Denso Corporation

Nippon Soken, Inc.

Keiji Shigeoka

Koji Kawasaki

Yuji Hayashi

Tsuyoshi Yamashita

Kimikazu Nakamura

Shinya Goto

Hiroyuki Mori

Hirofumi Kinjou

Tomohisa Kishigami

Yoshifumi Kaku

Norio Sanma

Sei Iguchi

Hideki Kashima

Hirofumi Kinjo

Kenji Tomita

Shogo Akasaki

In a power converter, a reference signal generator generates a reference signal with a predetermined period. A current detector detects a current flowing in the converter. When a value of the detected current is larger than a value of a predetermined current command, a reset signal generator generates a reset signal. A driving unit drives a switch. The switch is turned on, and subsequently is turned off: (i) in synchronization with the reference signal when the reset signal is not outputted before the reference signal is outputted; and (ii) in synchronization with the reset signal when the reset signal is outputted before the reference signal is outputted. However, the switch is turned off in synchronization with the reset signal during a predetermined time including a first predetermined time before an output timing of the reference signal and a second predetermined time after the output timing of the reference signal.

Power converter for driving a switch based on current command and current flowing therein

A signal transmission circuit includes a transceiver, an impedance adjustment circuit, a first control circuit and a second control circuit. The impedance adjustment circuit realizes a low impedance state and a normal state of the transmission line. The first control circuit controls the impedance adjustment circuit to realize the low impedance state for a fixed period that is shorter than a width of one bit, when a change of a signal level on the transmission line is detected. The second control circuit controls the impedance adjustment circuit according to a transmission data transmitted from the transceiver, when detecting that a communication frame wins an arbitration by comparing the transmission data and the received data, to realize the low impedance state in an entire period where the signal level on the transmission line is recessive until transmission of the communication frame ends.

Signal transmission circuit

Each of nodes in a communication system includes a pull-up circuit connected between a power source and a transmission line and a switching portion connecting and disconnecting the transmission line and a ground line. One of the nodes is a master node, and the others of the nodes are slave nodes. The driver circuits are driven so that the master node constantly outputs the transmission code of logic 1 and the slave node outputting the transmission code of logic 0 extends the width of the low level of the transmission code of logic 1 on the transmission line. The master node further includes a current limiting section limiting an electric current that flows to the transmission line via the pull-up circuit based on at least a signal level of the transmission line.

Communication system

A current mode controlled power converter controllable in a digitally processing current mode even during an on time. In the power converter, each control period based on a reference signal includes a slope calculation period in which a slope compensation signal for the control period is calculated by a slope compensation unit. During each slope calculation period, the slope compensation unit negates the slope compensation signal calculated previous to the control period including the slope calculation period, and a reset signal generation unit compares a current detection signal detected by a current detection unit with a current instruction set to an error signal generated by an error signal generation unit to generate a reset signal.

Current mode controlled power converter

A DC-DC converter generates PWM signals PWMH, PWML on the basis of a reference signal CLKto drive switching elements connected in series. When generating a reset signal RST, the converter generates PWM signals PWMH, PWML on the basis of the reset signal RST. When generating no reset signal, the converter generates the PWM signals PWMH, PWML on the basis of a reference signal CLKin order to drive other switching elements connected in series. The converter generates the reset signal RST at an optional timing to the reference signal CLK. The reference signal CLKis brought forward from the reference signal CLKby &#x394;T. The PWM signals PWMH, PWML are different in timing from the PWM signals PWMH, PWML. This makes it possible to avoid the switching elements diagonally arranged from being simultaneously turned on and off, and suppress a switching loss, and to increase an efficiency of the converter.

Electric power conversion circuit

An information presentation device includes: a directional information obtaining element for obtaining directional information based on a signal from an enhancement device for safety or comfort of a passenger of a vehicle; an information presentation controller for generating a driving signal based on the directional information; and a stimulation element including multiple vibrators for generating a traveling wave of vibration in an in-vehicle element. A directionality of the traveling wave corresponds to the directional information. The stimulation element transmits the traveling wave to the passenger so that the passenger perceives the directionality of the traveling wave.

Information presentation device

In a DC to DC converter, first and second primary windings are magnetically coupled to a first secondary winding. Third and fourth primary windings are magnetically coupled to a second secondary winding. The first and second primary windings are magnetically coupled to the first secondary winding. The third and fourth primary windings are magnetically coupled to the second secondary winding. The first and third primary windings are coupled in series to form a first coil member. The second and fourth primary windings are coupled in series to form a second coil member. One end of the first coil member is coupled to the first positive power line. A first switching element is coupled between the first negative power line and the other end of the first coil member. A first capacitor is coupled between the first negative terminal and one end of the second coil member.

DC-DC converter

A switching deviceand a related operating method are disclosed for generate a train of drive pulses under a basic pattern for a repetition cycle time T. The train of drive pulses has leading edges shifted from basic time periods Tby shift amounts &#x3a6;to &#x3a6;, respectively, which are different from each other, whereby switching frequencies, occurring based on the leading edges of the drive pulses, are spread. A spread frequency, which is a inverse number of the cycle time T of the basic pattern, is set to be higher than an audible frequency.

Switching device and related operating method

A switching device comprises a switching element, a setting member, and a control member. The switching element turns on/off in response to a drive signal, so as to control a controlled variable of a controlled system to a desired amount. The setting member sets the drive signal on the basis of both a desired duty to control the controlled variable, wherein the drive signal is set by repeating a basic pattern consisting of a plurality of intervals which are decided to remove overlaps, in a frequency spectrum, between or among switching frequencies produced based on an interval between start timings of the on operations and an interval between start timings of the off operations. The control member variably controls the switching element based on the drive signal.

Device for controlling controlled variable by on/off switching operations with less noise manner

DC-DC converter with capacitor precharging and duty ratio limiting

In a DC to DC converter, a transformer circuit includes a primary winding and a secondary winding member composed of series-connected first to fourth secondary windings having one and the other ends. The one and the other ends of the series-connected first to fourth secondary windings are connected to a first output terminal. The first and second secondary windings are wound around a first magnetic path in opposite directions, and the third and fourth secondary windings are wound around a second magnetic path in opposite directions. A first rectifying element is connected between the second output terminal and a connection point between the first and second secondary windings. A second rectifying element is connected between the second output terminal and a connection point between the third and fourth secondary windings.

Input to output isolated DC-DC converter

A switching device and a method of operating a switching power element are disclosed for generating a train of drive pulses (Dto D) in a basic pattern for a repetition cycle time (T to TF) having leading time intervals (Thto Th, Th' to Th&#x2032;), associated with leading edges (ato a) of the drive pulses, and trailing time intervals (Tlto Tl, Tl&#x2032; to Tl&#x2032;), associated with trailing edges (bto b) of the drive pulses, which are different from each other, whereby switching frequencies and associated harmonics, resulting from the leading edges and the trailing edges of the drive pulses, are diffused. A diffusion frequency, representing an inverse number of the repetition cycle time for the basic pattern is set to be higher than an audible frequency.

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Okazaki, Japan

Keiji Shigeoka