Electricity: power supply or regulation systems – External or operator controlled – Using a three or more terminal semiconductive device as the...
Reexamination Certificate
1999-08-03
2001-05-15
Nguyen, Matthew (Department: 2838)
Electricity: power supply or regulation systems
External or operator controlled
Using a three or more terminal semiconductive device as the...
Reexamination Certificate
active
06232758
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention generally relates to a load drive control apparatus. This invention particularly relates to an apparatus including a circuit for driving and controlling a load on an electric power source in response to a given condition.
2. Description of the Related Art
Air conditioners for automotive vehicles include blower motors and cooling fan motors which are loads on vehicular batteries. It is desirable to reduce electric power consumption during suspension of such motors.
A known load drive control apparatus associated with an air conditioner includes a relay switch connected between a vehicular battery and a motor. When the air conditioner is turned off, the relay switch is changed to its open position so that the feed of electric power from the battery to the motor is cut off. The power cutoff enables power economy. In the known load drive control apparatus, the relay switch is required to have a great rating current. Accordingly, the relay switch tends to be large in size and expensive.
SUMMARY OF THE INVENTION
It is an object of this invention to provide an inexpensive load drive control apparatus.
A first aspect of this invention provides a load drive control apparatus comprising a drive control circuit for driving and controlling a load in response to a given drive condition; a power supply circuit for feeding drive electric power to the drive control circuit; and mode change means for controlling feed of the drive electric power to the drive control circuit by the power supply circuit in response to a control signal for drive and control of the load to implement a change between a normal mode of operation and a stand-by mode of operation in which consumed electric power is reduced.
A second aspect of this invention provides a load drive control apparatus comprising a drive control circuit for driving and controlling a load in response to a given drive condition; a power supply circuit for feeding drive electric power to the drive control circuit; and mode change means for controlling feed of the drive electric power to the drive control circuit by the power supply circuit in response to a control signal for drive and control of the load to implement a change between a normal mode of operation and a stand-by mode of operation in which the feed of the drive electric power to the drive control circuit by the power supply circuit is suspended.
A third aspect of this invention is based on the first aspect thereof, and provides a load drive control apparatus wherein the mode change means comprises a capacitor, a charging/discharging change circuit for selectively charging and discharging the capacitor in response to the control signal, and means for implementing a change between the normal mode and the stand-by mode in response to a voltage at an end of the capacitor.
A fourth aspect of this invention is based on the third aspect thereof, and provides a load drive control apparatus wherein the control signal includes a pulse signal having a duty cycle which depends on the drive condition, and the mode change means comprises a charging circuit for charging the capacitor by a charging current, and a discharging circuit for discharging the capacitor at a discharging current, and wherein a ratio between the charging current and the discharging current is substantially equal to a duty cycle of the pulse signal which corresponds to a threshold value for a change between the normal mode and the stand-by mode.
A fifth aspect of this invention is based on the fourth aspect thereof, and provides a load drive control apparatus wherein the duty cycle corresponding to the threshold value is smaller than a duty cycle of the pulse signal which corresponds to a condition of starting drive of the load.
A sixth aspect of this invention is based on the first aspect thereof, and provides a load drive control apparatus wherein the control signal includes a pulse signal having a frequency which depends on the drive condition, and the mode change means comprises means for detecting the frequency of the pulse signal, and means for implementing a change between the normal mode and the stand-by mode in response to the detected frequency of the pulse signal.
A seventh aspect of this invention is based on the first aspect thereof, and provides a load drive control apparatus further comprising a main power source, and wherein the power supply circuit derives the drive electric power from main electric power fed from the main power source, and wherein the mode change means comprises means for detecting a voltage of the main power source, and means for changing a timing of a change between the normal mode and the stand-by mode in response to the detected voltage of the main power supply.
An eighth aspect of this invention is based on the first aspect thereof, and provides a load drive control apparatus further comprising means for detecting a drive condition of the load, and means for generating the control signal in response to the detected drive condition, and wherein the mode change means comprises means for detecting whether or not drive of the load is suspended on the basis of the control signal, and means for implementing a change from the normal mode to the stand-by mode when it is detected that the drive of the load is suspended.
A ninth aspect of this invention is based on the eighth aspect thereof, and provides a load drive control apparatus wherein the mode change means comprises means for detecting whether or not the drive of the load is abnormal, and means for implementing a change from the normal mode to the stand-by mode when it is detected that the drive of the load is abnormal.
A tenth aspect of this invention is based on the first aspect thereof, and provides a load drive control apparatus further comprising means for detecting a condition of control by the drive control circuit, and means for generating the control signal in response to the detected control condition, and wherein the mode change means comprises means for detecting whether or not the control by the drive control circuit is abnormal, and means for implementing a change from the normal mode to the stand-by mode when it is detected that the control by the drive control circuit is abnormal.
An eleventh aspect of this invention is based on the first aspect thereof, and provides a load drive control apparatus wherein the power supply circuit comprises switching elements for controlling feed of the drive electric power to the drive control circuit, a voltage boosting circuit for boosting a voltage of the drive electric power, and a voltage-drop compensation circuit for compensating for a voltage drop caused by the switching elements on the basis of the boosted voltage generated by the voltage boosting circuit.
A twelfth aspect of this invention is based on the first aspect thereof, and provides a load drive control apparatus further comprising a voltage boosting circuit for boosting a voltage of the drive electric power fed from the power supply circuit, and a power generation circuit for generating boosted electric power on the basis of the boosted voltage generated by the voltage boosting circuit, and for feeding the boosted electric power to the drive control circuit.
A thirteenth aspect of this invention is based on the twelfth aspect thereof, and provides a load drive control apparatus wherein the power generation circuit comprises means for starting operation of the voltage boosting circuit when the mode change means implements a change from the stand-by mode to the normal mode.
A fourteenth aspect of this invention is based on the first aspect thereof, and provides a load drive control apparatus wherein the drive control circuit comprises switching elements for controlling the load, and means for turning on at least one of the switching elements to brake the load when the normal mode has been replaced by the stand-by mode.
A fifteenth aspect of this invention is based on the first aspect thereof, and provides a load drive control apparatus wherein the control s
Asai Satoru
Goto Kunihiko
Konda Shinichi
Denso Corporation
Nguyen Matthew
Pillsbury & Winthrop LLP
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