Denso Corporation

Satoshi Yoshimura

Masao Yamada

Toshiki Sugiyama

Kazuhiro Takeuchi

Atsushi Kanamori

Koji Nakamura

Junji Sugiura

Takuya Usami

Manabu Nomura

Masatoshi Yokai

Tetsuo Fujii

Akira Ando

Kouji Nakamura

Masatoshi Youkai

Akira Andoh

An electric device includes: a circuit board arranged in cooling medium in a housing and having an electric element and an external coupling electrode, wherein the electric element is sealed in and mounted in a substrate, and the electric element is electrically coupled with the external coupling electrode; an external coupling terminal electrically coupled with the external coupling electrode; and a separation member for separating the external coupling terminal and a connection portion between the external coupling electrode and the external coupling terminal away from the cooling medium.

Electric device mounted in electric compressor

A load drive device for driving an inductive load by PWM controlling a switching element includes synchronization control unit, a synchronization signal input terminal, and a synchronization signal output terminal. The synchronization control unit outputs the PWM signal to the switching element. The synchronization control unit receives a synchronization signal through the input terminal from an exterior. The synchronization control unit outputs the synchronization signal through the output terminal to an exterior. When the synchronization control unit does not receive the synchronization signal, the synchronization control unit outputs the synchronization signal such that a first switching period of the PWM signal is prevented from overlapping with a second switching period of a PWM signal of an external device. When the synchronization control unit receives the synchronization signal, the synchronization control unit generates the PWM signal based on the synchronization signal.

Load drive device and control system of the same

A rotor position detecting circuit includes a first position detecting circuit having a low-pass filter that shapes up phase voltage induced in a phase coil and a first comparator that compares the output voltage of the low-pass filter with a threshold level to form a first rotor position signal, and a second position detecting circuit having a second comparator that compares the phase voltage with a threshold voltage and a control unit that digitally processes the output voltage of the second comparator to form a second rotor position signal. The control unit corrects the first rotor position signal by the second rotor position signal to provide a final rotor position signal when the rotation speed of the brushless DC motor is in a measurable range.

Rotor position sensing system of brushless motor

A load control device includes a control circuit and a protection circuit. The control circuit controls driving of an electric load. The protection circuit monitors a power supply voltage supplied to the control circuit and stops control of driving the load by the control circuit, when the power supply voltage drops below a threshold value. The protection circuit provides the threshold value with a hysteresis characteristic having a width determined by a product of a wiring resistance of a path for supplying a driving current to the load and a maximum value of the driving current.

Load control device and method

A load drive apparatus includes a noise filter, which includes a coil connected in series between a power source and a load, and a switching transistor connected in parallel across the coil, and a control circuit which is operated based on a drive signal. The control circuit turns on the switching transistor of the noise filter in case of subjecting the load to a full-on drive, thereby to short-circuit the coil and to form a power supply path including the switching transistor without the coil. The control circuit turns off the switching transistor of the noise filter in case of subjecting the load to a PWM drive, thereby to form a power supply path including the coil.

Load drive apparatus

An inverter apparatus includes an inverter circuit, a temperature sensor, and a control circuit. The inverter circuit is driven by a PWM signal and includes switching elements that are divided in first and second groups. The temperature sensor detects a temperature of at least one of the switching elements of the first group. The control circuit controls a duty cycle of the PWM signal such that a first value of heat generated in the first group is equal to or greater than a second value of heat generated in the second group. The control circuit performs an overheat protection for protecting the inverter circuit from overheating when the detected temperature is equal to or greater than a threshold temperature.

Apparatus and method for driving inverter circuit

In a control apparatus for a motor, which rotates a fan, a semiconductor device is connected to the motor in series to drive the motor. An analog driver circuit drives the semiconductor device with an analog voltage. A PWM control circuit drives the semiconductor device with a PWM signal of a frequency of less than several tens. A switching control circuit selects the analog driver circuit and the PWM control circuit when the motor is to be rotated at speeds lower and higher than a predetermined speed, respectively.

Semiconductor device control apparatus and method

In a control apparatus for a motor, an over-current protection circuit detects an abnormality in a motor current forcibly turns off a MOSFET. The over-current protection circuit has a timer function and a time switching function. In the timer operation, the over-current protection circuit stops an abnormality detection signal for an ON time period before producing the signal for an OFF time period when a current flowing through the motor exceeds a predetermined threshold value. The time switching function is for controlling to lengthen the OFF time period to a relatively larger value in comparison with the ON time period.

Motor control apparatus

A temperature sensor () detects the temperature of a MOS transistor (), and a current detecting circuit () detects current flowing in the MOS transistor (). When the voltage corresponding to the detected temperature or the voltage corresponding to the detected current is increased to a threshold value or more, an overheat state detecting signal and further switching signal is set to a high level. As a result, a switch circuit in a driving circuit () is turned on, and the gate resistance value becomes the parallel value of a resistor (), and the PWM frequency in the PWM control circuit is lowered, whereby the switching loss of the MOS transistor () can be reduced under the state that the motor () is rotated.

Motor driving device

A drive apparatus for driving two motors by PWM control of respective switching elements connected to the motors, whereby respective control signals are applied to the switching elements such that each commencement of a transition of one of the switching elements from the non-conducting to the conducting state coincides with the termination of a transition of the other switching element from the conducting to the non-conducting state, thereby reducing generated electrical noise, and for supplying equivalent values of drive voltage to two motors of different power ratings which rotate respective cooling fans, to obtain equalized levels of air flow rate.

Drive apparatus for PWM control of two inductive loads with reduced generation of electrical noise

A cooling fan motor drive apparatus for use in vehicle is equipped with first to fourth semiconductor switches for driving first and second cooling fan motors upon receipt of a power supply voltage through power supply lines. A control unit implements control on openings and closures of the first to fourth switches to establish first and second power supply systems between first and second power supply lines for performing serial and parallel operations of the first and second cooling fan motors. The control unit closes the second and fourth semiconductor switches when the first and second cooling fan motors are driven in series and closes the first, second and third semiconductor switches when the first and second cooling fan motors are drive in parallel. When an overcurrent flows in the cooling fan motors, the control unit conducts the serial operation of the cooling fan motors irrespective of an operation command signal, and at the start-up of the drive apparatus, the control unit conducts the serial operation thereof for a predetermined time period. This drive apparatus can be located in the vicinity of the cooling fan motors and, even if an abnormal condition occurs temporarily, can restore to a normal condition after the recovery.

Drive apparatus for cooling fan motor for use in vehicle

A cooling fan control circuit drives a brushless motor to rotate a cooling fan to cool a condenser and a radiator mounted on a vehicle when a drive signal is activated. In a situation where the brushless motor rotates at a rotational speed equal to or higher than a predetermined value by flowing air in a situation that the drive signal is not activated and a charge state signal indicating that a battery is not in a fully charged state, the control circuit turns off MOSFETs in upper arms of an inverter circuit and simultaneously, synchronously switches MOSFETs in lower arms of the inverter circuit. With this configuration, an electric energy generated by the flowing air is stored from the brushless motor to a battery.

Apparatus for controlling cooling fan for vehicle

When air passing through a condenser and a radiator passes through a cooling fan in a state where a driving circuit controls a voltage applied to a motor to be constant in accordance with a motor application voltage instructed by a control signal Sa, a motor current Im decreases. A comparator compares the motor current Im with a reference current set on the basis of a motor voltage Vm. When the motor current Im decreases to a value equal to or lower than the reference current, a switching circuit is switched to select an output signal of an operational amplifier. The operational amplifier performs a feedback control so that the motor voltage Vm coincides with a minimum application voltage VL.

Apparatus and method for controlling cooling fan for vehicle

An error such as disconnection or short on the current path from said dc power supply to a switching element via the dc motor is detected by judging whether variation in a voltage at a junction point between the dc motor and the switching element tracks variation in the pulse width modulation signal for the switching element. If this is false for a predetermined interval, this apparatus judges there is the error. The error is judged by variation in a voltage at a junction point between the dc motor and the switching element tracks variation in the pulse width modulation signal, so that though the dc motor is driven by a fan for cooling the engine of a motor vehicle because of wind due to traveling of a motor vehicle, the error can be judged accurately.

Motor driving apparatus

A vehicle cooling apparatus having a simple construction that enables the size of a cooling fan electric motor to be reduced without the need to increase the number of batteries provided for driving the motor. The cooling fan provides necessary cooling for an engine radiator and an air-conditioning system condenser by driving the motor at an input power lower than its rated power by a predetermined amount until the temperature of the engine cooling water reaches a predetermined temperature. If the water temperature rises above the predetermined temperature, the electric motor input power is increased to a level greater than its rated input power for a predetermined time period. As a result, cooling capacity can be increased and the water temperature can be lowered with a smaller motor when the water temperature has become abnormally high. Because the electric motor is normally driven at an input power lower than its rated input power, the life of the electric motor is increased.

Growing community of inventors

Kariya, Japan

Satoshi Yoshimura