CN1893254A - Drive circuit of low-noise brush-less DC. fan - Google Patents
Drive circuit of low-noise brush-less DC. fan Download PDFInfo
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- CN1893254A CN1893254A CN 200510083217 CN200510083217A CN1893254A CN 1893254 A CN1893254 A CN 1893254A CN 200510083217 CN200510083217 CN 200510083217 CN 200510083217 A CN200510083217 A CN 200510083217A CN 1893254 A CN1893254 A CN 1893254A
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Abstract
The drive circuit converts Hall harmonic signal to a pulse width modulation signal changed following change of Hall harmonic signal. Comparing the pulse width modulation signal with external rotation control signal generates pulse width modulation signal including rotation control signal. Inputting pulse width modulation signal to pulse width modulation driver outputs pulse width modulation drive signal with changeable pulse width for controlling current direction of single winding for full bridge circuit under certain rotation control signal. The said outputted pulse width modulation drive signal reduces ripple of current signal in winding so as to become smooth signal of current waveform near to harmonic. The invention improves running noise of DC motor effectively.
Description
Technical field
The present invention refers to a kind of drive circuit that can effectively improve the Brushless DC motor of noise especially about a kind of Brushless DC motor fan drive circuit.
Background technology
Have single-phase full wave and two-phase half-wave that Brushless DC motor is common drive kenel for two kinds, at present in order to make Brushless DC motor have temperature control or to adjust the function of motor rotary speed easily, its drive IC mainly adopts the pulse-width modulation driver, please cooperate consult shown in Figure 4, be present a kind of Brushless DC motor drive circuit calcspar that adopts pulse-width modulation control rotating speed, it includes:
One pulse-width modulation driver 50, it includes a hall signal input, a PWM input, slow-speed of revolution setting end, a frequency produces output and a replacement is held, and its clock signal input connects the frequency of oscillation that an oscillating circuit 501 is exported tens K approximately;
One Smith's circuits for triggering 53, its output are connected to the hall signal input of this pulse-width modulation driver 50, and its input then connects for the Hall element (not shown);
One pins detecting and automatic starting circuit 54, is connected in the replacement end of these Smith's circuits for triggering 53, this oscillating circuit 501 and this pulse-width modulation driver 50; And
One full-bridge circuit 51 is connected between the output and unicoil 52 of this pulse-width modulation driver 50.
The said motor drive circuit mainly is converted to pulse wave signal by Smith's circuits for triggering 53 with the string wave output signal of Hall element, inputs to the hall signal input of this pulse-width modulation driver 50 again.This pulse-width modulation driver 50 is set the end input voltage according to the pwm signal and the slow-speed of revolution, judge that the control rotating speed is high or low, if pwm signal is set terminal voltage greater than the slow-speed of revolution, then representative control motor is high rotation speed operation, and then this pulse-width modulation driver can be according to the Hall square-wave signal, and control is to the PWM drive signal of the high pulsewidth of full-bridge circuit 51 outputs, order input unicoil 52 electric currents increase and improve rotating speed, otherwise, then turn down the PWM drive signal that exports full-bridge circuit to, to reduce rotating speed.
Please cooperate and consult shown in Fig. 5 A, B, the C, export the PWM drive signal and the coil current I of full-bridge circuit 51 for pulse-width modulation driver 50 to
LOscillogram, by among the figure can shown in as can be known owing to adopt PWM drive unicoil 53, so can cause coil current I
LWaveform is the sawtooth waveform of a big slope, and chain ripple phenomenon is quite serious, is easy to generate electronic noise when making motor running, and can reduce the Brushless DC motor reliability.
Because use the said PWM drive signal to control motor rotary speed easily as the drive signal of full-bridge circuit, but produced counter productive also, therefore, a kind of drive circuit of exporting trapezoidal pulsewidth drive signal is suggested, with the shortcoming of improvement PWM drive signal.See also shown in Fig. 6 A,, can make coil current I because the PWM drive signal is a pulse wave waveform
LThe slope of waveform is very big, for another example shown in Fig. 6 B, if the PWM drive signal is adjusted into trapezoidal drive signal, then can make coil current I
LThe waveform slope of signal slows down, and reduces chain ripple phenomenon.Only, this design still has its counter productive, even to change square-wave signal and be a trapezoidal signal, then its signal frequency can't be too high, and only, the frequency of the oscillating circuit of above-mentioned drive circuit is about tens K18-30KHz, can't form effective trapezoidal drive signal, therefore, if this trapezoidal drive signal will reach and the same rotating speed of PWM pulse wave drive signal, then need strengthen its electric current.In general, if will reach 4000 rotating speeds that change, above-mentioned drive circuit only needs about 300 milliamperes electric current, the electric current that this one drive circuit then will at least 350 milliamperes, and i.e. more power consumption under comparing, and running efficiency is also poor.
It seems all have its shortcoming to wait to improve by above-mentioned two kinds design of drive circuit of adopting pulse wave modulation control rotating speed.
Summary of the invention
For this reason, main purpose of the present invention provides a kind of low-noise brush-less DC fan driving circuit, adopts the drive signal of pulse-width modulation equally, but can make the coil circuit signal comparatively level and smooth, slow down the ripple phenomenon, the electronic noise when reducing motor running, the reliability of raising Brushless DC motor.
It is as follows to desire to reach the employed major technique means of above-mentioned purpose:
A kind of low-noise brush-less DC fan driving circuit, it includes:
One Hall pulse-width modulation signal generating circuit connects for Hall element, is a pulse-width modulation signal with Hall string ripple conversion of signals, makes the amplitude modulation of the pulsewidth of this pulse-width modulation signal with this Hall string ripple signal;
One rotating speed is judged signal generating circuit, is connected to the output of this Hall pulse-width modulation signal generating circuit, to compare with the PWM input signal, contains the pulse-width modulation signal of controlling rotating speed with output packet;
One pulse-width modulation driver, it includes a hall signal input, a SPWM (the sinusoidal pulse-width modulation of Sinusoidal Pulse width modulation) signal input part, is reset and held and frequency generation output; This pulse-width modulation driver can include one again and remove frequency input terminal, wherein this SPWM signal input part is connected to the output that this rotating speed is judged signal generating circuit, judges that by this rotating speed the pulse-width modulation signal of signal generating circuit output is adjusted the output pulse width drive signal; And
One full-bridge circuit is connected to this pulse-width modulation output end of driver, and with one only coil be connected;
Above-mentioned drive circuit is still possessed the design of pulse-width modulation control rotation speed of the fan, only for improving because the pulse-width modulation drive signal causes coil current to have tangible ripple phenomenon, the present invention mainly be with Hall string ripple conversion of signals one along with Hall string ripple signal change changes the pulse-width modulation signal, again this pulse-width modulation signal and outside speed controling signal are compared, to produce a pulse-width modulation signal that comprises speed controling signal, so, the pulse-width modulation drive signal that this pulse-width modulation driver promptly changes the full-bridge circuit output pulse width under a specific rotation speeds, the ripple phenomenon of coil current signal is slowed down, be a nearly string ripple than the smoothing current waveform signal, effectively improve the Brushless DC motor electronic noise in when running.
Description of drawings
Fig. 1 is the circuit block diagram of a preferred embodiment of the present invention.
Fig. 2 is a preferred embodiment circuit block diagram of the present invention's the 3rd comparison circuit.
Fig. 3 A, Fig. 3 B, Fig. 3 C are each point signal waveforms of the present invention.
Fig. 4 is the one drive circuit of the Brushless DC motor of prior art.
Fig. 5 A, Fig. 5 B, Fig. 5 C are the coil current oscillogram of Fig. 4 drive circuit under distinct pulse widths modulation drive signal.
Fig. 6 A, Fig. 6 B are the signal waveforms of the Brushless DC motor of prior art.
Symbol description among the figure:
10 Hall pulse-width modulation signal generating circuits
11 amplifying circuits
12 first comparison circuits
121 oscillating circuits
20 rotating speeds are judged signal generating circuit
21 second comparison circuits
22 the 3rd comparison circuits
221 integrating circuit
222 select amplifying circuit
223 comparators
30 pulse-width modulation drivers
31 full-bridge circuits
32 unicoils
33 Smith's circuits for triggering
34 pin detecting and automatic starting circuit
50 pulse-width modulation drivers
501 oscillating circuits
51 full-bridge circuits
52 unicoils
53 Smith's circuits for triggering
54 pin detecting and automatic starting circuit
Embodiment
At first see also shown in Figure 1ly, be the circuit block diagram of a preferred embodiment of Brushless DC motor drive circuit of the present invention, it consists predominantly of:
One Hall pulse-width modulation signal generating circuit 10, for Hall element connection not shown in the figures, Hall+/Hall-is converted to a pulse-width modulation signal with Hall string ripple signal, makes the amplitude modulation of the pulsewidth of this pulse-width modulation signal with this Hall string ripple signal;
One rotating speed is judged signal generating circuit 20, is connected to the output of this Hall pulse-width modulation signal generating circuit 10, compares with the pwm signal PWM I/P that uses with the external control rotating speed, contains the pulse-width modulation signal SPWM that controls rotating speed with output packet;
One pulse-width modulation driver 30, it includes a hall signal input, a SPWM signal input part, is reset and held and frequency generation output, this pulse-width modulation driver 30 can include one again except that frequency input terminal again, wherein this SPWM signal input part is connected to the output that this rotating speed is judged signal generating circuit 20, judges that by this rotating speed the pulse-width modulation signal SPWM of signal generating circuit 20 outputs adjusts the output pulse width drive signal; Again, this pulse-width modulation driver 30 includes a frequency eliminating circuit (not shown), its signal input part sees through amplifying circuit 10 outputs that Smith's circuits for triggering 33 are connected to this Hall pulse-width modulation signal generating circuit 10, its frequency elimination multiple selecting side is a frequency elimination selecting side, set the frequency elimination multiple of frequency eliminating circuit for setting different voltage quasi positions, the end of resetting then pins detecting and automatic starting circuit 34 for one, wherein this pinning detecting and automatic starting circuit 34 inputs connect the output of Smith's circuits for triggering 33 and oscillating circuit 121 respectively, to judge whether present motor running pins, if, this pulse-width modulation driver 30 of then resetting; And
One full-bridge circuit 31 is connected to the output of this pulse-width modulation driver 30, and with one only coil 32 be connected.
Above-mentioned Hall pulse-width modulation signal generating circuit 10 consists predominantly of:
One amplifying circuit 11, the output Hall+/Hall-of connection Hall element is to be amplified Hall string ripple signal back output; And
One first comparison circuit 12, one input end is connected with amplifying circuit 11, another input then is connected to the output of an oscillating circuit 121, first comparison circuit 12 is compared the Hall string ripple signal of amplification and the oscillator signal of this fixed frequency, export a pulse-width modulation signal that changes along with Hall string ripple signal amplitude.Because first comparison circuit 12 is in order to be a pulse wave signal with Hall string ripple conversion of signals, so can use the comparator of being made up of operational amplifier.
Above-mentioned rotating speed judges that signal generating circuit 20 then consists predominantly of:
One second comparison circuit 21, wherein an input is connected to the output of first comparison circuit 12, and its output then is connected to the SPWM signal input part of this pulse-width modulation driver 30; And
One the 3rd comparison circuit 22, its input connects the output of oscillating circuit 121 respectively, one control rotating speed connects with a pwm signal PWM I/P and a slow-speed of revolution setting signal Low SpeedSet, be higher or lower than slow-speed of revolution setting signal with decision control rotating speed with pwm signal, again, the output of the 3rd comparison circuit 22 is connected to another input of second comparator 21, compare with pulse-width modulation signal with 12 outputs of first comparison circuit, to determine controlling rotating speed SPWM signal at last, again it is inputed to the SPWM signal input part of this pulse wave width modulation driver 30.
Because first comparison circuit 12 and the 3rd comparison circuit 22 are all exported pulse wave signal, so this second comparison circuit 21 is a NAND logical circuit, and wherein the 3rd comparison circuit 22 is in order to judge pwm signal and slow-speed of revolution setting signal, and this slow-speed of revolution setting signal is generally a voltage quasi position, please cooperate and consult shown in Figure 2ly, this one the 3rd comparison circuit 22 includes:
One integrating circuit 221 is converted to direct current quasi-position with the PWM pulse width signal;
One selects amplifying circuit 222, and its input connects this integrating circuit 221 respectively and slow-speed of revolution setting signal connects, and amplifies back output to judge the accurate high person in position between the two; And
One comparator 223, its input connect the output of this selection amplifying circuit 222 and the output of oscillating circuit 121 respectively, with selecting amplifying circuit 222 to select the accurate position of direct current of output to be converted to pwm signal, input to second comparison circuit 21 again.
Preceding announcement Hall pulse-width modulation signal generating circuit 10, rotating speed judge that signal generating circuit 20, pulse-width modulation driver 30, full-bridge circuit 31 and pinning detecting and automatic starting circuit 34 can be integrated into an integrated circuit component.
See also shown in Fig. 3 A～C, difference circuit each point oscillogram of the present invention, by among the figure as can be known, the main elder generation of the present invention compares the triangular signal of Hall string ripple signal and oscillating circuit, obtain a pulse-width modulation signal because triangular signal amplitude and frequency are all fixing, so its arteries and veins changes along with Hall string ripple signal change, again this pulse-width modulation signal and outside rotating speed control pwm signal are compared, to produce a pulse-width modulation signal that comprises speed controling signal, shown in Fig. 3 B, when the suitable control output end of this pulse-width modulation driver is exported as Fig. 3 C drive signal waveform, coil current I
LWaveform, the comparatively smooth waveform that can present a nearly string ripple, if increase rotating speed when the pulsewidth of outside speed controling signal strengthens, then current waveform can be more near string ripple signal, make the ripple phenomenon effectively be improved, anticipate promptly that the present invention is comparatively level and smooth because of current signal when running, few electronic noise so can effectively go out, and be the Brushless DC motor drive circuit of a low noise.
As shown in the above description, the present invention adopts the pulse-width modulation mode to control the rotating speed of Brushless DC motor equally, but the present invention makes the unicoil current waveform be improved by adding the pulse-width modulation hall signal, and effectively slow down the ripple phenomenon, make motor have low noise running effect.
Claims (10)
1. a low-noise brush-less DC fan driving circuit is characterized in that, includes:
One Hall pulse-width modulation signal generating circuit connects for Hall element, is a pulse-width modulation signal with Hall string ripple conversion of signals, makes the amplitude modulation of the pulsewidth of this pulse-width modulation signal with this Hall string ripple signal;
One rotating speed is judged signal generating circuit, is connected to the output of this Hall pulse-width modulation signal generating circuit, to compare with the PWM input signal, contains the pulse-width modulation signal of controlling rotating speed with output packet;
One pulse-width modulation driver, it includes a hall signal input and a SPWM signal input part, this pulse-width modulation driver can include one again and remove frequency input terminal, wherein this SPWM signal input part is connected to the output that this rotating speed is judged signal generating circuit, judges that by this rotating speed the pulse-width modulation signal of signal generating circuit output is adjusted the output pulse width drive signal; And
One full-bridge circuit is connected to this pulse-width modulation output end of driver, and is connected with a unicoil.
2. low-noise brush-less DC fan driving circuit as claimed in claim 1 is characterized in that, this Hall pulse-width modulation signal generating circuit consists predominantly of:
One amplifying circuit, the output of connection Hall element is to be amplified Hall string ripple signal back output; And
One first comparison circuit, one input end is connected with amplifying circuit, another input then is connected to the output of an oscillating circuit, and first comparison circuit is compared a Hall string ripple signal and a reference voltage that amplifies, and exports a pulse-width modulation signal that changes along with Hall string ripple signal amplitude.Because first comparison circuit is in order to be a pulse wave signal with Hall string ripple conversion of signals, so can use the comparator of being made up of operational amplifier.
3. low-noise brush-less DC fan driving circuit as claimed in claim 1 or 2 is characterized in that, this rotating speed decision circuitry consists predominantly of:
One second comparison circuit, wherein an input is connected to the output of first comparison circuit, and its output then is connected to the pwm signal input of this pulse-width modulation driver; And
One the 3rd comparison circuit, output, a control rotating speed that its input connects oscillating circuit respectively connect with a pwm signal and a slow-speed of revolution setting signal, be higher or lower than slow-speed of revolution setting signal with decision control rotating speed with pwm signal, again, the output of the 3rd comparison circuit is connected to another input of second comparator, compare with pulse-width modulation signal with the output of first comparison circuit, to determine the controlling rotating speed pwm signal at last, again it is inputed to the pwm signal input of this pulse wave width modulation driver.
4. low-noise brush-less DC fan driving circuit as claimed in claim 3 is characterized in that, the 3rd comparison circuit includes:
One integrating circuit is converted to direct current quasi-position with the PWM pulse width signal;
One selects amplifying circuit, and its input connects this integrating circuit respectively and slow-speed of revolution setting signal connects, and amplifies back output to judge the accurate high person in position between the two; And
One comparator, its input connect the output of this selection amplifying circuit and the output of oscillating circuit respectively, and the accurate position of the direct current after amplifying is converted to the PWM pulse width signal, input to second comparison circuit again.
5. low-noise brush-less DC fan driving circuit as claimed in claim 2 is characterized in that, this first comparison circuit is a comparator.
6. low-noise brush-less DC fan driving circuit as claimed in claim 3 is characterized in that, this first comparison circuit is a comparator.
7. low-noise brush-less DC fan driving circuit as claimed in claim 3 is characterized in that, this second comparison circuit is a NAND logical circuit.
8. low-noise brush-less DC fan driving circuit as claimed in claim 1, it is characterized in that, this pulse-width modulation driver one is reset and is held and frequency generation output, and in a frequency eliminating circuit is arranged, its signal input part sees through the amplification circuit output end that Smith's circuits for triggering are connected to this Hall pulse-width modulation signal generating circuit, the frequency elimination multiple selecting side of this frequency eliminating circuit is a frequency elimination selecting side, sets the frequency elimination multiple of frequency eliminating circuit for setting different voltage quasi positions.
9. low-noise brush-less DC fan driving circuit as claimed in claim 8 is characterized in that, the replacement end of this pulse-width modulation driver connects one and pins detecting and automatic starting circuit, and its input connects the output of Smith's circuits for triggering and oscillating circuit respectively.
10. low-noise brush-less DC fan driving circuit as claimed in claim 8, it is characterized in that this Hall pulse-width modulation signal generating circuit, rotating speed judge that signal generating circuit, pulse-width modulation driver, full-bridge circuit and pinning detecting and automatic starting circuit are integrated into an integrated circuit component.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2005100832174A CN100397775C (en) | 2005-07-07 | 2005-07-07 | Drive circuit of low-noise brush-less DC. fan |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2005100832174A CN100397775C (en) | 2005-07-07 | 2005-07-07 | Drive circuit of low-noise brush-less DC. fan |
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| Publication Number | Publication Date |
|---|---|
| CN1893254A true CN1893254A (en) | 2007-01-10 |
| CN100397775C CN100397775C (en) | 2008-06-25 |
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| Application Number | Title | Priority Date | Filing Date |
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| CNB2005100832174A Expired - Fee Related CN100397775C (en) | 2005-07-07 | 2005-07-07 | Drive circuit of low-noise brush-less DC. fan |
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| CN (1) | CN100397775C (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102545770A (en) * | 2010-12-30 | 2012-07-04 | 晶致半导体股份有限公司 | Motor driving module capable of adjusting output pulse width modulation control signal |
| CN101796716B (en) * | 2007-10-23 | 2013-02-20 | 罗姆股份有限公司 | Motor drive circuit, method, and cooling device using the same |
| CN103560743A (en) * | 2013-10-23 | 2014-02-05 | 国家电网公司 | Method and device for detecting rotating speed of motor |
| CN104993744A (en) * | 2015-07-30 | 2015-10-21 | 成都芯进电子有限公司 | Single-coil direct-current brushless motor driving integrated circuit driven by sine wave current |
| CN105703671A (en) * | 2016-01-19 | 2016-06-22 | 亚翌斯风电机(上海)有限公司 | DC brushless fan motor driving circuit of double low-noise operational amplifier |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2375030Y (en) * | 1998-07-23 | 2000-04-19 | 点晶科技股份有限公司 | D. C. brushless fan driving circuit |
-
2005
- 2005-07-07 CN CNB2005100832174A patent/CN100397775C/en not_active Expired - Fee Related
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101796716B (en) * | 2007-10-23 | 2013-02-20 | 罗姆股份有限公司 | Motor drive circuit, method, and cooling device using the same |
| CN102545770A (en) * | 2010-12-30 | 2012-07-04 | 晶致半导体股份有限公司 | Motor driving module capable of adjusting output pulse width modulation control signal |
| CN102545770B (en) * | 2010-12-30 | 2014-10-08 | 晶致半导体股份有限公司 | Motor driving module capable of adjusting output pulse width modulation control signal |
| CN103560743A (en) * | 2013-10-23 | 2014-02-05 | 国家电网公司 | Method and device for detecting rotating speed of motor |
| CN103560743B (en) * | 2013-10-23 | 2016-04-20 | 国家电网公司 | Application of Motor Speed Detecting method and apparatus |
| CN104993744A (en) * | 2015-07-30 | 2015-10-21 | 成都芯进电子有限公司 | Single-coil direct-current brushless motor driving integrated circuit driven by sine wave current |
| CN104993744B (en) * | 2015-07-30 | 2018-04-13 | 成都芯进电子有限公司 | The unicoil driven by Brush-Less DC motor integrated circuit of sine-wave current driving |
| CN105703671A (en) * | 2016-01-19 | 2016-06-22 | 亚翌斯风电机(上海)有限公司 | DC brushless fan motor driving circuit of double low-noise operational amplifier |
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| Publication number | Publication date |
|---|---|
| CN100397775C (en) | 2008-06-25 |
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Assignee: Xiexi Micro-Electromechanical Technology (Kunshan) Co., Ltd. Assignor: Xiexi Motor Co., Ltd. Contract record no.: 2010990000273 Denomination of invention: Drive circuit of low-noise brush-less DC. fan Granted publication date: 20080625 License type: Exclusive License Open date: 20070110 Record date: 20100512 |
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