A synchronous rectification power supply controls driving of a switching unit in such a manner as to start the driving in response to rising of an output voltage at a secondary side of a transformer and to stop the driving after a predetermined time passed.

Power supply and image forming apparatus

A two-stage power converter architecture including an isolation transformer and rectification of the isolation transformer output by an LLC resonant circuit and methodology for operating the same feeds an output voltage back to a circuit for generating waveforms for controlling a totem pole circuit to provide output voltage regulation as well as rectification of AC input voltage. The circuit for controlling the totem pole circuit may also be responsive to the AC input power waveform to provide power factor correction (PFC), in which case, the feedback signal provides additional pulse width modulation of the PFC signals. Bus capacitor size may also be reduced by injecting harmonics of the AC input waveform into the feedback signal which also serves to substantially maintain efficiency of the (preferably LLC) resonant second stage.

Universal system structure for low power adapters

There are provided a power module and a multi power supply apparatus having the same. The multi power supply apparatus includes a plurality of power modules connected in parallel with each other and supplying a preset power, each power module including: a DC/DC converting unit converting an input power into a preset DC power; an output controlling unit switched on or switched off according to a difference between a voltage level of the DC power of the DC/DC converting unit and a voltage level applied to a load end to control an output of the DC power; and a controlling unit starting a soft start operation of the DC/DC converting unit during a hot swap in which the power module is replaced and stopping the soft start operation of the DC/DC converting unit when the output controlling unit is switched on.

Power module and multi power supply apparatus having the same

A network communication device is disclosed. The network communication device includes a circuit board, a network connector, a network chip and a plurality of network magnetic assemblies. The network connector, the network chip and the network magnetic assemblies are disposed on the circuit board. The network magnetic assemblies are electrically connected with the network connector and the network chip, respectively. Each of the network magnetic assemblies includes an Ethernet transformer and at least one inductor. The Ethernet transformer is electrically connected in series with the inductor via a conductive trace of the circuit board. Any two adjacent Ethernet transformers are separately arranged with a gap having a second specific length.

Network communication device

The invention provides a direct-current filter inductor and a manufacturing method thereof. The direct-current filter inductor comprises a magnetic core, at least one first winding and at least one second winding. The magnetic core is provided with at least one air gap. The first winding and the second winding are connected with each other in parallel and are respectively coiled on the magnetic core. The difference value between the inductance value of the first winding and the mutual inductance value of the first winding and the second winding is smaller than the difference value between the inductance value of the second winding and the mutual inductance value of the second winding. The direct current resistance of the first winding is larger than that of the second winding. The first winding is closer to the air gap than the second winding. The direct-current filter inductor is formed by two independent inductive windings which are coiled on the same magnetic column and are connected with each other in parallel, achieves separating of alternate current and direct current of the windings through coupling, and is capable of reducing alternating current loss of the windings, improving magnetic flux distribution near the air gap, and reducing influence of electromagnetic interference.

Direct-current filter inductor and manufacturing method thereof

Disclosed is a power converter including a switching circuit; a transformer having a primary winding connected to the switching circuit and a secondary winding; a main control circuit connected to the switching circuit for outputting a main control signal to manipulate the switching circuit; at least one synchronous rectifier connected to the secondary winding; at least one current transformer connected to the synchronous rectifier for outputting a detecting signal according to a current flowing through the synchronous rectifier; and at least one synchronous rectification control circuit connected to a control terminal of the synchronous rectifier, the current transformer, and a control terminal of the switching circuit for receiving the detecting signal and the main control signal for manipulating the synchronous rectifier. In case that the main control circuit manipulates the switching circuit to turn on, the synchronous rectification control circuit manipulates the synchronous rectifier to turn on, and thereby allowing the synchronous rectification control circuit to manipulate the synchronous rectifier to turn off according to the detecting signal.

Power converter having synchronous rectifier and control method of synchronous rectifier

A power module includes a first bobbin, a primary winding coil, a circuit board assembly and a first magnetic core assembly. The primary winding coil is wound around the first bobbin. The circuit board assembly includes a printed circuit board, a second winding structure, at least one current-sensing element, a rectifier circuit and an electrical connector. The second winding structure has an output terminal. The current-sensing element includes a first conductor. The first conductor is a conductive sheet. A first end of the first conductor is in contact with the output terminal of the second winding structure. A second end of the first conductor is connected to the rectifier circuit. The primary winding coil is aligned with the second winding structure of the circuit board assembly and arranged within the first magnetic core assembly. The primary winding coil and the electrical connector are electrically connected with a system board.

Power module and circuit board assembly thereof

The invention discloses a power supply converter with a synchronous rectifier and a control method for the synchronous rectifier. The power supply converter comprises a switching circuit, a transformer, a main control circuit, the synchronous rectifier, a current transformer and a synchronous rectifying control circuit, wherein the transformer is provided with a primary winding and a secondary winding, and the primary winding is connected with the switching circuit; the main control circuit is connected with the switching circuit to control the operation of the switching circuit; the synchronous rectifier is connected in series with the secondary winding; the current transformer is connected in series with the synchronous rectifier and outputs a detection signal according to the current flowing through the synchronous rectifier; the synchronous rectifying control circuit is connected with the control end of the synchronous rectifier, the current transformer and the control end of the switching circuit to receive the detection signal and a main control signal and used for controlling the operation of the synchronous rectifier; and when the main control circuit controls the switching circuit to be conducted, the synchronous rectifying control circuit controls the synchronous rectifier to be conducted, and the synchronous rectifying control circuit controls stoppage of the synchronous rectifier according to the detection signal. The synchronous rectifier is not easily burnt, and the integral efficiency is relatively promoted.

Power supply converter with synchronous rectifier and control method for synchronous rectifier

A power module and the printed circuit board assembly thereof are disclosed. The power module is disposed on a system circuit board and comprises a first bobbin, a printed circuit board assembly, and a first magnetic core assembly. The first bobbin has a primary winding structure disposed thereon. The printed circuit board assembly comprises a printed circuit board and a secondary winding structure, a current sensor device, a rectifying circuit, and a connector disposed on the printed circuit board. The secondary winding structure comprises an output terminal. The current sensor device comprises a first conductive structure being a conductive plate and directly contact with the output terminal of the secondary winding structure via the first end thereof. The second end of the current sensor device is coupled to the rectifying circuit. The primary winding structure of the first bobbin and the secondary winding structure of the printed circuit board assembly are disposed in the first magnetic core assembly and corresponded to each other, and the primary winding structure and the connector of the printed circuit board assembly are electrically connected to the system circuit board.

Power module and printed circuit board assembly thereof

A power converter is disclosed. The power converter includes a switch circuit, a transformer, a main control circuit, a synchronizing rectifier, a current transformer and a synchronizing rectifier control circuit. The transformer has a primary winding and a secondary winding, wherein the primary winding is connected with the switch circuit. The main control circuit is connected with the switch circuit to control the operation of the switch circuit. The synchronizing rectifier is connected in series with the secondary winding. The current transformer is connected in series with the synchronizing rectifier and outputs a detecting signal according to the current flowing through the synchronizing rectifier. The synchronizing rectifier control circuit in connected with a control terminal of the synchronizing rectifier, the current transformer and a control circuit of the switch circuit to receive the detecting signal and a main control signal for controlling the operation of the synchronizing rectifier. When the switch circuit is conducted under the control of the main control circuit, the synchronizing rectifier is conducted or shut off under the control of the synchronizing rectifier control circuit, wherein the synchronizing rectifier is shut off according to the detecting signal.

Jinfa Zhang

Papers

Power converter having synchronous rectifier and control method of synchronous rectifier

Power module and circuit board assembly thereof

Power supply converter with synchronous rectifier and control method for synchronous rectifier

Power module and printed circuit board assembly thereof

Power converter having synchronizing rectifier and control method of synchronizing rectifier