An overall efficient heat dissipation system for a high power density cabinet comprises a pump-driven two-phase circulation loop high-power-chip direct heat dissipation system and a cabinet air-cooling system. The cabinet air-cooling system comprises a refrigerant circulation loop and a cabinet internal air circulation loop. The refrigerant circulation loop includes a pump-driven two-phase circulation loop and a vapor compression circulation loop. The pump-driven two-phase circulation loop high-power-chip direct heat dissipation system performs fixed-point heat dissipation for main heating elements, such as CPU and GPU, in a server, and the cabinet air-cooling system performs air-cooling heat dissipation for other heating elements in the server.

The present disclosure provides materials and methods related to passive cooling systems. In particular, the present disclosure provides a condensorator heat exchanger with a single microchannel coil that integrates the evaporator and condenser into one assembly. The passive heat exchanger systems of the present disclosure provide enhanced cooling capacity and airflow in environments ranging from outdoor electronic enclosures to commercial and residential buildings.

A cooling arrangement for a rack hosting electronic equipment and at least one fan comprises first and second air-liquid heat exchangers. A first one is mounted to the rack so that heated air expelled from the rack by the fan flows therethrough. The second one is mounted to the first one so that air having flowed through the first heat exchanger flows through the second heat exchanger. Each heat exchanger comprises a frame, an inlet receiving liquid from a cold supply line, an outlet returning liquid to a hot return line, and a continuous internal conduit forming a plurality of interconnected parallel sections. The cooling arrangement is mounted to the rack so that the first and second frames are parallel and adjacent. One interconnected parallel section of the first heat exchanger nearest to its inlet is proximate one interconnected parallel section of the second heat exchanger nearest to its outlet.

In one embodiment, a switching circuit includes an electronic switch comprising one or more diodes for switching a reactance element within an electronically variable reactance element. A first power switch receives an input signal and a first voltage, and switchably connects the first voltage to a common output in response to the received input signal. A second power switch receives an input signal and a second voltage, and switchably connects the second voltage to the common output in response to the received input signal. The second voltage is opposite in polarity to the first voltage. The first power switch and the second power switch asynchronously connect the first voltage and the second voltage, respectively, to the common output, the one or more diodes of the electronic switch being switched according to the first voltage or the second voltage being connected to the common output.

An overall efficient heat dissipation system for a high power density cabinet comprises a pump-driven two-phase circulation loop high-power-chip direct heat dissipation system and a cabinet air-cooling system. The cabinet air-cooling system comprises a refrigerant circulation loop and a cabinet internal air circulation loop. The refrigerant circulation loop includes a pump-driven two-phase circulation loop and a vapor compression circulation loop. The pump-driven two-phase circulation loop high-power-chip direct heat dissipation system performs fixed-point heat dissipation for main heating elements, such as CPU and GPU, in a server, and the cabinet air-cooling system performs air-cooling heat dissipation for other heating elements in the server.

A cooling assembly for cooling server racks includes a server rack enclosure sub-assembly that includes at least one panel member defining a volume for receiving one or more server racks having a front portion and a rear portion, at least one of the panel members is a rear panel member; at least one frame member defines an opening for receiving the rear portion of the server racks to form a hot space between the rear panel member and the combination of the frame member and the rear portion of the server racks; a cooling sub-assembly disposed in thermal communication with the hot space to cool at least one server supported in the server rack and including a chassis receiving at least one heat exchange member for exchanging heat between a refrigerant fluid flowing through the heat exchange member and fluid flowing through the hot space heated by the server.

A case heat dissipation structure is provided, which includes a case, a heat exchange assembly and a fan assembly. The case has a first heat dissipation chamber and a second heat dissipation chamber that are communicated with each other, and multiple heat sources are mounted in the first heat dissipation chamber and the second heat dissipation chamber, a liquid inlet for cooling liquid to flow in and a liquid outlet for cooling liquid to flow out are provided on the case. The heat exchange assembly is mounted in the first heat dissipation chamber, the heat exchange assembly comprises a heat exchanger, which is arranged between the liquid inlet and the liquid outlet. The fan assembly is mounted in the first heat dissipation chamber or the second heat dissipation chamber, and is used for driving the air in the first heat dissipation chamber and the second heat dissipation chamber to circulate mutually in operation.

In one embodiment, an RF impedance matching circuit is disclosed. The matching circuit is coupled between a plasma chamber and an RF source. The matching circuit includes a first electronically variable capacitor (EVC) having a first variable capacitance, a terminal of the first EVC being operably coupled to the RF input, and a second EVC having a second variable capacitance, a terminal of the second EVC being operably coupled to the RF output. A control circuit determines, based on a first parameter, a first capacitance value for the first EVC and a second capacitance value for the second EVC. The control circuit then generates a control signal to alter the first and second variable capacitances accordingly. The alteration of the capacitances, while the frequency of the RF source is not altered, causes RF power reflected back to the RF source to decrease.

In one embodiment, a switching circuit includes an electronic switch comprising one or more diodes for switching a reactance element within an electronically variable reactance element. A first power switch receives an input signal and a first voltage, and switchably connects the first voltage to a common output in response to the received input signal. A second power switch receives an input signal and a second voltage, and switchably connects the second voltage to the common output in response to the received input signal. The second voltage is opposite in polarity to the first voltage. The first power switch and the second power switch asynchronously connect the first voltage and the second voltage, respectively, to the common output, the one or more diodes of the electronic switch being switched according to the first voltage or the second voltage being connected to the common output.

In one aspect, a medium voltage power converter includes a cabinet having: a power cube bay to house a plurality of power cubes, each of the plurality of power cubes adapted within a corresponding enclosure and comprising a low frequency front end stage, a DC link and a high frequency back end stage, the plurality of power cubes to couple to a high speed machine; and a plurality of first barriers adapted to isolate and direct a first flow of cooling air through one of the plurality of power cubes; and a transformer bay having at least one transformer to couple between a utility connection and the plurality of power cubes, the transformer bay including a plurality of cooling fans to cool the at least one transformer.