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Patent Issued for Soft-Start and Soft-Lock Start on Motor Driving Apparatus

August 20, 2014



By a News Reporter-Staff News Editor at Electronics Newsweekly -- According to news reporting originating from Alexandria, Virginia, by VerticalNews journalists, a patent by the inventors Lee, Teng-Hui (New Taipei, TW); Yu, Kuo-Yung (New Taipei, TW); Lo, Chen-Pin (New Taipei, TW), filed on December 28, 2011, was published online on August 5, 2014.

The assignee for this patent, patent number 8796975, is Amtek Semiconductor Co., Ltd. (New Taipei, TW).

Reporters obtained the following quote from the background information supplied by the inventors: "The present invention is related to a motor driving apparatus, and more particularly related to a motor driving apparatus with soft-start and soft-lock start function, and an external Pulse Width Modulation (PWM) driving signal is transmitted through a soft-start unit to count the motor rotation signals so as to determine the output of the motor driving apparatus and achieve power-up soft-start function and soft-lock start function.

"In recent years, personal computer (PC), portable computer/notebook (NB) or workstation are well development and the calculation speed of the micro chips (such as central unit processor (CPU) or digital signal processor (DSP)) are increased so fast. However, when the calculation speed of the micro chips is increased and the clock frequency is increased, there is lots of heat generated in the micro chips. The high temperature will result the following issues: the calculation malfunction of the microchip, and the influence of the circuits around the micro chips. Therefore, the thermal function of the micro chips is extremely significant technique.

"Generally, the thermal method of the processing micro chips implements the conventional fans to solve the heat radiation. For example, the motor control driving device is used to turn on the fans to bring cooler air to the surface of the micro chips for heat radiation. However, the conventional method to drive the motor by the motor driving apparatus is required to generate the maximum torque to drive the motor so as to overcome the maximum torque limit. This kind of driving method won't cause any problems when the motor with low power. However, if the motor with high power or small internal resistances is used and the motor power is turned on by the maximum torque, a very large current is generated at the turn-on moment, as shown in FIG. 1a. After the power is turned on, the turn on voltage and the pulse width modulation signal are 100%, obviously, at this moment, the turn-on current is the largest and the noise is the largest. If the motor driving apparatus includes a current protect device, the motor driving apparatus won't be impacted by large current. If the motor driving apparatus doesn't include the current protect device, the motor driving apparatus will be destroyed at the moment when the power is turned on.

"In addition, when the motor is in a lock condition because the irresistible external force of the motor or the inaccuracy of the motor, the motor driving apparatus will restart to drive the motor and confirm the irresistible external force is disappeared after a period of time. When the irresistible external force is disappeared, the motor will restart. At the same situation, in order to make sure the motor to restart, the maximum torque is used to drive the motor as the circumstance when the power is turned on. If the motor with high power or small internal resistances is used and the motor power is turned on by the maximum torque, a very large current is generated at the turn-on moment, as shown in FIG. 1b, and the motor driving apparatus would be destroyed when the motor is restarted.

"In order to overcome the problem of the motor driving apparatus described above, there is a motor driving apparatus with a soft-start and soft lock-start function included in the present invention. An internal PWM control signal is used to count the motor rotation signal in the soft-start unit to determine the output of the motor driving apparatus so as to achieve soft-start and soft lock-start purposes."

In addition to obtaining background information on this patent, VerticalNews editors also obtained the inventors' summary information for this patent: "The main object of the present invention is to provide a motor driving apparatus with soft-start function according to prior art. The output control signal of the motor driving apparatus is determined in accordance with the counting number of the motor rotation signal.

"Another object of the present invention is to provide a motor driving apparatus with a soft-lock start function. The output control signal of the motor driving apparatus is determined in accordance with the counting number of the motor rotation signal.

"Another object of the present invention is to provide a motor driving apparatus with a soft-start and soft-lock start function. The output control signal of the motor driving apparatus is determined in accordance with the counting number of the motor rotation signal. As the peak value of the current of the soft-start or soft-lock start is decreased, the life cycle and reliability of the motor driving apparatus is increased.

"Another object of the present invention is to provide a motor driving apparatus with a soft-start and soft-lock start function. The output control signal of the motor driving apparatus is determined in accordance with the counting number of the motor rotation signal. As the peak value of the current of the soft-start or soft-lock start is decreased, the noise is decreased when the motor driving apparatus is turned on.

"Therefore, according to the objects described above, a motor driving apparatus including a control unit, a soft-start unit and an output unit, and is characteristic by: when an external control signal inputs to the soft-start unit, the soft-start unit generates an internal control signal and when Vcc turns on, a power-up initial signal will be generate; after the power-up initial signal is generated, the control unit transmitting a motor rotation signal to the soft-start unit and selects the internal PWM driving signal to the output unit; when the soft-start unit counts a plurality of the motor rotation signal, the soft-start unit selects the external PWM driving signal to output to the output unit.

"A motor driving apparatus including a control unit, a soft-start unit and an output unit, wherein the control unit includes a motor rotation signal (FG) and a rotation detecting signal (RD) and is characteristic by: when an external control signal inputs to the soft-start unit, the soft-start unit generates an internal PWM driving signal and when Vcc turns on, a power-up initial signal will be generate; after the power-up initial signal is generated, the control unit transmitting a motor rotation signal to the soft-start unit and selects the internal PWM driving signal to the output unit; when the soft-start unit counts a plurality of the motor rotation signal, the soft-start unit selects the external PWM driving signal to the output unit.

"A motor driving apparatus including a control unit, a soft-start unit and a output unit, and is characteristic by: wherein the soft-start unit includes an internal PWM pulse signal generator, a power-up initial generator, a FG counter, a RS latch circuit and a select circuit. The internal PWM pulse signal generator is configured to provide an internal PWM driving signal. The power-up initial generator is configured to provide a power-up initial signal. An input end of the FG counter is connected to the motor rotation signal and the power-up initial signal, and configured to count a plurality of the motor rotation signals (FG) so as to output a control signal. The input end of the RS latch circuit is connected to the power-up initial signal and the control signal outputted by the FG counter so as to output a select signal. A first input end of the select circuit is connected to the external PWM driving signal, a second input end is connected to the internal PWM driving signal, a third input end is connected to the select signal and a output end transmits a soft-start control signal to the control unit and the control unit outputs a PWM driving signal to the output unit.

"A motor driving apparatus including a control unit, a soft-start unit and an output unit, and the control includes provides a rotation detecting signal and is characteristic by: wherein the soft-start unit includes an internal PWM pulse signal generator, a power-up initial generator, a FG counter, a RS latch circuit, and a select circuit. The internal PWM pulse signal generator is configured to provide an internal PWM driving signal. The power-up initial generator is configured to provide a power-up initial signal. An input end of the FG counter is connected to the motor rotation signal and the power-up initial signal, and configured to count a plurality of the motor rotation signal (FG) so as to output a control signal. An input end of the RS latch circuit is connected to the power-up initial signal and the control signal outputted by the FG counter so as to output a select signal. A first input end of the select circuit is connected to the external PWM driving signal, a second input end is connected to the internal PWM driving signal, a third input end is connected to the select signal and a output end transmits a soft-start control signal to the control unit and the control unit outputs a PWM control signal to the output unit."

For more information, see this patent: Lee, Teng-Hui; Yu, Kuo-Yung; Lo, Chen-Pin. Soft-Start and Soft-Lock Start on Motor Driving Apparatus. U.S. Patent Number 8796975, filed December 28, 2011, and published online on August 5, 2014. Patent URL: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=8796975.PN.&OS=PN/8796975RS=PN/8796975

Keywords for this news article include: Electronics, Amtek Semiconductor Co. Ltd..

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Source: Electronics Newsweekly


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