Mitsubishi Electric Corporation

Masaki Takata

Yoshihiro Taniguchi

Yoshiaki Koizumi

Shinsaku Kusube

Shigeo Takata

Satoshi Endo

Masahiro Ishihara

Shuhei Mizutani

Keiji Harada

Provided are a heat sink capable of suppressing overcooling of an electronic component which should not be overcooled and highly efficiently cooling only an electronic component which should be cooled, and a circuit device including the same. A heat sink includes a pipe and a cooling block. At least one projection is formed in the cooling block. The pipe is in contact with the projection. The pipe is arranged with a spacing from a portion of the cooling block other than the projection.

Heat sink and circuit device

A voltage/current verifier computes, for each phase, a phase difference between phase voltage and phase current from the phase of phase voltage and the phase of phase current computed for each phase by a phase acquirer, and determines conformity if all of the computed phase differences are within a preset range. A current/current verifier computes phase differences between phase currents from the phase of phase current computed for each phase by the phase acquirer, and determines conformity if all of the computed phase differences are less than 180&#xb0;. A reporting device reports that a current transformer is incorrectly placed on a power line unless both the voltage/current verifier and the current/current verifier do not determine conformity.

Device, method and program for determining misplacement of a current transformer on a power line

A three-phase AC to DC converter includes a three-phase AC power supply, a three-phase rectifier bridge circuit that is connected to the three-phase AC power supply and includes rectifying devices which are connected in a bridge configuration, a three-phase full-bridge circuit that includes two serially-connected switching devices for each of three phases, the two serially-connected switching devices being connected at an output side of the three-phase rectifier bridge circuit, and includes reverse blocking diodes which are connected in parallel to the respective switching devices, a reactor that connects the three-phase full-bridge circuit to the three-phase AC power supply, a smoothing capacitor connected to an output side of the three-phase full-bridge circuit, DC voltage detection means that detects an output voltage, power supply phase detection means that detects a power supply phase of the three-phase AC power supply, and pulse width modulator that outputs PWM signals which control the switching devices.

Three-phase AC to DC converter and air conditioning apparatus using three-phase AC to DC converter

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Tokyo, Japan

Masaki Takata