Abstract: An electrically-operated architectural covering that can be powered by a low current or voltage source includes a motor, an accumulator connected to the motor, a power source, and an electrical circuit connecting the power source to the accumulator. The electrical circuit includes a step-up converter, which preferably includes an input terminal connected to the power source; an output terminal with a supply voltage connected to the accumulator; an inductive element; a first switch having a gate electrode for opening and closing of the switch when a control voltage of a first level is applied to the gate; and an oscillator.

Abstract: An abnormality detector for motor drive system easily detects, using a CPU, abnormality such as short circuit or disconnection in magnetic field coils of a motor, wiring, an open/close element, etc., which are controlled by a microprocessor (CPU). The open/close elements conducting an open/close operation sequentially in response to pulse outputs P1, P2 generated by the CPU, drive the magnetic field coils. Surge voltages generated upon interrupting the mentioned open/close elements are OR connected through a diode, and input to a temporary storage circuit. Then the CPU reads out, stores and resets the surge voltages using pulse edges of the pulse output P1 or P2. When any generation of the surge voltage is not stored in the temporary storage circuit, the CPU operates an abnormality alarm display.

Abstract: A wiper device for a window, in particular in a motor vehicle, including a wiper blade, a mechanical system that drives the wiper blade, and a control device that compensates for the clearances of the mechanical system as a function of load changes and/or as a function of service life and a method for operating such a wiper device.

Abstract: An electrically-operated architectural covering that can be powered by a low current or voltage source includes a motor, an accumulator connected to the motor, a power source, and an electrical circuit connecting the power source to the accumulator. The electrical circuit includes a step-up converter, which preferably includes an input terminal connected to the power source; an output terminal with a supply voltage connected to the accumulator; an inductive element; a first switch having a gate electrode for opening and closing of the switch when a control voltage of a first level is applied to the gate; and an oscillator.

Abstract: Door sensor(s) 6, 7 may be attached to door body or bodies 3 of automatic swing doors. Door sensor(s) 6, 7 may be equipped with door position detecting means 67, 77 comprising geomagnetic sensor(s); sensor(s) 6, 7 being itself or themselves capable of detecting position(s) occupied by door body or bodies 3 during opening and/or closing thereof. During opening and/or closing of door body or bodies 3, determination may be made as to whether detected object(s) are object(s) intended for detection; and in the event that object(s) are object(s) intended for detection, opening and/or closing of door body or bodies 3 may be stopped, slowed, and/or reversed in correspondence to detected position(s) occupied by door body or bodies 3 during opening and/or closing thereof.

Abstract: A rain sensor includes an amplifier circuit that amplifies an output voltage from a photodiode and then provides this voltage signal to a CPU. The amplifier circuit conducts an offset amplification. The output voltage from the amplifier circuit is controlled to be at a predetermined level, for example, 3.0V, and the CPU detects rainfall based on the drop in the output voltage from the predetermined level, 3.0V. Then it becomes possible to improve sensor sensitivity, maintain a small sensor size, and a low manufacturing cost.

Abstract: A position adjusting system for adjusting the position of a seat n a vehicle and preventing movement of the seat resulting from external forces acting on the seat. The system includes a seat track fixable to the vehicle, a motor actuator, and a gear train engaged with the motor actuator. The seat track is adapted to cooperate with the seat track to convert movement of the motor actuator into movement of the seat track and the seat. A non-reversing clutch mechanism is coupled with the gear train and adapted to transfer torque from the motor actuator through the gear train to move the seat upon actuation of the motor actuator but locking upon torque being applied through the seat track, thereby preventing the external forces acting on the seat from moving the seat relative to the vehicle.

Abstract: A power window apparatus for a vehicle is comprised of an operation switch which includes a raising contact for outputting a window raising command when set at on-state and a lowering contact for outputting a window lowering command when set at on-state, and a controller which is arranged to execute a manual operation during a time period from a start moment at which the operation switch starts outputting one of the window raising and lowering commands to a first moment at which a first predetermined time period elapses from the start moment, to execute an automatic operation during a time period from the first moment to a second moment at which a second predetermined time period elapses from the start moment, and to execute the manual operation from the second moment.

Abstract: A garage door drive assembly for moving a linkage arm connected to a garage door, the assembly being adapted for shipping in a partially assembled condition in at least a box for on-site installation, the assembly has a longitudinally-extending rail with laterally extending flanges. The assembly also has a carriage shaped to fit about the flanges. A drive mechanism is movably mounted to the rail. An anchor is coupled to the drive mechanism. The assembly also has a coupler with a selectively releasable connection to the anchor, a connector pivotably connectable to the linkage arm, and a detachable connection enabling the coupler to be fixedly secured to and carried by the carriage. The rail and the carriage may be shipped to the installation site in a box having a smaller cross-sectional profile than would be required to accommodate the carriage and coupling in their connected state.

Abstract: A process to start a brushless direct current motor with a multiphase stator winding is disclosed, in which, during rotor standstill, a plurality of current impulses is intruded on the stator winding, the current rise time until a current threshold is reached is measured in the stator winding with every current impulse and the rotor position is derived from the measured current rise times. A more precise determination of rotor position is achieved with lower control-related effort for a regulated sensorless start-up in that a plurality of test current impulses is successively intruded on the stator winding in such a way that the test current impulses generate stator flow vectors offset by the same angular increments over 360° electrically in the stator. The current rise time for each stator flow vector is measured in the total current of the stator winding and the phase position of the stator flow vector with the smallest current rise time is determined as the rotor position.

Abstract: A powered window system for a vehicle is disclosed. The powered window system includes a window moveable between an open and a closed position. A motor is coupled to the window. The motor causes selective movement of the window. At least one of a switch and a communications bus is coupled to the motor. A processor is coupled to at least one of the switch and the communications bus and is configured to selectively send at least one of close and open signals to at least one of the switch and the communications bus. A sensor is coupled to the processor and senses conditions on which automated window closure is based. The sensor sends condition signals to the processor. The processor interprets the condition signals and selectively sends a closed signal to at least one of the switch and the communications bus when the conditional signal exceeds a prescribed threshold.

Abstract: When abnormal current due to jamming is detected through motor current (ID), the motor current (ID) performs an operation in which an ON/OFF operation and a continuous ON operation are repeated, so that increment of the motor current (ID) is restrained. At this time, determination of jamming is performed based on the ON/OFF operation and the continuous ON operation. When the jamming is determined, the motor current (ID) is stopped, and the motor is reversed.

Abstract: A floor mopping assembly finding use in a cleaning robot. The cleaning robot may be remotely controlled or autonomous. In one embodiment, a feed roller lets out a roll of webbing or toweling, a take-up roller reels in the toweling, and a motor system causes transfer of the toweling between the feed roller and the take-up roller. A housing holds the motor system and the rollers, which are mounted in the housing such that the motor causes transfer of the webbing between the rollers. One of the rollers is configured to rest on the floor or surface so as to cause the toweling to clean the surface. In an alternative embodiment, the assembly also includes a pad to press the toweling against the surface, where the pad is mounted in the housing such that the motor causes transfer of the toweling between the rollers and between the pad and the surface.

Abstract: A circuit is arranged control the acceleration of a fan by limiting the rate of change in fan speed control signals. The control system includes an acceleration controller that low pass filters a target fan speed control signal. The low pass filtering signal minimizes abrupt changes in the fan speed. A sudden change in the speed of the fan often results in an audible noise that is undesirably distracting. Filtering the fan speed control signal advantageously slows the rate of the fan speed changes without having to change device drivers for controlling the fan.

Abstract: In a motor driving device that drives a motor by energizing a coil of a first phase and a coil of a second phase provided in the motor in one direction alternately, which phase to energize is switched according to a back electromotive force appearing in the coil of each phase of the motor as a rotor of the motor rotates. This circuit configuration eliminates the need for an external sensor to detect the position of the rotor, and thus helps promote cost reduction and miniaturization. Here, where no external sensor is used to detect the position of the rotor, the motor is started by first bringing the rotor to rest in a particular position and then energizing the coil of a particular phase. This permits the motor to be started always in the same rotation direction, and thus helps prevent reverse rotation of the motor.

Abstract: The present method and system allows minimization of a rollback effect when an electric vehicle, such as a wheelchair, brakes on a slope. The system comprises secondary brake, a controller, and a monitor that allows to apply both a control voltage and the secondary brakes according to an appropriate sequence to provide stops and starts with a minimized rollback effect. An updated armature resistance value is advantageously used to take into account evolutive conditions of the vehicle.

Abstract: A circuit configuration for operating an electric motor (46) is described, the circuit configuration containing a timer (22). As a function of a first differential signal (15) between a setpoint signal (11) and an actual value signal (14), a regulator supplies a first switch signal (20) for feeding current to the electric motor (46). Simultaneously, the timer (22) is started which limits the current feed signal (45) to a specified maximum time (Tmax). A detection system (37) detects a change in the setpoint signal (11) and thereupon outputs a second switch signal (38) that also starts the timer (22) and is able to trigger the current feed to the electric motor (46). The circuit configuration both protects the electric motor (46) from a thermal overload and also makes it possible to feed current to the electric motor (46) if a setpoint changes.

Abstract: A control system for preventing a sudden change in the passengers' feeling for the acceleration. After determining whether the assistance using the motor is permitted with respect to each of different control modes, an amount of assistance for each mode is calculated. If the output assistance is permitted in any mode, the maximum amount of assistance is selected, and a previous value of the maximum amount of assistance is compared with the current value of the maximum amount of assistance. A shift value is obtained by subtracting a predetermined assistance value from the previous value when the current value is less than the previous value, and the amount of assistance is set to the shift value until the shift value becomes equal to or less than the current value, so as to gradually shift the amount of assistance from the previous value to the current value.

Abstract: In a case in which an operation is alternately carried out by apparatus-1 and the apparatus-2 in cooperation with a robot, an operator carries out operation within an operation range of each of the apparatuses during the interruption of power supply to the apparatus-1 and the apparatus-2. Even if the operator approaches or enters the apparatus-1 or the apparatus-2, an emergency stop unit is not informed of a notice of such approach or entry as far as the interruption of power to the apparatus is confirmed. In a state in which the interruption of power is not confirmed, on the other hand, the emergency stop unit is informed of the notice of operator's approach or entry, and the robot system is emergency stopped.

Abstract: A movable barrier operator having improved safety and energy efficiency features automatically detects line voltage frequency and uses that information to set a worklight shut-off time. The operator automatically detects the type of door (single panel or segmented) and uses that information to set a maximum speed of door travel. The operator moves the door with a linearly variable speed from start of travel to stop for smooth and quiet performance. The operator provides for full door closure by driving the door into the floor when the DOWN limit is reached and no auto-reverse condition has been detected. The operator provides for user selection of a minimum stop speed for easy starting and stopping of sticky or binding doors.

Abstract: A closure system including a closure moveable for substantially closing an aperture in use, and an actuator for at least closing the closure, the actuator being mounted by mounting means, the mounting means including one or more measurement cells for measuring, in use, parameters of the closure systems, in use the system being subjected to movement and being arranged such that it is possible to at least partially distinguish trap forces applied to the closure from acceleration forces applied to the closure as a result of the movement of the closure system by consideration of the measured parameters.

Abstract: The invention concerns a method for controlling a motor vehicle wiper motor comprising steps which consist in: determining at least a range related to an operating parameter of the motor and capable of having several non null values; comparing said range with a predetermined threshold (high LS, low; HS, high INT, low LS, low INT); and controlling the motor on the basis of the result of the comparison. The range is determined when the rotor of the motor occupies a determining position corresponding to a predetermined point on a trajectory of a blade driven by the motor.

Abstract: A control circuit controls a coffee grinder having a grinder motor. The control circuit includes a timer portion and a first switch. The first switch functions as a two-condition switch to place the control circuit in one of (1) an off condition when the first switch is open and the timer portion and the grinder motor are de-energized and (2) a run condition when the first switch is closed, the timer portion is energized, and the grinder motor is energized once in the run condition, the control circuit remaining in the run condition until the timer portion times out or until the first switch is re-opened thereby returning the control circuit to the off condition.

Abstract: A windscreen wiper device and a method for wiping windscreens, including at least one motor whose direction of rotation can be altered, at least one wiper which is coupled to the motor and which moves back and forth between two reversing positions, a control device which switches the motor by means of switching signals and operating signals which are conveyed to the control device. The control device determines the switching signals from the operating signals to determine the reversing positions of the wiper. The degree of wetness of the windscreen surface is conveyed to the control mechanism and used as an operating signal.

Abstract: A power window switch circuit, even if soaked, prevents windows from opening or closing unintentionally. A DOWN switch (128) and an UP switch (129) each include a first fixed contact (DN1, UP1) connected with a power supply, a second fixed contact (DN2, UP2) grounded, and movable contacts (131, 132, 133, 134) for selectively connects either the first or second fixed contact with the first terminal of corresponding relay coils (21, 23). A transistor (TR4) responsive to a soak signal is connected between the ground and the second fixed contacts (DN2, UP2) of the UP and DOWN switches. The second terminals of the first and second relay coils are grounded through their respective transistors. When a soak is detected, a soak detector (15) supplies a soak signal to the transistors.

Abstract: The invention relates to an assembly for adjusting mobile elements of furniture, comprising a motor, a control circuit which is provided with push-button switches, a current supply circuit, a mains connection, a mains supply circuit, a mains isolating relay and an auxiliary current source. The aim of the invention is to construct said assembly in a more cost-effective manner whilst at the same time retaining a safety isolation from the mains. To achieve this, the first push-button switch forms a direct electric circuit with the motor and the control input of the isolating relay is connected in parallel to the motor, or is connected to the latter via a Graetz bridge.

Abstract: In a method for operating an actuating device in a motor vehicle including the steps of measuring an actuating force exerted by the actuating drive, comparing the actuating force to a limit force, and reversing the actuating drive if the limit force is exceeded, provision is made that, while the motor vehicle is being driven, the measured values of the actuating force are filtered, prior to the comparison operation, in accordance with a first method, to suppress rapid changes in the actuating force on the basis of the path covered by the actuating drive, and, while the motor vehicle is at rest, with the engine turned off, in accordance with a second method where rapid changes are suppressed to a lesser extent than in the first method, or not filtered at all. A device for carrying out the method is specified.

Abstract: A vehicle with a tailgate (5) or the like, the vehicle being defined in that the tailgate (5) has a sensor for sensing objects at least during the opening operation.

Abstract: A vehicle seat includes a seat movable along a path a motor for driving the seat on the path, a sensor generating a signal indicating movement of the seat on the path, and a controller operating the motor to move said seat along the path. The sensor is preferably a Hall-effect device or a potentiometer. The controller is in communication with the sensor to receive the signal and form a feed-back control loop. The controller accelerates the seat at a controlled rate of acceleration to a controlled constant speed and decelerates the seat from the constant speed at a controlled rate of deceleration. The controller controls the rate of acceleration of the seat at a stored predetermined rate of acceleration by adjusting operation of the motor to maintain the predetermined rate of acceleration.

Abstract: Methods and apparatus for controlling an automatic barrier movement system, particularly for beginning movement of a barrier which has been stopped between an open and closed position of the barrier. The receipt of a barrier movement command will generally start movement of the barrier toward the open position, however, when predetermined conditions are met the barrier may be started in a direction determined by a preprogrammed algorithm. The predetermined conditions may include that the barrier has been stopped for less than 5 minutes and/or that the barrier was stopped in response to an obstruction during travel toward the open position. The preprogrammed algorithm may be to move the barrier toward the closed position or move the barrier in a direction determined from other sensed conditions.

Abstract: A door operator for moving a door includes a motor for moving the door between opened and closed positions, an operator for controlling the operation of the motor, and a switch, such as a wired wall station or a remote transmitter, for enabling the operator to control operation of the motor. Pushing and releasing the switch results in the operator allowing the motor to apply a normal range of torque values, and wherein pushing and holding the switch results in the operator allowing the motor to apply a broader-than-normal range of torque values. An external safety device coupled to the operator may be used with the operator. If the external safety device is enabled and the door is closing, the motor allows application of a higher-than-normal range of torque values. The door operator may also take corrective action if excessive door speed is detected. But, this corrective action can be overridden if the switch is held closed for a predetermined time.

Abstract: A position adjusting system for adjusting the position of a seat n a vehicle and preventing movement of the seat resulting from external forces acting on the seat. The system includes a seat track fixable to the vehicle, a motor actuator, and a gear train engaged with the motor actuator. The seat track is adapted to cooperate with the seat track to convert movement of the motor actuator into movement of the seat track and the seat. A non-reversing clutch mechanism is coupled with the gear train and adapted to transfer torque from the motor actuator through the gear train to move the seat upon actuation of the motor actuator but locking upon torque being applied through the seat track, thereby preventing the external forces acting on the seat from moving the seat relative to the vehicle.

Abstract: A starter control system is comprised of a starter motor, a control circuit for controlling the starter motor to rotate at a preliminary rotation speed that is high enough to engage a pinion with an engine for a predetermined time and low enough to suppress a harsh noise caused when the pinion engages the engine and, thereafter, at a normal rotation speed that is high enough to start the engine, and a control circuit for changing the preliminary rotation speed according to an engine temperature. The starter control system is effective to reduce noises that are caused when the engine is started by an economy-run system.

Abstract: A controller for a shutter moved between an opened position and a closed position. A plurality of location ranges is defined between the opened position and the closed position. The controller detects the current moving speed of the shutter in each range, compares the moving speed with a predetermined reference speed, and generates a stop signal based on the comparison result to stop the movement of the drive mechanism.

Abstract: A power-window safety device which includes an annular magnet 21 mounted on a rotary shaft (9a) of a drive motor (9) for opening and closing a window glass of an automotive vehicle, and a magnetic flux sensor (20), disposed facing the annular magnet (21), for sensing a change of a magnetic flux developed from the annular magnet (21), which change in flux is caused by rotation of the rotary shaft (9a). The magnetic flux sensor includes Hall ICs (22A and 22B). An operational element (24A, 24B) performs a process of linearly approximating a sinusoidally varying voltage output from a Hall element (23A, 23B) which is provided in association with the operational element, and produces an output voltage (VA, VB) thus processed. Every angular position of the rotary output shaft, or every opening/closing position of the window glass, is detected over the range of one complete rotation on the basis of the output voltages (VA and VB) that are generated through the rotation of the rotary shaft (9a).

Abstract: In an apparatus for controlling extension and retraction of a shielding member, a bi-directional motor has a drive shaft coupled to the shielding member. A processing unit is operable in a normal operating mode, where the processing unit controls the motor for moving a free end of the shielding member between predetermined extended and retracted positions based on extended and retracted position information stored in a memory. When supply of electric power to the apparatus is interrupted, the processing unit determines current position information from motor rotation signals provided by a sensor unit such that the processing unit is able to automatically control the motor for moving the free end of the shielding member when supply of the electric power to the apparatus is resumed.

Abstract: The invention relates to a process for adjusting a motor vehicle part between at least two positions, the motor vehicle part being driven by an electric motor, pulse signals being generated according to the rotary motion of the electric motor and being supplied to a control unit for controlling the electric motor, in the first computation (50) with a first parameter set the first value for the instantaneous force acting on the motor vehicle part is determined from the acquired pulse signals at certain first instants. Parallel to the first computation, in at least the second computation (52) with a second parameter set which differs from the first parameter set the second value for the instantaneous force acting on the motor vehicle part is determined from the acquired pulse signals at certain second instants, the two values being considered for the instantaneous action of the force in order to decide whether the electric motor is turned off or reversed or not.

Abstract: A method and system of controlling a movable body portion of a vehicle where the body portion is moved by a motor responding to a control input. Power is applied to the motor upon actuation of the control input and a timer is maintained concurrent with the application of power. Power is removed from the motor as a function of expiration of the timer or relinquishment of the control input. The timer provides a maximum amount of time that power may be applied to the motor, thereby preventing damage to the movable body portion in the event it becomes jammed while being moved by the motor.

Abstract: A safety-guard detective circuit of a fan motor includes a resistor being adapted to limit a large current input into the motor driver circuit, and a discharge member being adapted to perform grounding to discharge the large current limited by the resistor. The resistor and the release member are commonly connected to the third lead of the motor driver circuit.

Abstract: An improved garage door opener is disclosed. The garage door opener has a motor drive unit for opening and closing a garage door. The motor drive unit has a microcontroller. Connected to the motor drive unit is a wall console that resides inside the garage. The wall console also has a microcontroller. The microcontroller of the motor drive unit is connected to the microcontroller of the wall console by means of a digital data bus.

Abstract: A wiper control device in which an abnormal condition of a FET is detected by distinguishing an action of an overheat-cutting protective function normally difficult to be detected with measuring the drain voltage of the FET and by which the control of the pertinent FET is restrained upon the detection of abnormality so as to prevent a short circuit in the wiper control device from occurring. When an FETB (Qb) is set on, whether or not a drain voltage Vd is lower than Vpe ({fraction (l/2)}VG) is judged (step S5), and if lower, it is judged that the drain and ground is short-circuited, that is, an overheat-cutting protective function is acted, and “1” is added to the number of times of short circuit detection Perror (step S7). It is judged whether or not the added value of the number of times of short circuit detection Perror reaches a reference value (step S11).

Abstract: An electrically moving apparatus for moving a movable body includes a security mechanism for detecting an abnormal increase of a load applied to the movable body during the movable body being moved by an operation of an electric motor. The electrically moving apparatus does not require an increase of a threshold value for judging the increase of the load applied to the movable body. The security mechanism is not operated when an increase of a load for lifting down an operative member being movable in response to the movement of the movable body.

Abstract: An adjustment device for adjusting an article of furniture, includes a drive unit having at least one direct current positioning motor connected to a mains power source; a control unit with at least one switching device for actuating the positioning motor(s); and a mains disconnect relay connected to a mains power plug assembly or a supply line connecting the voltage source to the mains. An additional switching unit which is separate from the switching device(s) for actuating the positioning motor(s) is provided for actuating the mains disconnect relay.

Abstract: An AC motor is utilized to drive a closure on a vehicle. The use of the AC motor provides valuable benefits with regard to cost and size. Further, a three-phase AC motor may be utilized, and the pulses in its power supply monitored to determine an obstruction in the path of the closure. Frequency control may also be utilized to provide optimum control of the drive of the component at both start-up and stop.

Abstract: An electric motor for operating a device for wiping a window of a motor vehicle has an electric motor part, and a control device for controlling/regulating a power of the electric motor part, the control device being formed so that it is programmable with a parameter a power limiting by limiting a torque to a nominal torque.

Abstract: The wiper control device comprises a wiper motor 52 for moving a wiper, a switch 53 for outputting a signal which inverts at each single sweep of the wiper, a wiper switch circuit 51 of a combination switch which instructs movement of the wiper, a first solid state switching element FET-b which drives the wiper motor, a controller 55 which turns the first solid state switching element on and off intermittently on the basis of the signal from the switch in a case in which intermittent wiper movement is instructed by the combination switch, a second solid state switching element FET-a2 which is connected in series to the first solid state switching element and is turned on by power source voltage, and a third solid state switching element FET-a1 which is connected in series to the second solid state switching element and is for braking the wiper motor.

Abstract: Disclosed is a circuit and method for preventing erroneous opening and closing caused particularly, by use of a DC motor in an automatically/manually foldable portable radio terminal having a main body and a sub-body rotatable with respect to the main body. In the circuit, a motor provides rotating force to automatically raise or lower the sub-body, a motor driver drives the motor according to a motor driving direction control signal, an inverse electromotive force eliminator eliminates inverse electromotive force by opening or shorting both terminals of the motor according to an automatic mode or a manual mode, and a motor power controller controls supplying a driving power voltage to the motor. In the method of operating a folder, it is determined whether an automatic folder operation key has been pressed. Upon receipt of the automatic folder operation key input, a rectifier is turned on to open both terminals of a motor. At the end of the opening of the motor terminals, the motor is driven.

Abstract: A motor control circuit includes a first winding switch, a first switch driver circuit, and a current sense circuit. The first winding switch has a control input and is operable to activate a first motor winding. The first switch driver circuit is coupled to the control input. The current sense circuit is operably coupled to a second winding. The current sense circuit includes a sense resistor, the sense resistor comprising an etched trace in a printed circuit board. The etched trace has a geometry defining a resistance of the sense resistor.

Abstract: The invention relates to a process for adjusting a motor vehicle part between at least two positions and a drive device for executing this process. The motor vehicle part is driven by an electric motor, and a pulse signal is generated according to the rotary motion of the electric motor which is supplied to a control unit for controlling the electric motor, in which at certain instants the value for the current force acting on the motor vehicle part is determined from the pulse signal. This value of the force is used as the criteria in the decision whether the electric motor is to be turned off or reversed [or not]. Before connection of the electric motor to the motor vehicle part measurements are taken on the electric motor for determining the individual motor characteristics, the measured values determined in this way are used in the determination of the value of the action of force.

Abstract: A sensorless motor starting system of a simplified structure is capable of starting a sensorless spindle motor under optimal target starting conditions with low power consumption in accordance with the motor type and the kind of an optical disc to be driven, by executing manual fine adjustment of start parameters in response to any abnormal rotation caused at the start time. In this system, a rotation frequency signal is outputted from an edge detector on the basis of position signals in a start acceleration mode, and then is compared with a reference frequency signal by a comparator. And if the result of the decision therefrom signifies abnormal rotation, a switch is turned to its another terminal to select a manual setting mode. An operator performs manual fine adjustments of a phase switching time, a phase switching number and a drive voltage in order while monitoring phase switching control signals and position signals to thereby normalize the start state of the sensorless spindle motor.