Hong Kong Applied Science and Technology Research Institute Company, Limited

Danting Xu

Ziyang Gao

Kun Wu

Bin Xie

Kin Lap Wong

Qingchun Li

Chengyong Li

Xuechao Liu

Yue Ma

A Switched-Mode Power Supply uses a primary winding of a transformer rather than an inductor. The secondary winding of the transformer is driven with a current generated by a negative inductance circuit. When the reverse current flows it can increase the equivalent inductance value of the primary windings. A steady-state detector activates a steady signal and closes a switch to turn on the reverse current from an op amp when the output voltage remains within predetermined limits, causing the inductance to increase thus reducing ripple during steady state. When an output transient occurs, the steady signal is deactivated and the switch opened to stop the current from flowing through the transformer secondary, reducing primary inductance to allow for current to flow faster to the output to suppress the transient. Resistor and capacitor networks around the op amp allow for tuning the inductance modulation.

Active variable inductor circuit

A power-converter module has a switching Printed Circuit Board (PCB) with power transistors that generate heat. Ground, an input power supply, and an output power supply to the power transistors connect through metal traces on the switching PCB directly to interposer heat sinks that are soldered between the switching PCB and a system PCB. The metal traces and interposer heat sinks carry both supply or ground currents and heat away from the power transistors. These power and ground currents continue from the interposer heat sinks to the system PCB through direct solder joints between the system PCB and the interposer heat sinks. An interposer PCB has a same thickness as the interposer heat sinks and carries control signals from the system PCB to the switching PCB, bypassing the interposer heat sinks. The interposer heat sinks have an interposer portion soldered between the PCBs and fins beyond the switching PCB footprint.

Power converter package with thermally enhanced interposers to cooling fins

An active filter reduces Electro-Magnetic Interference (EMI) created by current flowing through a power line. The active filter connects to the power line at a single node through a connection capacitor. A sense current flows through the connection capacitor when the power line current changes. This sense current is applied to a gain control circuit having cross-coupled PNP transistors that drive currents to both terminals of a variable capacitor. The variable capacitor converts these currents to a voltage that is injected back into the power line through the connection capacitor as an injected compensation voltage that compensates for the sensed current.

Active filter for electromagnetic interference (EMI) reduction using a single connection point and a negative impedance converter with cross-coupled transistors

A smart power hub has an AC port, a first DC port to a car battery, a second DC port to DC devices such as car instruments, and a third DC port to solar panels or another smart power hub. An AC bi-directional converter has six transistors in a B6 configuration to convert three-phase AC, acting as an interleaved totem-pole Power-Factor-Corrector for one-phase AC. A switch connects the DC bi-directional converter with either the AC bi-directional converter or the solar panels on the third DC port. A link capacitor has a DC link voltage that rises during battery charging. A DC bi-directional converter has a transformer, a primary bridge connected to the DC link voltage, and a secondary bridge of transistors connected to the first DC port. Auxiliary windings in the transformer drive a rectifier to the second DC port to power on-board DC devices. Solar DC charges the battery without AC conversion.

Smart power hub

An active filter reduces Electro-Magnetic Interference (EMI) created by current flowing through a power line. The active filter connects to the power line at a single node through a connection capacitor. A sense current flows through the connection capacitor when the power line current changes. This sense current is applied to a non-inverting input of an op amp to drive a power amplifier circuit through a filter capacitor. The power amplifier circuit increases the current drive of the op amp to charge a transfer capacitor that converts the power amplifier output current to a transfer voltage. The transfer capacitor is connected to the connection capacitor so that the transfer voltage is injected back into the power line through the connection capacitor as an injected voltage that compensates for the sensed current. Op amp gain is adjustable by variable resistors that connect to the inverting input of the op amp.

Active filter for electromagnetic interference (EMI) reduction using a single connection point and a negative impedance converter

Example embodiment is a power converter that adopt a 3D structure to increase the power density and improve thermal performance. The power converter includes a bottom substrate and at least one side substrate. Both the bottom substrate and the side substrate are rigid. Each side substrate is connected with the bottom substrate by a flexible substrate and forms an angle with the bottom substrate. The bottom substrate is further electrically connected with a plurality of surface mounting devices which are rigid. The flexible substrate provides electrical connection between the bottom substrate and the side substrate.

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Hong Kong, China

Danting Xu