universal input switching power supply has good transmitting efficiency at different AC power source conditions.

Abstract: A powerline network system having data relay function includes a plurality of power monitoring zones mutually connected with a powerline network and at least one repeater. Each of the power monitoring zones has at least one power monitoring device. The repeater is connected with each power monitoring device in two adjacent power monitoring zones through powerlines and has a first and a second relay units. The first and second relay units employ two different sets of transmitting and receiving bands to fetch data contained in powerline signals transmitted by each power monitor in adjacent power monitoring zones. The data are received by a relay unit are modulated with different transmitting band and then transmitted to powerlines of another power monitoring zone. The repeaters are not required to be serially connected to the powerlines, and incorrect data read can be also eliminated.

Abstract: A power supply having a two-way DC to DC converter has an AC to DC converter and a two-way DC to DC converter. When an AC power is input to the AC to DC converter, the AC to DC converter transforms the AC power to a middle level DC power and the two-way DC to DC converter transforms the middle level DC power to a low level DC power. When the AC power is unavailable and the two-way DC to DC converter obtains an external DC power, the two-way DC to DC converter transforms the external DC power to the middle level DC power. Therefore, if the power supply obtains the external DC power, the power supply can still output the middle level DC power even the AC power is unavailable.

Abstract: A voltage equalizer is applied to balance voltages among multiple battery units that are connected in series as a battery assembly. The voltage equalizer has a transformer, a switch and a controller. The transformer has a primary winding connected to the battery assembly and the controller through the switch, and further has multiple secondary windings connected to the battery units respectively. When the switch is alternately turned on and off, the transformer draws energy from the battery units with the higher voltage and couples the energy to the secondary windings to charge the battery unit with the lower voltage for balancing the voltages of the battery units.

Abstract: A universal input switching power supply has the rectifier, a signal detecting unit detecting a voltage of an external AC power and outputting a detecting signal, a PFC circuit converts a first DC power from the rectifier to a second DC power with different voltage according to the detecting signal; and a parallel and serial type DC to DC converter converting the second DC power with different voltage to a constant voltage of the third DC power. The parallel and serial type DC to DC converter has a transformer having a primary and secondary coils and physically changes a turn ratio of the primary and secondary coils of a transformer thereof according to a voltage ratio of the second DC power and the third DC power. Accordingly, the universal input switching power supply has good transforming efficiency at different AC power source conditions.

Abstract: A symmetric planar transformer having adjustable leakage inductance has a circuit board, two first bobbins mounted respectively on opposite side surfaces of the circuit board, two primary windings mounted respectively on the first bobbins, two secondary windings disposed respectively between the circuit board and the first bobbins, two second bobbins disposed respectively between adjacent first bobbins and primary windings, two pad sets disposed respectively between adjacent first bobbins and second bobbins, and a magnetic core assembly mounted through the circuit board, the first and second bobbins, the secondary and primary windings and the pad sets. Adjusting the numbers of the at least one pad of each pad set also adjusts distances between the primary and secondary windings to allow the secondary windings to have the same leakage. Thus, a balanced electric current is induced.

Abstract: A full bridge phase shifted power supply with synchronous rectification and current doubler and method for dynamically adjusting delay parameters thereof mainly have multiple delay parameter combinations respectively varying with multiple loads and embedded in a controller of the power supply. The delay parameter combinations serve to determine driving waveforms of two rectification switches of a synchronous rectification and current doubler circuit of the power supply. When the load of the power supply varies, the controller dynamically performs a corresponding delay parameter combination so as to vary the driving waveforms of the rectification switches of the synchronous rectification and current doubler circuit and enhance the operating efficiency of the power supply.

Abstract: An AC to DC power converter with hold up time function has a charging switch and a mode switch. The charging switch is connected between an output capacitor of a PFC controlling circuit and an energy-storage capacitor. The mode switch is connected between the energy-storage capacitor and an input of the PFC controlling circuit. The charging and mode switches are controlled by a PFC controller. When AC power is normal, the charging switch turns on and mode switch turns off. Meanwhile, the energy-storage capacitor and the output capacitor are connected in parallel to store energy in the energy-storage capacitor. When the AC power source is interrupted, the charging switch turns off and mode switch turns on. Therefore, the energy-storage capacitor is disconnected from the output capacitor. The PFC circuit obtains power from the energy-storage capacitor and continuous to supply an output voltage for a while.

Abstract: A packaged heat dissipating assembly for an intermediate bus converter (IBC) has a frame being mounted on and around the IBC and a heat sink being mounted on the frame. The packaged heat dissipating assembly is easily detached from the IBC. Therefore, a broken bus converter module (BCM) or heat sink is easily replaced separately. Consequently, heat dissipating designs and maintenance of a server or communication equipment is facilitated and maintenance costs of the IBC and the server or communication equipment are lowered.

Abstract: An airflow guiding and heat dissipating assembly is mounted in an electronic device and has a base and at least one baffle being mounted on the base. Multiple electronic components are mounted on the base and are arranged in a line. Airflow flows along one electronic component upstream, past the baffle and then over the other electronic component downstream to take away heat from the electronic component. The baffle prevents the airflow from becoming turbulent and, therefore, temperatures of the electronic component are lowered efficiently.

Abstract: A heat dissipation device has a main controller and a fan module having a motor coil, a connection interface, a PWM driving circuit and a fan monitor chip. The connection interface has a control pin, an error report pin, a power supply pin and a ground pin. The control pin receiving a control signal. The PWM driving circuit adjusts current magnitude and current direction of the motor coil to drive the fan module. The fan monitor chip is connected to the connection interface and the PWM driving circuit, receives the control signal, generates and sends PWM signals to the PWM driving circuit according to the control signal and sends an acknowledgement signal via the control pin after receiving the control signal. The main controller can check if the control signal is correctly received based on the acknowledge signal.

Abstract: A slope compensation method and circuit for a peak current control mode power converter circuit is provided. Since the power converter circuit has a synchronous signal of a driven signal of enabling the first primary switch and the second primary switch, a triangular wave signal is generated. The driven signals of the first and second primary switches determine the ramp up time of the triangular wave signal. The triangular wave signal is added to one of the output DC voltage feedback signal of the corresponding power converter circuit that are used to compare with a current peak value of the voltage feedback signals. Therefore, a high level triangular wave DC voltage feedback signal that is higher than the DC voltage feedback signal is formed, and the switching noises do not effect comparing result of a PWM controller of the power converter circuit.

Abstract: The present invention discloses a compact server power supply having high power density has a casing, a main printed circuit board, a sub-printed circuit board, a power supplying circuit, a power output terminal set and a fan. The power supplying circuit has a primary side circuit unit, a transformer and a secondary side circuit unit. Electric elements of the primary and secondary side circuit units and the transformer are soldered on the main printed circuit board except parts of the electric elements of the secondary side circuit unit are soldered on the sub-printed circuit board. The sub-printed circuit board is vertically mounted and soldered on the main printed circuit board, so the length of the main printed circuit board is shortened to implement the server power supply having a compact size and high power density.