Abstract: A method for controlling a fan in a fan start-up stage including a first time period and a second time period comprises the following steps of: during the first time period, continuously providing a first driving signal to drive the fan; and during the second time period, continuously providing a second driving signal to drive the fan; wherein, the signal value of the first driving signal gradually decreases until being equal to the signal value of the second driving signal. Wherein the signal value of the first driving signal non-linearly decreases, the signal value of the second driving signal is an unchanged value. Wherein, the first time period and the second time period are adjusted for a different fan but the sum of the first time period and the second time period is always the same. A fan is also disclosed.

Abstract: A motor is provided and driven by two phase. The first and second control signals have a phase difference of 90 degrees and are configured to control the first and second driving units, respectively, and the first and second control signals drive the first and second coil sets, respectively. Each of the first and second poles of the permanent magnet occupies a mechanical angle of 360/2n degrees of the permanent magnet, respectively, and n is 1 or 3. The four sets of the coils of the stator are equally located on the stator, each set of the coil occupies a mechanical angle of 360/2m degrees of the stator, any two sets of the coils adjacent to each other are separated by a mechanical angle of 90?(360/2m) degrees, and m is 3 or 2, wherein m corresponds to 2 when n is 1, m corresponds to 3 when n is 3.

Abstract: A method for controlling a fan in a fan start-up stage including a first time period and a second time period comprises the following steps of: during the first time period, continuously providing a first driving signal to drive the fan; and during the second time period, continuously providing a second driving signal to drive the fan; wherein, the signal value of the first driving signal gradually decreases until being equal to the signal value of the second driving signal. Wherein the signal value of the first driving signal non-linearly decreases, the signal value of the second driving signal is an unchanged value. Wherein, the first time period and the second time period are adjusted for a different fan but the sum of the first time period and the second time period is always the same. A fan is also disclosed.

Abstract: A method for controlling a fan in a fan start-up stage including a first time period and a second time period comprises the following steps of: during the first time period, continuously providing a first driving signal to drive the fan; and during the second time period, continuously providing a second driving signal to drive the fan; wherein, during the first time period the signal value (driving energy) of the first driving signal gradually decreases until being equal to the signal value of the second driving signal, and the signal value of the first driving signal is initially greater than the signal value of the second driving signal. A fan is also disclosed.

Abstract: A method for controlling a fan in a fan start-up stage including a first time period and a second time period comprises the following steps of: during the first time period, continuously providing a first driving signal to drive the fan; and during the second time period, continuously providing a second driving signal to drive the fan; wherein, during the first time period the signal value (driving energy) of the first driving signal gradually decreases until being equal to the signal value of the second driving signal, and the signal value of the first driving signal is initially greater than the signal value of the second driving signal. A fan is also disclosed.

Abstract: A heat dissipation device is applied to an electronic device and comprises a heat conduction plate, at least an induction coil and a first heat dissipation plate. The heat conduction plate receives the heat provided by a heat source and includes a first contact element disposed on a first surface of the heat conduction plate. The induction coil is disposed at the heat conduction plate. The first heat dissipation plate is disposed at the first contact element of the heat conduction plate. The first heat dissipation plate and the heat conduction plate form a gap. The first heat dissipation plate includes at least a first magnetic element disposed opposite the induction coil.

Abstract: A motor drive circuit including a back electromotive force detecting module and a processing module is disclosed herein. The back electromotive force detecting module is electrically connected to a single phase DC motor and is configured to detect a back electromotive force of the single phase DC motor and to output a detecting signal correspondingly. The processing module is electrically connected to the back electromotive force detecting module and the single phase DC motor. The processing module is configured to determine the rotation direction of the single phase DC motor according to the detecting signal and a hall signal outputted by a hall element located in the single phase DC motor, and is configured to control the single phase DC motor.

Abstract: A heat dissipating apparatus includes a frame, an elastic body, a magnetic member and a coil. The frame has an opening. The elastic body is disposed on the frame, and the frame and the elastic body define a space. The magnetic member is located corresponding to the space and disposed at one side of the elastic body. The coil is located corresponding to the periphery of the space and disposed on the frame. An electronic device with the heat dissipating apparatus is also disclosed.

Abstract: A single phase brushless DC motor comprises a Hall effect sensor, a coil assembly and a motor control circuit which generating a driving signal to guide a coil current flowing through the coil assembly. The Hall effect sensor senses the magnetic pole of the rotor to accordingly generate a Hall effect signal. The motor control circuit outputs a current polarity reverse signal according to the voltage at one end of the coil assembly. The time when the current polarity reverse signal is generated corresponds to the polarity reverse time of the coil current. The motor control circuit adjusts the phase of the driving signal according to the polarity reverse time of the Hall effect signal and the time when the current polarity reverse signal is generated to synchronize the phase of the back emf of the single phase brushless DC motor with the phase of the coil current.

Abstract: A single phase brushless DC motor comprises a Hall effect sensor, a coil assembly and a motor control circuit which generating a driving signal to guide a coil current flowing through the coil assembly. The Hall effect sensor senses the magnetic pole of the rotor to accordingly generate a Hall effect signal. The motor control circuit outputs a current polarity reverse signal according to the voltage at one end of the coil assembly. The time when the current polarity reverse signal is generated corresponds to the polarity reverse time of the coil current. The motor control circuit adjusts the phase of the driving signal according to the polarity reverse time of the Hall effect signal and the time when the current polarity reverse signal is generated to synchronize the phase of the back emf of the single phase brushless DC motor with the phase of the coil current.

Abstract: A driving circuit drives a motor containing a first coil and a second coil. The driving circuit includes a switching unit, an operation unit and a control unit. The switching unit receives a switching signal from the control unit for driving the motor. The control unit detects the rotation speed of the motor. When the rotation speed of the motor is greater than a predetermined rotation speed, the control unit outputs a first operation signal to the operation unit to couple the first terminals of the first and second coils and couple the second terminals of the first and second coils. When the rotation speed of the motor is less than or equal to the predetermined rotational speed, the control unit outputs a second operation signal to the operation unit to couple the second terminal of the first coil to the first terminal of the second coil.

Abstract: A method for controlling a fan in a fan start-up stage including a first time period and a second time period comprises the following steps of: during the first time period, continuously providing a first driving signal to drive the fan; and during the second time period, continuously providing a second driving signal to drive the fan; wherein, during the first time period the signal value (driving energy) of the first driving signal gradually decreases until being equal to the signal value of the second driving signal, and the signal value of the first driving signal is initially greater than the signal value of the second driving signal. A fan is also disclosed.

Abstract: A motor drive circuit including a back electromotive force detecting module and a processing module is disclosed herein. The back electromotive force detecting module is electrically connected to a single phase DC motor and is configured to detect a back electromotive force of the single phase DC motor and to output a detecting signal correspondingly. The processing module is electrically connected to the back electromotive force detecting module and the single phase DC motor. The processing module is configured to determine the rotation direction of the single phase DC motor according to the detecting signal and a hall signal outputted by a hall element located in the single phase DC motor, and is configured to control the single phase DC motor.

Abstract: A heat dissipation device is applied to an electronic device and comprises a heat conduction plate, at least an induction coil and a first heat dissipation plate. The heat conduction plate receives the heat provided by a heat source and includes a first contact element disposed on a first surface of the heat conduction plate. The induction coil is disposed at the heat conduction plate. The first heat dissipation plate is disposed at the first contact element of the heat conduction plate. The first heat dissipation plate and the heat conduction plate form a gap. The first heat dissipation plate includes at least a first magnetic element disposed opposite the induction coil.

Abstract: A driving circuit drives a motor containing a first coil and a second coil. The driving circuit includes a switching unit, an operation unit and a control unit. The switching unit receives a switching signal from the control unit for driving the motor. The control unit detects the rotation speed of the motor. When the rotation speed of the motor is greater than a predetermined rotation speed, the control unit outputs a first operation signal to the operation unit to couple the first terminals of the first and second coils and couple the second terminals of the first and second coils. When the rotation speed of the motor is less than or equal to the predetermined rotational speed, the control unit outputs a second operation signal to the operation unit to couple the second terminal of the first coil to the first terminal of the second coil.

Abstract: A heat dissipating apparatus includes a frame, an elastic body, a magnetic member and a coil. The frame has an opening. The elastic body is disposed on the frame, and the frame and the elastic body define a space. The magnetic member is located corresponding to the space and disposed at one side of the elastic body. The coil is located corresponding to the periphery of the space and disposed on the frame. An electronic device with the heat dissipating apparatus is also disclosed.

Abstract: A fan rotary speed controlling device includes a first signal generating circuit, a second signal generating circuit, a pulse width modulation (PWM) circuit and a switching circuit. The first signal generating circuit receives a real frequency signal and a target frequency signal, and generates a first signal according to the real frequency signal and the target frequency signal. The second signal generating circuit generates a second signal according to the first signal. The PWM circuit generates a PWM signal according to the second signal. The switching circuit is electrically connected with the PWM circuit and outputs a control signal to control the rotary speed of the motor. Hence, the fan rotary speed controlling device boosts the accuracy and the stability of the fan rotary speed.

Abstract: A fan rotary speed controlling device includes a base voltage generating circuit, a first voltage generating circuit, a second voltage generating circuit and a compensation controlling circuit. The base voltage generating circuit receives a pulse width modulation signal and outputs a base voltage signal. The first voltage generating circuit receives the pulse width modulation signal and generates a first voltage signal according to the pulse width modulation signal. The second voltage generating circuit receives a fan rotary speed signal and generates a second voltage signal according to the fan rotary speed signal. The compensation controlling circuit outputs a voltage deviation compensation signal according to the first voltage signal and the second voltage signal. Hence, the fan rotary speed controlling device provides a stable rotary speed.

Abstract: A motor control apparatus and a motor control method determine whether the motor is in a back-pressure area so as to provide different rotation-speed control signals. When the fan is in the low duty cycle, a first circuit loop is switched on, so that the fan has more accurate rotation speed. When the fan is in the high duty cycle, a second circuit loop is switched on, so that the rotation speed of fan does not be limited to a constant rotation-speed as the fan enters the back-pressure area. Thus, the fan has larger airflow quantity and higher airflow pressure.

Abstract: A motor control apparatus includes a sensing module, a phase modulating module, a duty cycle modulating module and a driving module. The sensing module detects a motor to generate a sensing signal. The phase modulating module receives the sensing signal and generates a phase modulation signal in accordance with the sensing signal. The duty cycle modulating module receives the phase modulation signal and generates a duty cycle modulation signal in accordance with the phase modulation signal. The driving module receives the duty cycle modulation signal and generates a motor control signal for controlling the motor in accordance with the duty cycle modulation signal.