Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A temperature sensor (33) detects the temperature of a MOS transistor (7), and a current detecting circuit (35) detects current flowing in the MOS transistor (7). 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 (17) is turned on, and the gate resistance value becomes the parallel value of a resistor (25), and the PWM frequency in the PWM control circuit is lowered, whereby the switching loss of the MOS transistor (7) can be reduced under the state that the motor (2) is rotated.

Abstract: 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.

Abstract: 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.

Abstract: A temperature sensor (33) detects the temperature of a MOS transistor (7), and a current detecting circuit (35) detects current flowing in the MOS transistor (7). 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 (17) is turned on, and the gate resistance value becomes the parallel value of a resistor (25), and the PWM frequency in the PWM control circuit is lowered, whereby the switching loss of the MOS transistor (7) can be reduced under the state that the motor (2) is rotated.

Abstract: 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.

Abstract: In a display device including a cathode filament containing a coiled portion and a linear portion thereof and a power feeding member, an end of the coiled portion is fixed to either a substrate made of an insulating material or an insulated support, the power feeding member being installed to contact with the linear portion of the cathode filament.

Abstract: 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.

Abstract: The present invention provides a data recording-reproduction device comprising a manipulation button 10 having a recording button, reproduction button and an INDEX button. A control microcomputer 7 prepares a file name including a file ID number and an index number in response to the manipulation of the recording button, starts to write digital data, and thereafter updates the index number included in the file name in response to the manipulation of the INDEX button to continue to write the digital data with a new file name. Furthermore, the control microcomputer starts to read digital data having a selected file name in response to the manipulation of the reproduction button, and updates the index number included in the file name in response to the subsequent manipulation of the INDEX button followed by reading digital data having a new file name.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A filament core wire capable of being mounted while having tension at a predetermined level applied thereto without an expensive anchor and without applying unnecessary tension thereto. The filament core wire is provided at a part thereof with spring and welded sections. The sections each are covered with a heat-decomposable block element made of acrylic resin or the like. Also, the core wire has a carbonate deposited thereon. The core wire is mounted on a mounting position by removing the block element from the welded section of the wire arranged on the fixing position by heating and then welding the welded section to a fixing spot of the fixing position. Then, block element is removed from the spring section by heating. This permits the filament core wire to be stretchedly arranged at the mounting position while keeping tension applied to the core wire to provide it with elasticity.

Abstract: In the test of semiconductor non-volatile memories having floating gates, a plurality of memory cells that are connected to an identical word line are programmed simultaneously. A voltage to complete programming these memory cells is the final voltage. After erasing all of the memory cells, a disturbance stress pulse train having voltages changing in increments are applied up to or before the final voltage. Almost simultaneously, the semiconductor non-volatile memory is tested by measuring the lowest threshold voltage among the memory cells on each word line.

Abstract: A filament core wire capable of being mounted while having tension at a predetermined level applied thereto without an expensive anchor and without applying unnecessary tension thereto. The filament core wire is provided at a part thereof with spring and welded sections. The sections each are covered with a heat-decomposable block element made of acrylic resin or the like. Also, the core wire has a carbonate deposited thereon. The core wire is mounted on a mounting position by removing the block element from the welded section of the wire arranged on the fixing position by heating and then welding the welded section to a fixing spot of the fixing position. Then, block element is removed from the spring section by heating. This permits the filament core wire to be stretchedly arranged at the mounting position while keeping tension applied to the core wire to provide it with elasticity.

Abstract: In a display device including a cathode filament containing a coiled portion and a linear portion thereof and a power feeding member, an end of the coiled portion is fixed to either a substrate made of an insulating material or an insulated support, the power feeding member being installed to contact with the linear portion of the cathode filament.