TWI451673B - Fan speed control method and device thereof - Google Patents

Description

Fan speed control method and device thereof

The present invention relates to a fan speed control method and apparatus thereof, and more particularly to a fan speed control method and apparatus thereof that can generate high starting torque.

Referring to FIG. 1 , it is a conventional fan speed control device 9 . The fan speed control device 9 includes at least a voltage dividing circuit 91 and a driving chip 92 . The voltage dividing circuit 91 has two resistors 911, a high voltage terminal 912, a low voltage terminal 913 and a series midpoint 914. The two resistors 911 are connected in series to the high voltage terminal 912 and the low voltage terminal 913. And the series midpoint 914 is a series connection point of the two resistors 911. Wherein, the high voltage terminal 912 is connected to a DC voltage source (Vs) [eg, a DC voltage of 5V or 12V], the low voltage terminal 913 is grounded, and the series connection point 914 is connected to the driving chip 92 to The divided voltage of the series midpoint 914 is input to the drive wafer 92 as a control voltage (Vc). The driving chip 92 has an operating voltage input terminal 921, a control voltage input terminal 922 and a driving voltage output terminal 923. The operating voltage input terminal 921 is connected to the DC voltage source (Vs) to supply the driving chip 92. Operating power; the control voltage input terminal 922 is coupled to the series midpoint 914 of the voltage dividing circuit 91 to receive the control voltage (Vc), and thereby the driving chip 92 generates a DC driving voltage (V) accordingly; The driving voltage output terminal 923 is connected to a fan motor coil (C) to send the DC driving voltage (V) generated by the driving wafer 92 to the fan motor coil (C).

When the fan speed control device 9 is operated, since the DC voltage source (Vs) can pass through the resistor 911 of the voltage dividing circuit 91 to form the control voltage (Vc) at the series connection point 914, only the pre-design is required. The resistance ratio of the two resistors 911 can determine the voltage value of the control voltage (Vc), and the DC driving voltage (V) is generated by the driving chip 92 corresponding to the voltage value of the control voltage (Vc), and The DC drive voltage (V) drives the fan motor through the fan motor coil (C) to complete the rotation speed control of the fan motor. Referring to FIG. 2 together, a full-speed voltage (Vt) is generated at the driving voltage output terminal 923 compared to the voltage directly input to the control voltage input terminal 922 by the DC voltage source (Vs), and the partial voltage is transmitted through the partial voltage. The circuit 91 can cause the drive voltage output 923 to generate a lower rated voltage (Vr) that is controlled to operate at a rated speed that is more suitable for the user's needs.

However, during the operation of the fan speed control device 9, if the rated voltage (Vr) is too low, the power input to the fan motor at the time of starting is too low [ie, only has a low starting torque], so that the fan motor is not easy to be used. The rotation is initiated by the standstill and it takes a long time to accelerate from full rest to the rated speed. In addition, since the fan speed control device 9 operates the fan motor coil (C) with a linear DC drive voltage (V), the fan motor must also be driven at a higher DC drive voltage (V) at the rated speed. Running. For the above reasons, it is necessary to further improve the above-described conventional fan rotational speed control device 9 in order to have the effects of high starting torque, high starting efficiency, and low driving voltage.

The main object of the present invention is to provide a fan speed control method and a device thereof, which can provide a large torque at the time of starting and automatically control the fan motor to operate at a rated speed after completion of startup, thereby improving starting efficiency. The effect.

Another object of the present invention is to provide a fan speed control method and apparatus therefor. The fan speed control method and the device thereof output a pulse width modulation signal control fan motor, which has the effects of reducing operating energy consumption and improving control robustness.

The fan speed control method according to the present invention includes: generating a start pulse width modulation signal to a fan motor coil by a fan driving unit during a starting period, and generating the fan driving unit after the starting period is completed. A steady-state pulse width modulation signal is sent to the fan motor coil, wherein a duty cycle ratio of the start pulse width modulation signal is greater than a duty cycle ratio of the steady state pulse width modulation signal.

The fan speed control method inputs the fan drive unit with a control voltage that exhibits a single voltage value, and the length of the start period is preset to the fan drive unit.

The fan speed control method inputs a control voltage that sequentially displays a starting voltage value and a steady voltage value into the fan driving unit, and the control voltage having the starting voltage value is input to the fan driving unit during the starting period. The control voltage having the steady state voltage value is input to the fan drive unit after the start of the start period.

A fan speed control device according to the present invention includes a control unit and a fan drive unit. The control unit has a voltage dividing circuit and a capacitor, the voltage dividing circuit has a high voltage end, a low voltage end and a series midpoint, and the series midpoint is connected via a first voltage dividing resistor The high voltage terminal is connected to the low voltage terminal via a second voltage dividing resistor, and the capacitor is connected in parallel with the first voltage dividing resistor. The fan driving unit has a control voltage input end and a driving signal output end. The control voltage input end is connected to the serial connection midpoint, and the driving signal output end is connected to a fan motor coil to generate a start pulse width modulation. The signal and a steady-state pulse width modulation signal are sent to the fan motor coil; wherein a duty cycle ratio of the start pulse width modulation signal is greater than a duty cycle ratio of the steady state pulse width modulation signal.

The high voltage end of the voltage dividing circuit is connected to a DC voltage source, and the low voltage end of the voltage dividing circuit is grounded.

The above and other objects, features and advantages of the present invention will become more <RTIgt; Shown is a first embodiment of the fan speed control device of the present invention. The fan speed control device includes a control unit 1 and a fan drive unit 2, wherein the control unit 1 is configured to connect a DC voltage source (Vs) and generate a control voltage (Vc). The fan drive unit 2 is electrically connected to the fan drive unit 2 The control unit 1 and a fan motor coil (C), and the fan driving unit 2 receives the control voltage (Vc) to generate a start pulse width modulation signal (S1) or a steady-state pulse width modulation signal (S2) is sent to the fan motor coil (C), whereby the fan motor provided with the fan motor coil (C) is controlled by the start pulse width modulation signal (S1) or the steady state pulse width modulation signal (S2).

The control unit 1 has a voltage dividing circuit 11 and a capacitor 12. The The voltage dividing circuit 11 includes a high voltage terminal 111, a low voltage terminal 112, a first voltage dividing resistor 113, a second voltage dividing resistor 114 and a series connection point 115, wherein the high voltage terminal 111 is connected The DC voltage source (Vs); the low voltage terminal 112 is grounded, so that the potential of the low voltage terminal 112 is lower than the potential of the high voltage terminal, but the low voltage terminal 112 is also connected to an external input signal source; The first voltage dividing resistor 113 and the second voltage dividing resistor 114 are sequentially connected in series from the high voltage terminal 111 to the low voltage terminal 112; the series connection point 115 is the first voltage dividing resistor 113 and the second point a series connection point between the voltage resistors 114, that is, the series connection point 115 is connected to the high voltage terminal 111 via the first voltage dividing resistor 113, and is connected to the low voltage terminal 112 via the second voltage dividing resistor 114, and The series midpoint 115 is for outputting the control voltage (Vc). The capacitor 12 is connected in parallel with the first voltage dividing resistor 113 of the voltage dividing circuit 11, that is, the capacitor 12 is connected between the high voltage terminal 111 and the series midpoint 115.

The fan driving unit 2 has an operating voltage input terminal 21, a control voltage input terminal 22 and a driving signal output terminal 23, and the working voltage input terminal 21 is connected to the DC voltage source (Vs) to supply the fan driving unit. The operating voltage of the control voltage input terminal 22 is connected to the series midpoint 115 of the voltage dividing circuit 11 to receive the control voltage (Vc), and the fan driving unit 2 generates the starting pulse width modulation accordingly. a signal (S1) or a steady-state pulse width modulation signal (S2); the driving signal output terminal 23 is connected to the fan motor coil (C) to generate the starting pulse width modulation signal generated by the fan driving unit 2 ( S1) or a steady-state pulse width modulation signal (S2) is sent to the fan motor coil (C).

The fan speed control device of the first embodiment of the present invention operates The operation of the fan speed control method for carrying out the present invention is described in detail below. Referring to FIGS. 3 and 4 together, when the DC power of the DC voltage source (Vs) is transmitted to the control unit 1 and the fan drive unit 2 to activate the above-described fan speed control device, the DC power system is The capacitor 12 of the control unit 1 is charged, so that in a start period (Ts) during which the capacitor 12 is charged, the voltage drop caused by the voltage of the DC voltage source (Vs) falls on the capacitor 12 and the second The voltage dividing resistor 114 is on. Therefore, the control voltage (Vc) generated by the series connection point 115 of the control unit 1 during the startup period is a startup voltage value, and the startup voltage value is equal to the voltage of the DC voltage source (Vs) minus the capacitor. 12 voltage during charging. At this time, the fan driving unit 2 that receives the starting voltage value generates the starting pulse width modulation signal (S1) and sends it to the fan motor coil (C), and as the charging saturation of the capacitor 12 increases, the starting pulse The duty cycle ratio of the wide-tuning signal (S1) is decreasing. Subsequently, when the capacitor 12 is fully charged and is in a saturated state (ie, the start period (Ts) ends), the voltage drop caused by the voltage of the DC voltage source (Vs) falls on the first of the voltage dividing circuit 11 The voltage dividing resistor 113 and the second voltage dividing resistor 114 are provided. Therefore, the control voltage (Vc) generated by the series connection point 115 of the control unit 1 after the start of the start period (Ts) is a steady voltage value, and the steady voltage value is the DC voltage source ( The voltage of Vs) is divided by the voltage across the second voltage dividing resistor 114. At this time, the fan driving unit 2 that receives the steady-state voltage value generates the steady-state pulse width modulation signal (S2) and sends it to the fan motor coil (C), and the partial voltage on the second voltage dividing resistor 114 As a fixed value, the duty cycle ratio of the steady-state pulse width modulation signal (S2) is also constant. Wherein, the duty cycle ratio of the start pulse width modulation signal (S1) is greater than the The duty ratio of the steady-state pulse width modulation signal (S2), so that the fan speed control device of the present invention can control the fan motor to operate with a larger torque during the starting period (Ts), and during the starting period (Ts) After the end, the fan motor is controlled to operate at the rated speed. Thereby, the fan speed control method and apparatus of the present invention can provide a large torque at the time of starting to improve the starting efficiency and torque, and can still control the motor to operate at a more demanding and energy-saving speed after the startup is completed. In addition, the start pulse width modulation signal (S1) and the steady state pulse width modulation signal (S2) generated by the fan driving unit 2 of the present invention have low energy consumption of pulse width modulation (PWM) and The utility model has the advantages of high anti-interference and the like, and therefore the fan speed control method and device of the invention can not only further reduce the operating energy consumption after the end of the starting period (Ts), but also provide higher control robustness.

Referring to Figures 5 and 6, there is shown a second embodiment of the fan speed control device of the present invention. Compared with the foregoing first embodiment, the control unit 1 of the present invention omits the provision of the capacitor 12, and the fan driving unit 2' of the embodiment is a pre-programmed wafer (for example, a microcontroller chip). The (MCU) is configured to preset the length of time of the start-up period (Ts) in the fan drive unit 2', or is formed by a wafer that has been built with the start-up period (Ts) at the time of shipment. The fan driving unit 2' can first amplify and convert the control voltage (Vc) received in the startup period (Ts) into a PWM signal, or output the duty ratio directly in the startup period (Ts). 100% pulse width modulation signal. Therefore, as shown in FIGS. 5 and 6, the control unit 1 is only used by the voltage dividing circuit 11 in the startup period (Ts) or after the startup period (Ts) ends. The series midpoint 115 produces a single voltage value (ie, The steady-state voltage value is a control voltage (Vc), but the fan drive unit 2' can still generate the start pulse width modulation signal (S1) in the start-up period (Ts), and during the start-up period (Ts) The steady state pulse width modulation signal (S2) is generated after the end.

In summary, the fan speed control method of the present invention can send the start pulse width modulation signal (S1) to the fan motor coil (C) during the start period (Ts), and during the start period (Ts) After the end, the steady-state pulse width modulation signal (S2) is sent to the fan motor coil (C), so that the fan motor controlled by the fan speed control device of the present invention can have high starting torque, high starting efficiency and low Drive voltage and other effects.

While the invention has been described in connection with the preferred embodiments described above, it is not intended to limit the scope of the invention. The technical scope of the invention is protected, and therefore the scope of the invention is defined by the scope of the appended claims.

〔this invention〕

1‧‧‧Control unit

11‧‧‧voltage circuit

111‧‧‧High voltage end

112‧‧‧Low voltage end

113‧‧‧First voltage divider resistor

114‧‧‧Second voltage divider resistor

115‧‧‧Sequential midpoint

12‧‧‧ capacitor

2‧‧‧Fan drive unit

2'‧‧‧Fan drive unit

21‧‧‧Working voltage input

22‧‧‧Control voltage input

23‧‧‧Drive signal output

C‧‧‧Fan motor coil

S1‧‧‧Start pulse width modulation signal

S2‧‧‧ Steady-state pulse width modulation signal

Ts‧‧‧ start-up period

Vc‧‧‧ control voltage

Vs‧‧‧ DC voltage source

[study]

9‧‧‧Fan speed control device

91‧‧‧voltage circuit

911‧‧‧Resistors

912‧‧‧High voltage end

913‧‧‧low voltage end

914‧‧‧ tandem midpoint

92‧‧‧Drive chip

921‧‧‧Working voltage input

922‧‧‧Control voltage input

923‧‧‧Drive voltage output

V‧‧‧DC drive voltage

Vr‧‧‧ rated voltage

Vt‧‧‧ full speed voltage

Figure 1: Circuit diagram of a conventional fan speed control device.

Figure 2: Time curve of the DC drive voltage output by the conventional fan speed control device.

Fig. 3 is a circuit diagram showing a first embodiment of the fan speed control device of the present invention.

Fig. 4 is a timing chart showing the duty cycle ratio of the pulse width modulation signal outputted by the first embodiment of the fan speed control device of the present invention.

Figure 5: Electricity of the second embodiment of the fan speed control device of the present invention Road map.

Fig. 6 is a time chart showing the duty cycle ratio of the pulse width modulation signal outputted by the second embodiment of the fan speed control device of the present invention.

1. . . control unit

11. . . Voltage dividing circuit

111. . . High voltage end

112. . . Low voltage end

113. . . First voltage divider resistor

114. . . Second voltage dividing resistor

115. . . Tandem midpoint

12. . . Capacitor

2. . . Fan drive unit

twenty one. . . Working voltage input

twenty two. . . Control voltage input

twenty three. . . Drive signal output

C. . . Fan motor coil

Vs. . . DC voltage source

Vc. . . Control voltage

Claims (5)

A fan speed control method includes: generating a start pulse width modulation signal to a fan motor coil by a fan driving unit during a starting period; and generating a steady state by the fan driving unit after the starting period is completed The pulse width modulation signal is sent to the fan motor coil; wherein the duty cycle ratio of the start pulse width modulation signal is greater than a duty cycle ratio of the steady state pulse width modulation signal. The fan speed control method according to claim 1, wherein the fan driving unit is input with a control voltage that exhibits a single voltage value, and the length of the startup period is preset to the fan driving unit. The fan speed control method according to claim 1, wherein a control voltage having a starting voltage value and a steady voltage value is sequentially input to the fan driving unit, and the control voltage having the starting voltage value is The fan drive unit is input during the start period, and the control voltage having the steady state voltage value is input to the fan drive unit after the start of the start period. A fan speed control device includes: a control unit having a voltage dividing circuit and a capacitor, the voltage dividing circuit having a high voltage end, a low voltage end, and a series midpoint, the tandem midpoint Connecting the high voltage terminal via a first voltage dividing resistor and connecting the low voltage terminal via a second voltage dividing resistor, the capacitor being connected in parallel with the first voltage dividing resistor; a fan driving unit has a control voltage input end and a driving signal output end, the control voltage input end is connected to the serial connection midpoint, and the driving signal output end is connected to a fan motor coil to generate a start pulse width adjustment The variable signal and a steady-state pulse width modulation signal are sent to the fan motor coil; wherein a duty cycle ratio of the start pulse width modulation signal is greater than a duty cycle ratio of the steady state pulse width modulation signal. The fan speed control device according to claim 4, wherein the high voltage end of the voltage dividing circuit is connected to the DC voltage source, and the low voltage end of the voltage dividing circuit is grounded.