A safety device for an automotive EMI filter that is connected in series with a filtering capacitor. The safety device has normally a low impedance and does not alter the functioning of the filter, but it is configured to present an increased inductance in the event of a discharge. The device reduces the discharge current that can be accidentally conducted through a human body.

Disclosed herein is a common mode filter that includes a winding core part and first and second wires wound in a same direction around the winding core part. The first and second wires constitute a first winding block on one endmost side in an axial direction of the winding core part, a second winding block on other endmost side in the axial direction of the winding core part, and a third winding block positioned between the first and second winding blocks. The second winding block is a winding block at an odd-numbered position counted from the first winding block. The first and second wires cross each other in an area between the first and third winding blocks and in an area between the second and third winding blocks.

A common mode choke coil is configured in which end portions of first and second wires are connected to first and second terminal electrodes, end portions of third and fourth wires are connected to third and fourth terminal electrodes, and at least a part of each of the first, third, fourth and second wires is wound around a winding core portion to form first, second, third and fourth layers. Also, a common mode choke coil is configured in which end portions of first and second wires are connected to first and second terminal electrodes, end portions of a third wire are connected to third and fourth terminal electrodes, and at least a part of each of the first, third, and second wires is wound around a winding core portion to form first, second, and third layers.

An LC filter arrangement includes a filter capacitor that connects the first output terminal to the second output terminal, a magnetic core, and a choke having a plurality of turns surrounding the magnetic core, and a first choke terminal and a second choke terminal. Each of the turns is formed by a separate conductor segment, at least partially surrounding the magnetic core. The LC filter arrangement is mounted on a circuit board and is electrically connected to a conductor track of the circuit board.

The disclosure describes techniques to filter unwanted noise from feedback signals of an electrical machine. An electrical machine may receive AC power from an inverter and circuitry in the inverter may cause noise on the AC power signals to the electrical machine. The noise may couple to sensors for the electrical machine and cause noise in the sensor output signals. The sensor output signals may provide feedback for a closed loop control system for the electrical machine and noise may impact the closed loop operation. Also, the noise in the feedback signals may cause electromagnetic compatibility (EMC) issues, either by direct radiated emissions or by coupling to other circuits in the vehicle wiring harness as the feedback signals travel from the electrical machine. The techniques of this disclosure may include filter circuitry located near or inside the electrical machine that filters out the unwanted noise in the feedback signals.

The invention discloses a power noise suppression circuit applied to a power system. The power noise suppression circuit comprises at least one power noise to heat converter and at least one anti-power noise transmitted unit. When a power noise within a specific frequency band enters the power noise suppression circuit, the power noise to heat converter converts the power noise to a thermal energy, and the anti-power noise transmitted unit reflects the power noise within the specific frequency band to the power noise to heat converter. Accordingly, the power noise within the specific frequency band can be suppressed and absorbed in the power noise suppression circuit, so as to maintain the stability of the power system.

A device includes an EMC (electromagnetic compatibility) filter, a frequency converter coupled to the EMC filter, and a motor coupled to the frequency converter via a motor cable. A leakage current compensator includes a leakage current detector and a compensation current generator configured to generate a compensation current that is directed against the leakage current and is overlaid on the leakage current in such a way that the leakage current is reduced.

A common mode filter for reducing differential mode signal converting to common mode signal comprising: a core-cylinder, a first coil, and a second coil; wherein two ends of the core-cylinder respectively extend and set with a first flange and a second flange; wherein m.sub.1, m.sub.2, and m.sub.3 turns and n.sub.1, n.sub.2, and n.sub.3 turns are respectively and sequentially wound and set on the first winding portion, the second winding portion, and the third winding portion of the first winding area, the second winding area, and the third winding area of the first coil and the second coil. Therefore, the present invention can effectively reduce the mode conversion characteristic (Scd), and can also improve the noise reduction performance of the product; thereby greatly upgrading the practicality of the present invention; and the present invention has a simple process, therefore the product yield can be further upgraded to achieve the effect.

Radio frequency filtering circuitry blocks certain frequencies in an outgoing signal so that the signal may be transmitted over a desired frequency. The radio frequency filtering circuitry includes a first inductor having a first coil and a second inductor coupled to and disposed within the first coil. The second inductor has a second coil and a third coil symmetrical to the second coil. When current is applied to the radio frequency filtering circuitry, the current in the second coil causes a first induced current in the first coil and the current in the third coil causes a second induced current in the first coil, wherein the second induced current is approximately equal in magnitude and opposite in direction to the first induced current. As such, the second induced current may compensate for the first induced current.

An electric compressor includes a compression part, an electric motor, an inverter device, and a housing. The inverter device includes an inverter circuit, a noise reduction unit, and a circuit board. The noise reduction unit includes a common mode choke coil and a smoothing capacitor. The common mode choke coil includes an annular core, a pair of winding wires, and an annular electrical conductor. The electrical conductor is split into a first metal plate and a second metal plate in a circumferential direction. The first metal plate is thermally coupled to the housing. The second metal plate is electrically connected to the first metal plate. An electrical resistance value of the first metal plate is larger than that of the second metal plate.