In the field of line commutated converters, for use in high voltage direct current (HVDC) power transmission, a line commutated converter (10) comprises a plurality of converter limbs (12A, 12B, 12C) that extend between first and second DC terminals (16, 18). Each converter limb (12A, 12B, 12C) includes first and second limb portions (22, 24) which are separated by an AC terminal (26A, 26B, 26C). The first limb portions (22) together define a first limb portion group (28) and the second limb portions (24) together define a second limb portion group (30). Each limb portion (22, 24) includes at least one switching element (36, 36 2, 36 3, 36 4, 36, 36 6) that is configured to turn on and conduct current when it is forward biased and it receives a turn on signal and to naturally turn off and no longer conduct current when it is reverse biased and the current flowing through it falls to zero. The converter (10) also includes a control unit (38) which is programmed to, in use, control successive switching of the switching elements (36, 36 2, 36 3, 36 4, 36, 36 6) whereby a first switching element (36) in the first limb portion group (28) and a second switching element (36 2) in the second limb portion group (30) and a different converter limb (12B, 12C) to the first switching element (36) connect two corresponding AC terminals (26A, 26C in series between the first and second DC terminals (16, 18). The control unit (38) is further programmed to send a third switching element (36 3) in the first limb portion group (28) a turn on signal whereby the third switching element (36 3) turns on and begins to conduct current while the current flowing through the first switching element (36) begins to fall to zero and the first switching element (36) prepares to naturally turn off, and to subsequently send a fourth switching element (36 4) in the second limb portion group (30) and a different converter limb (12A, 12C) to the third switching element (36 3) a turn on signal whereby the fourth switching element turns (36 4) on and begins to conduct current while the current flowing through the second switching element (36 2) begins to fall to zero and the second switching element (36 2) prepares to naturally turn off. The control unit (38) also checks for an abnormal current flow (56) associated with the first switching element (36) during a fini

A series connection body wherein a first backflow prevention elements, a second backflow prevention element, a first switching element and a second switching element are connected in series in this order; a reactor; a first output capacitor connected between a first end of the series connection body and a second end of the series connection body; and a second output capacitor connected between a connection point between the first switching element and the second switching element and a connection point between the first backflow prevention element and the second backflow prevention element are provided, a DC is inputted between an end of the reactor and the second end section of the series connection body, and power is supplied to a first load connected to both ends of the first output capacitor and a second load connected to both ends of the second output capacitor.

Provided is a technique for preventing a peak current during recovery while enhancing breakdown voltage. A semiconductor device includes the following: a p.sup.-type anode layer having a uniform p-type impurity concentration; an n.sup.-type layer having a distributed n-type impurity concentration; and an n.sup.+-type layer disposed with the n.sup.-type layer interposed between the n.sup.+-type layer and the p.sup.-type anode layer, the n.sup.+-type layer having an n-type impurity concentration that is higher than that of the n.sup.-type layer and is uniform. The n-type impurity concentration of the n.sup.-type layer in a portion on the p.sup.-type-anode-layer side is lower than the p-type impurity concentration of the p.sup.-type anode layer.

To enable in a circuit arrangement (8) with a transformer with center tap the voltage measurement on the secondary side simply and safely, it is provided that at least two series-connected resistors (R3, R4) are connected between the two outer connections (A1, A2) of the secondary side of the transformer (T) to form a measurement point (P) between the two resistors (R3, R4), and a voltage measurement unit (V) is provided to measure the voltage (U.sub.P) between the measurement point (P) and the second output pole (13), which corresponds to the output voltage (U.sub.A).

A power conversion device includes a semiconductor element, a temperature sensor, a sealing material sealing the semiconductor element, and a driving circuit for the semiconductor element. The temperature sensor measures the temperature of either or both of the semiconductor element and the sealing material. The driving circuit controls a voltage steepness or a voltage crest value to be applied to the semiconductor element, on the basis of temperature information measured by the temperature sensor.

An overvoltage protection circuit is provided which is connected between a rectifier circuit and a load including an input capacitor element connected to both ends of the load. The overvoltage protection circuit includes a semiconductor switch connected between the rectifier circuit and the load, and a control circuit controls the semiconductor switch. When the rectified voltage exceeds a predetermined value, the control circuit turns off the semiconductor switch, and detects a voltage potential difference between both ends of the semiconductor switch, and then, for an interval when the voltage potential difference is zero or a predetermined minute value, the control circuit generates a control voltage for turning on the semiconductor switch, and outputs the control voltage to a control terminal of the semiconductor switch. The overvoltage protection circuit includes a current change circuit that gradually changes a current flowing through the semiconductor switch.

A thyristor or triac control circuit includes a first capacitive element that is series-connected with a first diode between a first terminal and a second terminal intended to be coupled to a gate of the thyristor or triac. A second capacitive element is coupled between the second terminal and a third terminal intended to be connected to a conduction terminal of the thyristor or triac on the gate side of the thyristor or triac. A second diode is coupled between the third terminal and a node of connection of the first capacitive element and first diode.

A circuit for converting DC to AC power or AC to DC power comprises a storage capacitor, boost and buck inductors and switching elements. The switches are controlled to steer current to and from the storage capacitor to cancel DC input ripple or to provide near unity power factor AC input. The capacitor is alternately charged to high positive or negative voltages with an average DC bias near zero. The circuit is configured to deliver high-efficiency power in applications including industrial equipment, home appliances, mobility devices and electric vehicle applications.

A radar circuit for a measuring device is provided, including: a radar chip, configured to generate a radar measurement signal; an application-specific integrated circuit (ASIC); and a processor, configured to determine a measured value, the ASIC and the radar chip being separate components.

A method and a circuit for complying with specified maximum values for output parameters a power supply unit includes at least a non-floating switch converter, an output voltage control unit, a current limiter and a switch element, wherein actual values of the current and voltage outputs of the power supply unit are measured continuously, where an evaluation unit calculates actual output power values of the power supply unit from the actual measured values of the output current and voltages, and subsequently compares at least the respective actually measured values of the output current and the respective actually calculated output power values with specified maximum values such that if at least one of the specified maximum values is exceeded by an actually measured value of the output current and/or by an actually calculated output power value, a current flow in the power supply unit is then interrupted by the evaluation unit.