TWM569111U - Driving integrated circuit for use in alternating current fan motor stepless speed changing - Google Patents

Abstract

A driving integrated circuit includes a sensing unit, a control unit, a pulse width modulation unit, a boosting unit and a driving unit. The sensing unit senses an AC fan motor and generates a sensing output indicating a current speed of the AC fan motor, the control unit includes a lookup table, the lookup table includes a plurality of speed difference values and a plurality of corresponding speeds respectively a control signal of the difference, the control unit generates a speed control signal according to an input signal indicating a target speed, the sensing output and the lookup table, and the pulse width modulation unit generates a modulation signal according to the speed control signal The boosting unit boosts the modulated signal to generate a boosting signal, and the driving unit generates a driving signal related to the target rotational speed according to the boosting signal and outputs the driving signal to the AC fan motor.

Description

Drive integrated circuit for AC fan motor stepless speed change

The present invention relates to a driving integrated circuit, and more particularly to a driving integrated circuit for driving a stepless shift of an AC fan motor.

The prior art mainly uses a conventional variable frequency drive device to receive a power signal from a power source, and controls the speed of an AC motor by a variable frequency drive technology. In detail, the conventional variable frequency drive device includes a control unit, a drive unit and other related units. The control unit is operative to generate a control signal based on an external speed command that indicates a target speed. The driving unit is electrically connected between the power source and the control unit, and generates a frequency and voltage adjusted driving signal according to the control signal and the power signal, and the driving signal is related to the target rotating speed. The conventional variable frequency drive device outputs the drive signal to the AC motor such that the AC motor rotates according to the drive signal and drives a fan to rotate at the target rotational speed to cause the fan to generate a desired air volume.

However, in the conventional variable frequency drive device, the control unit and the drive unit are designed in two separate integrated circuits, resulting in a circuit of a conventional variable frequency drive device. The area is large and the required manufacturing cost is high. Therefore, there is still room for improvement in conventional variable frequency drive devices.

Accordingly, it is an object of the present invention to provide a drive integrated circuit that overcomes the disadvantages of the prior art.

Thus, the novel drive integrated circuit is adapted to receive a power signal from a power source and accordingly generate a drive signal to drive an AC fan motor to steplessly shift. The driving integrated circuit comprises a sensing unit, a control unit, a pulse width modulation unit, a boosting unit, and a driving unit.

The sensing unit senses the AC fan motor and generates a sensing output indicative of a current speed of the AC fan motor and a rotor position of the AC fan motor.

The control unit receives an input signal indicating a target rotational speed and electrically connects the sensing unit to receive the sensing output, the control unit includes a storage module storing a lookup table, the lookup table having a plurality of rotational speed differences And a plurality of control signals respectively corresponding to the difference in the rotational speed, the control unit generates a rotational speed control signal related to the target rotational speed according to the input signal, the sensing output and the lookup table, and the rotational speed control signal is the same One of the control signals.

The pulse width modulation unit is electrically connected to the control unit to receive the rotation speed control signal, and generates a modulation signal whose voltage magnitude has been adjusted according to the rotation speed control signal, and the pulse width of the modulation signal is controlled by the rotation speed control signal. Change and change.

The boosting unit is electrically connected to the pulse width modulation unit to receive the modulated signal, and boosts the modulated signal to generate a boost signal.

The driving unit is electrically connected between the boosting unit and the AC fan motor, and receives the boosting signal from the boosting unit, and generates a driving signal related to the target rotating speed according to the boosting signal, and The drive signal is output to the AC fan motor, which is a high pressure resistant unit.

The function of the present invention is that the sensing unit, the control unit, the pulse width modulation unit, the boosting unit, and the driving unit are integrated in a single driving integrated circuit, so that the driving product of the embodiment is The bulk circuit has a small circuit area and requires a low manufacturing cost.

11‧‧‧Power supply

12‧‧‧AC fan motor

121‧‧‧Rotor

2‧‧‧Sensor unit

20‧‧‧Drive integrated circuit

3‧‧‧Control unit

31‧‧‧ Storage Module

311‧‧‧ lookup table

4‧‧‧ Pulse width modulation unit

5‧‧‧Boost unit

6‧‧‧Drive unit

61‧‧‧Signal Switcher

62, 63‧‧‧ first and second capacitors

64‧‧‧ diode

65, 66‧‧‧ first and second resistors

67, 68‧‧‧ first and second transistors

Bs‧‧‧ boost signal

Cs‧‧‧Speed control signal

Ds‧‧‧ drive signal

Is‧‧‧ input signal

Ms‧‧ ̄ modulation signal

P1~P8‧‧‧first to eighth pins

Ss‧‧‧Sensing output

VCC‧‧‧ power signal

VDD‧‧‧ bias voltage

Other features and effects of the present invention will be apparent from the following description of the drawings, wherein: FIG. 1 is a block diagram illustrating one embodiment of the novel driver integrated circuit; and FIG. 2 is a circuit block A diagram illustrating a driving unit of this embodiment.

Referring to Fig. 1, the novel driving integrated circuit 20 is adapted to be electrically connected between a power source 11 and an AC fan motor 12 including a rotor 121, receiving a power signal VCC from the power source 11 and generating a driving signal Ds accordingly. The AC fan motor 12 is driven to rotate without a step. The driving integrated circuit 20 includes a sensing unit 2, a control unit 3, a pulse width modulation unit 4, a boosting unit 5, and a driving unit 6.

The sensing unit 2 continuously (or periodically) senses a signal generated by the SN polarity change of the AC fan motor 12 and the rotor 121 to generate a sensing output Ss indicating the AC fan motor. 12 current speed and a rotor position of the rotor 121 of the AC fan motor 12. In this embodiment, the sensing unit 2 is a Hall sensing unit.

The control unit 3 receives an input signal Is indicating a target rotational speed and electrically connects the sensing unit 2 to receive the sensed output Ss. The control unit 3 includes a storage module 31 for storing a lookup table 311. The lookup table 311 includes a plurality of rotational speed differences and a plurality of control signals respectively corresponding to the equal rotational speed differences. The control unit 3 generates a rotation speed control signal Cs related to the target rotation speed based on the input signal Is, the sensing output Ss and the lookup table 311, and the rotation speed control signal Cs is one of the control signals. In detail, the control unit 3 first subtracts the current rotational speed of the AC fan motor 12 indicated by the sensing output Ss from the target rotational speed indicated by the input signal Is to obtain a current rotational speed difference, and then according to the Current speed difference from the check A lookup table comparison is performed in the lookup table 311, and a control signal corresponding to the difference in the rotational speed corresponding to the current rotational speed difference is used as the rotational speed control signal Cs.

It should be noted that, in this embodiment, the control unit 3 is a programmable control unit. The input signal Is is generated by a user from a user input interface (not shown) in response to an input operation of a pair of target rotational speeds, that is, the user can arbitrarily adjust the target rotational speed, according to the The drive integrated circuit 20, which generates the drive signal Ds by the input signal Is, can drive the AC fan motor 12 to achieve a stepless shift. The speed difference values and the control signals contained in the lookup table 311 are pre-established by the user via a program setting, and the user can continuously update the lookup table 311. The rotational speed control signal Cs is used to increase the rotational speed of the AC fan motor 12, to reduce the rotational speed, or to maintain the rotational speed. For example, when the current speed difference is negative (or positive), it represents that the current speed of the AC fan motor 12 is greater than (or is less than) the target speed, and the control unit 3 proceeds from the lookup table 311 according to the current speed difference. The rotational speed control signal Cs obtained in the middle is used to lower the rotational speed (or increase the rotational speed) of the AC fan motor 12. When the current rotational speed difference is zero, it represents that the current rotational speed of the AC fan motor 12 is equal to the target rotational speed, and the rotational speed control signal Cs generated by the control unit 3 is used to maintain the AC fan motor 12 at the rotational speed.

The pulse width modulation unit 4 is electrically connected to the control unit 3 to receive the rotation speed control signal Cs, and generates a voltage level adjusted according to the rotation speed control signal Cs. The modulation signal Ms (the voltage of the modulation signal Ms is 12V), and the pulse width of the modulation signal Ms changes with the change of the rotation speed control signal Cs. For example, when the current rotational speed difference is a negative number and the rotational speed control signal Cs is used to decrease the rotational speed of the AC fan motor 12, the pulse width of the modulated signal Ms is narrowed as the rotational speed control signal Cs changes. . On the other hand, when the current rotational speed difference is a positive number and the rotational speed control signal Cs is used to increase the rotational speed of the AC fan motor 12, the pulse width of the modulated signal Ms is widened as the rotational speed control signal Cs changes.

The step-up unit 5 is electrically connected to the pulse width modulation unit 4 to receive the modulation signal Ms, and boosts the modulation signal Ms to generate a boost signal Bs (the voltage of the boost signal Bs is 24V~48V), so that the voltage of the boosting signal Bs is sufficient to drive the driving unit 6.

The driving unit 6 is electrically connected between the boosting unit 5 and the AC fan motor 12, and receives the boosting signal Bs from the boosting unit 5, and generates the related rotating speed according to the boosting signal Bs. Driving the signal Ds, and outputting the driving signal Ds to the AC fan motor 12, so that the AC fan motor 12 rotates according to the driving signal Ds and drives a fan (not shown) to rotate at the target rotation speed to make the fan Produce the desired amount of wind. In the present embodiment, the drive unit 6 is a unit of high pressure resistant specifications. The driving signal Ds has a voltage of 110 V or 220 V and a frequency of 50 Hz or 60 Hz. The driving unit 6 can drive a high-power AC fan motor with a required power of 20W~90W to rotate.

Referring further to FIG. 2, the driving unit 6 includes a signal switch 61, first and second capacitors 62, 63, a diode 64, first and second resistors 65, 66, and first and second electrodes. Crystals 67, 68.

The signal switcher 61 has first to eighth pins P1 to P8. The first pin P1 receives the power signal VCC, and the second and third pins P2 and P3 are electrically connected to the boosting unit 5 and In conjunction with receiving the boost signal Bs, the fourth pin P4 is electrically connected to ground.

The first capacitor 62 is electrically connected between the first and fourth pins P1, P4. The second capacitor 63 is electrically connected between the sixth and eighth pins P6 and P8. The diode 64 has an anode electrically connected to the first pin P1 and a cathode electrically connected to the eighth pin P8. The first resistor 65 has a first end electrically connected to the seventh pin P7 and a second end. The second resistor 66 has a first end electrically connected to the fifth pin P5 and a second end. The first transistor 67 has a first end receiving a bias voltage VDD, a second end electrically connected to the sixth pin P6, and a control end electrically connected to the second end of the first resistor 65. . The second transistor 68 has a first end, a second end electrically connected to the ground, and a control end electrically connected to the second end of the second resistor 66. The output of the first end of the second transistor 68 and the second end of the first transistor 67 serves as the driving signal Ds.

It should be noted that, in this embodiment, the first capacitor 62 is a polarity capacitor, and the first and second resistors 65 and 66 are each a current limiting resistor. Device. Each of the first and second transistors 67, 68 is an N-type MOS field effect transistor, wherein the drain, source and gate of the N-type MOS field-effect transistor are respectively the first The first end, the second end, and the control end of each of the second transistors 67, 68. In addition, the signal switcher 61 functions to switch the boosted signal Bs received by its own internal switch to shift the clock of the boost signal Bs to be outputted from the seventh pin P7. A signal is used to drive the first transistor 67, and another signal is output from the fifth pin P5 to drive the second transistor 68. In addition, the signal switcher 61 continuously detects that the first transistor 67 is normally output or locked via the sixth pin P6. If the first transistor 67 is locked, the signal switcher 61 will The reset signal is output to the eighth pin P8 via the sixth pin P6 and the second capacitor 63 for resetting. The detailed circuit structure of the signal switcher 61 has a variety of different implementations and is well known to those of ordinary skill in the art, and thus will not be described herein.

In summary, since the sensing unit 2, the control unit 3, the pulse width modulation unit 4, the boosting unit 5, and the driving unit 6 are integrated in a single driving integrated circuit 20, As a result, the driving integrated circuit 20 has a smaller circuit area than the conventional variable frequency driving device, and the required manufacturing cost is low. In addition, the driving integrated circuit 20 is obtained because the sensing unit 2 continuously senses the sensing output Ss obtained by the AC fan motor 12 to know the current rotational speed of the AC fan motor 12 and the rotor position of the rotor 121. According to the driving signal Ds generated by the sensing output Ss, the transistor (not shown) in the AC fan motor 12 can be switched to zero point, and the The AC fan motor 12 does not generate a reverse electromotive force to the driving unit 6, so that the driving unit 6 can be prevented from being damaged by the reverse electromotive force, so that the service life of the driving integrated circuit 20 of the present embodiment is prolonged. Moreover, the sensing unit 2 continuously senses the AC fan motor 12, so that the driving integrated circuit 20 can automatically adjust the driving signal Ds according to the sensing output Ss continuously output by the sensing unit 2. Therefore, the driving integrated circuit 20 can achieve the real rotation speed detection and speed control of the AC fan motor 12, and avoid the situation that the rotation speed of the AC fan motor 12 does not reach the target rotation speed due to the difference in quality or aging of the AC fan motor 12 itself.

However, the above is only the embodiment of the present invention, and when it is not possible to limit the scope of the present invention, all the simple equivalent changes and modifications according to the scope of the patent application and the contents of the patent specification are still This new patent covers the scope.

Claims (6)

A driving integrated circuit adapted to receive a power signal from a power source and generate a driving signal to drive an AC fan motor stepless shifting, the driving integrated circuit comprising: a sensing unit sensing the AC fan a motor to generate a sensing output, the sensing output indicating a current speed of the AC fan motor and a rotor position of the AC fan motor; a control unit receiving an input signal indicating a target speed and electrically connecting the sensing unit To receive the sensing output, the control unit includes a storage module storing a lookup table, the lookup table having a plurality of rotational speed differences and a plurality of control signals respectively corresponding to the difference in rotational speeds, the control unit according to the input The signal, the sensing output, and the lookup table generate a rotational speed control signal associated with the target rotational speed, the rotational speed control signal being one of the control signals; a pulse width modulation unit electrically coupled to the control unit Receiving the speed control signal and generating a voltage level adjusted according to the speed control signal Changing the signal, and the pulse width of the modulated signal changes according to the change of the rotational speed control signal; a boosting unit electrically connecting the pulse width modulation unit to receive the modulated signal, and raising the modulated signal Pressing to generate a boost signal; and a driving unit electrically connected between the boosting unit and the AC fan motor, and receiving the boosting signal from the boosting unit, and generating the correlation according to the boosting signal Driving signal at the target speed, and driving the drive The signal is output to the AC fan motor, which is a high pressure resistant unit. The driving integrated circuit of claim 1, wherein the sensing unit is a Hall sensing unit, and the sensing unit continuously senses the AC fan motor. The drive integrated circuit of claim 1, wherein the control unit is a programmable control unit. The driving integrated circuit of claim 1, wherein the control unit subtracts the current rotational speed of the AC fan motor indicated by the sensing output from the target rotational speed indicated by the input signal to obtain a current rotational speed difference. And performing a table lookup comparison according to the current speed difference value from the lookup table, and using one control signal corresponding to the difference in the speed difference corresponding to the current speed difference value as the rotation speed control signal. The driving integrated circuit of claim 1, wherein the driving unit comprises: a signal switch having first to eighth pins, the first pin receiving the power signal, the second and third The pin is electrically connected to the boosting unit and cooperates to receive the boosting signal, the fourth pin is electrically connected to the ground; a first capacitor is electrically connected between the first and fourth pins; and a diode , having an anode electrically connected to the first pin, and a cathode electrically connected to the eighth pin; a second capacitor electrically connected between the sixth and eighth pins; a first resistor, Having a first end electrically connected to the seventh pin, and a second end; a second resistor having a first end electrically connected to the fifth pin and a second end; a first transistor having a first end receiving a bias voltage and an electrical connection a second end of the pin, and a control end electrically connected to the second end of the first resistor; and a second transistor having a first end, a second end electrically connected to the ground, and an electric Connecting the control end of the second end of the second resistor, the output of the first end of the second transistor and the second end of the first transistor serves as the driving signal. The driving integrated circuit of claim 5, wherein the first capacitor is a polar capacitor, and the first and second resistors are each a current limiting resistor.