A balun circuit includes a first transformer comprising a first inductor and a second inductor, the first inductor having an electrical value different than the second inductor, a second transformer comprising a third inductor and a fourth inductor, the third inductor having an electrical value different than the fourth inductor, the first inductor connected to a positive terminal of a balanced port, the third inductor connected to a negative terminal of the balanced port, the second inductor connected to an unbalanced port and the fourth inductor connected to a node.

A wind turbine generator 1 supplies three-phase a.c. current of variable voltage and variable frequency to two pairs of rectifiers 4a, 4b and 4c, 4d which generate respective d.c. outputs connected to positive, negative and neutral d.c. conductors 6, 7, 8. The outputs from each pair of rectifiers are connected together, and the outputs from the two pairs are connected in series to create a high-voltage d.c. output. Inverters 10a, 10b, 10c, 10d then convert the d.c. power to a.c. at a fixed frequency and voltage suitable for connection to the mains grid. To reduce the effect of common-mode noise, a capacitor is connected between the 1 neutral conductor 7 and earth, and a respective filter circuit 30 is connected between each of the a.c. outputs of the inverters 10a, 10b, 10c, 10d and earth. To reduce the effect of voltage surges during lightning, a surge protection device is also connected between the neutral d.c. conductor 7 and earth. Any imbalance in the current in the positive and negative conductors 6, 8 is compensated by detecting the presence of current flowing in the neutral conductor 7. Power supplied to auxiliary circuits from the output of one of the inverters, e.g. 10a, of the wind turbine is measured, and any resulting imbalance between the current in the positive and negative conductors is compensated. In the event of an earth-leakage fault in the conductors connecting the a.c. outputs of the inverters to the grid, when isolated, isolation detection relays 25 are provided.

An electronic device and a method for filtering common mode disturbances from a power electronic device are disclosed. In an embodiment the device includes a first capacitor coupled in series to a first one-way conductor, the first one-way conductor allowing current flow in one direction, wherein the first one-way conductor and the first capacitor are coupled between a load node and a reference potential and a second capacitor coupled in series to a second one-way conductor, the second one-way conductor allowing current flow in an opposite direction, wherein the second one-way conductor and the second capacitor are coupled between the load node and the reference potential. The device further includes a third capacitor being coupled between the load node and the reference potential, a first switch bypassing the first one-way conductor and a second switch bypassing the second one-way conductor.

Aspects of the invention provide for an electrostatic protection device for protecting an input port of an electronic circuit. The electrostatic protection device includes a stacked coil assembly with four ports. The electrostatic protection device further includes a human body model ESD protection circuit, a charge device model ESD protection circuit, and an impedance matching circuit. The human body model ESD protection circuit, the charge device model ESD protection circuit, and the impedance matching circuit are connected to separate ports selected from the four ports.

A filter component having an ESD protection function that includes a mounting inductor component and a base board. An ESD protection element and a capacitor are formed in the base board, which includes a semiconductor substrate, and front and back rewiring layers. First and second mounting component connection terminal conductors to which the mounting inductor component is connected are formed on an outer surface of the front rewiring layer. Moreover, a first, second and third external connection terminal conductors are formed on an outer surface of the back rewiring layer. The ESD protection element is formed in the semiconductor substrate and the capacitor is formed in one of the front rewiring layer or the back rewiring layer.

A filter that includes a series circuit of a first Zener diode and a second Zener diode, a third Zener diode connected between a node and ground, and a third inductor. A first series resonant circuit is formed by a parasitic capacitance of the first Zener diode, a parasitic capacitance of the third Zener diode, and the third inductor, and a second series resonant circuit is formed by a parasitic capacitance of the second Zener diode, the parasitic capacitance of the third Zener diode, and the third inductor. Moreover, the parasitic capacitances of the first Zener diode and the second Zener diode are substantially equal, and the parasitic capacitance of the third Zener diode is larger than the parasitic capacitance of each of the first Zener diode and the second Zener diode.

An electronic component having a multilayer body that includes a plurality of insulating layers that are stacked on top of one another; a primary coil and a secondary coil that are arranged inside the multilayer body in a stacking direction of the multilayer body; a first ground electrode and a second ground electrode that are provided in the multilayer body and between which the primary coil and the secondary coil are interposed in the stacking direction; and a ground terminal that is connected to the first ground electrode and the second ground electrode. A capacitance is generated between the first ground electrode and the primary coil or the secondary coil and a capacitance is generated between the second ground electrode and the primary coil or the secondary coil.

A composite electronic component includes a composite body in which a common mode filter and a multilayer ceramic capacitor array are coupled to each other, the common mode filter including a first body having a common mode choke coil, and the multilayer ceramic capacitor array including a second body in which a plurality of dielectric layers are stacked.

A DC/DC electrical configuration for operating over a large span of input voltages. The electrical configuration converter including a pre-filter, a voltage limiter; a first DC/DC converter; a second DC/DC converter; a step-down transformer; and a rectifier filter. The DC-DC electrical configuration safely operates in a presence of an input voltage that varies in magnitude.

A filter can be used in circuit. The filter includes a first stage including a first resonator configured to oscillate at a first fundamental frequency, a second resonator configured to oscillate at a second fundamental frequency, and a first nonlinear coupler for the first resonator and the second resonator. The second fundamental frequency being one half of the first fundamental frequency. The filter also includes a second stage including a third resonator, a fourth resonator, and a second nonlinear coupler for the third resonator and the fourth resonator.