69results about How to "Suppress radiated noise" patented technology

A multilayered printed circuit board includes a first surface layer that includes a semiconductor integrated circuit, a second surface layer that includes a bypass capacitor and that is opposite to the first surface layer, a main power supply wiring layer, and a ground layer between the first and second surface layers. In the multilayered printed circuit board, one terminal of the bypass capacitor is connected to a midpoint of a wiring path from the main power supply wiring layer to a power supply terminal of the semiconductor integrated circuit, and an impedance of a first wiring path from the main power supply wiring layer to the terminal of the bypass capacitor is higher than an impedance of a second wiring path from the terminal of the bypass capacitor to the power supply terminal of the semiconductor integrated circuit.

A multilayered printed circuit board includes a first surface layer that includes a semiconductor integrated circuit, a second surface layer that includes a bypass capacitor and that is opposite to the first surface layer, a main power supply wiring layer, and a ground layer between the first and second surface layers. In the multilayered printed circuit board, one terminal of the bypass capacitor is connected to a midpoint of a wiring path from the main power supply wiring layer to a power supply terminal of the semiconductor integrated circuit, and an impedance of a first wiring path from the main power supply wiring layer to the terminal of the bypass capacitor is higher than an impedance of a second wiring path from the terminal of the bypass capacitor to the power supply terminal of the semiconductor integrated circuit.

An engine starting device for controlling an engine start of a vehicle by driving a starter relay of the vehicle with a battery of the vehicle as a power supply has a control processing unit and a step-up circuit for stepping up the output of the battery and outputting a drive voltage for driving the control processing unit and the starter relay. The control processing unit has a function of performing an engine start control of applying the drive voltage to the starter relay to activate the starter relay in time of the engine start at which an engine starting condition is satisfied The control processing unit performs a control function on the step-up circuit to activate the step-up circuit so that the drive voltage does not become lower than a minimum operation voltage of the starter relay in a predetermined period necessary to start the engine in time of the engine start, and activate the step-up circuit so that the drive voltage does not become lower than a first voltage value higher than a minimum operation voltage of the control processing unit and lower than the minimum operation voltage of the starter relay when not in the predetermined period.

At least one of a feedback path and a feed path is divided into two paths, and the divided feedback path and the feed path for feeding a signal form a twisted pattern to suppress radiation noise of a high frequency by a twisted pair effect. The other divided feedback path decreases a resistance value of a direct current component and decreases a whole direct current resistance to feed a sufficient current to the path.

A printed wiring board, comprising a signal plane having a baseband block for processing a baseband signal and a high-frequency block for processing a high-frequency signal which is obtained by converting the baseband signal, and a ground plane opposing to the signal plane. The baseband block and the high-frequency block are connected through a transmission line for transmitting a signal of a specific frequency region. The ground plane is provided with a first ground portion and a second ground portion, the first ground portion being provided at an area opposing to the baseband block, the second ground portion being provided at an area opposing to the high-frequency block. The first ground portion and the second ground portion are coupled to each other through a coupling portion provided therebetween which has a low impedance with respect to the signal of the specific frequency region.

A signal transmitting lead 105 is provided on an electrically insulating layer 103. Auxiliary leads 104A and 104B are provided while the auxiliary leads 104A and 104B are not in electrical contact with the signal transmitting lead 105. At least a part of the auxiliary leads 104A and 104B is covered with an electromagnetic shielding layer 106. Consequently, radiant noise from the inside or the outside of a printed wiring board can be suppressed without degrading characteristics of a signal which is transmitted through the signal transmitting lead 105.

According to the invention, information processing equipment using a flexible printed-circuit board which does not lose bendability with repeated opening and closing of a display unit, and which suppresses radiation noise from signal wiring is provided. In the configuration of the invention, a first cover film is formed to cover a wiring layer on a first surface of a base film, and a second cover film is formed to cover a wiring layer on a second surface of the base film. Portions of the second cover film and the underlying wiring layer on the second surface in the loop formation region are discontinuously removed in the inward-bending area of the loop, and the base film is exposed in the removed parts. The wiring layer underneath the remaining second cover film, which is not removed, and the wiring layer on the first surface of the base film are electrically connected via through holes penetrating the base film.

A flat cable (301) is arranged in the direction of the reciprocating movement of a carriage (122), and inputs a synchronization signal to a substrate mounted on the carriage (122). When the flat cable (301) undergoes bending deformation in response to the reciprocating movement of the carriage (122) and portions of the flat cable (301) oppose one other as a result of the bending deformation, a conductive plate (311) is supported by a case (331) while interposed between the opposing portions of the flat cable (301). Elastic members (312) electrically connect the conductive plate (311) and a grounding member (321), and have a substantial inductance component which absorbs vibration generated in an image formation unit (140) or an image reading unit (120).

A motor driving system includes an AC power supply 1, an AC reactor 2, a power converter 3 and a motor 4. A microsurge suppressor 5 is inserted on a power supply line from the power converter 3 to the motor 4 and the similar microsurge suppressor 6 is inserted on a power supply line from the AC reactor 2 to the power converter 3. The microsurge suppressor 5 includes a multi-layer printed wiring board having two terminals connected to the power converter 3 and the motor 4 and a capacitor for bypassing a surge, and the terminal 4 on the side of the motor of the multi-layer printed wiring board is directly connected to a terminal of the motor 4. The capacitor for bypassing a surge is connected between the terminal of the motor 4 and the end on the side of a second terminal of second wiring.

A connector is mateable with and removable from a mating connector, which has an optical connector, along a mating direction. The connector is provided with a receptacle to be attached to a case and an adapter to be mounted on a circuit board located in the case. The adapter has an inner module to be connected to the optical connector and a cage which accommodates the inner module at least in part. One of the receptacle and the cage is provided with a contact portion which is in contact with a remaining one of the receptacle and the cage. The receptacle and the cage are electrically connected to each other through the contact portion without direct fixation between the receptacle and the cage.

To speed up the communication between the indoor unit and outdoor unit of an air conditioner and suppress the radiant noise by the communication. In the separate type air conditioner comprising the indoor unit 1 having an indoor blower 19, a control system means (including a microcomputer 7, a decoding circuit 9 and a modulating driver 12) and a temperature detection means 18; and the outdoor unit 2 having an outdoor blower 35, a refrigerant compressor 36, a control system means, and a temperature detection means 21, two connecting cables 3 and 4 for supplying AC power and one communication cable 5 for communication are provided between the indoor unit and the outdoor unit, and high frequency transformers 14 and 25 in which both ends of primary windings are connected to one connecting cable 4 and the communication cable 5 are provided on the indoor unit 1 and the outdoor unit 2, respectively. Capacitors 15 and 27 are connected in parallel to the primary windings of the high frequency transformers to form parallel resonance circuits to make an alternating signal to be carried to the communication cable 5 to a sine wave-like waveform close to a sine wave.

An electronic device includes a substrate (101), a conductor plane (104) which is provided on an inner layer of the substrate (101), an electronic circuit (102) which is mounted on the substrate (101), a heat sink (103) which is mounted on an upper surface of the electronic circuit (102), includes a portion which does not overlap with the electronic circuit (102) when seen in a plan view, faces the conductor plane (104), and is configured of a conductive material, a conductor via (105) which is connected to the heat sink (103) on a surface of the heat sink (103) contacting the electronic circuit (102), and extends toward the conductor plane (104), and a stub (106) which is connected to the conductor via (105) and extends to face the conductor plane (104).