JPS63198594A - Motor drive circuit - Google Patents

Abstract

PURPOSE:To miniaturize a motor, by discriminating the fluctuation of the detecting output of a sensor with a discriminating means and by conducting coils in a designated timing corresponding to the phase of motor decided by the discriminated fluctuation and the detecting output of the sensor. CONSTITUTION:A Hall sensor 10 generates the voltage in compliance with the rotor position of a three-phase brushless motor 50. A discriminating means 20 is provided. On the basis of the size of output value of two Hall sensors 10 continuously obtained with this discriminating means 20, it is discriminated whether the output value of the Hall sensor 10 tends to increase or decrease. A ROM is used for a conductive timing setting means 30. With the discriminated result by the discriminating means 20 and the output of the Hall sensor 10 the drive command signal is outputted to a driver 40 to drive the motor 50. Now that the current is to be conducting through coils in a designated timing, a single piece of sensor can detect the motor position.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention relates to a drive circuit for a brushless motor that controls energization using a sensor such as a Hall sensor for position detection.

[Prior Art] Conventionally, there has been known a drive circuit that controls energization using a Hall sensor to detect the position of a brushless motor. In this drive circuit, each coil forming the motor is provided with a Hall sensor for position detection, and the timing of energization of the coil is determined in accordance with the detection output.

Furthermore, as devices become smaller, brushless motors themselves are also becoming smaller. However, as brushless motors become smaller, the space for installing Hall sensors is limited, making it easy for errors to occur in positioning the sensor.
Another drawback is that the Hall sensor does not necessarily output accurate motor phase (rotor position) due to interference between the coils. Therefore, there is a problem that it is difficult to downsize the brushless motor.

[Problems to be solved by the invention J Therefore, the purpose of the present invention is to solve such problems,
An object of the present invention is to provide a motor control device that can further reduce the size of a motor.

[Means for Solving the Problems] In order to achieve such an object, the present invention provides a determination means for determining an increase/decrease state of the detection output of the sensor in a motor drive circuit having a sensor for position detection. and means for setting the energization timing of each coil in the motor in accordance with the phase of the motor determined from the detection output of the sensor and the determination result by the determination means.

[Function 1] The present invention determines the increase/decrease state of the detected output of the sensor by a determining means, and energizes the coil at a timing corresponding to the phase of the motor determined by the determined increase/decrease state and the detected output of the sensor. Therefore, the position of the motor can be detected with one sensor.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

In this embodiment, a three-phase brushless motor will be described as an example.

FIG. 1 shows an example of a configuration in an embodiment of the present invention.

In FIG. 1, reference numeral 10 denotes a Hall sensor that converts magnetism into current, and the Hall sensor 10 generates a voltage depending on the position of the rotor of the motor 50. One Hall sensor 10 is provided in the motor 50.

Reference numeral 20 denotes a determining means, and the determining means 20 determines whether the output value of the Hall sensor 10 is increasing or decreasing based on the magnitude of the successively obtained output values of the two Hall sensors 10.

Reference numeral 30 denotes an energization timing setting means, and the energization timing setting means 30 uses a read-only memory 'J (ROM), and stores a drive instruction signal according to the phase. The energization timing setting means 30 is the determining means 20.
When the determination result and the output of the Hall sensor IO are input, a drive instruction signal corresponding to the phase determined by this input signal is output to the driver 40.

Reference numeral 40 denotes a driver for driving the motor 50, and the driver 40 supplies a driving current to each coil of the motor 50 in response to an energization instruction signal.

FIG. 2 shows an example of a detailed circuit configuration in an embodiment of the present invention.

In FIG. 2, FFo NFF5 is a JK type rough flip-flop, and DFFo and DFF+ are D type flip-flops. DEC is a decoder, and decoder DE
C performs control processing from starting to stopping the motor 50, which will be described later. ADC is an analog-to-digital (80) converter.

GOMP is the magnitude comparator and RO
M is read-only memory. Memory ROM
issues driving instructions to drivers DRO to OR. COU
is a counter, and DRo to DR2 are drivers.

NDo~NO+s is Nantes Gate, 80. -AD
7 is an and gate. ORO to OR7 are OR gates, No to N are inverters, op, ;o
p, is an op anti, and ZD is a zener diode. R0 to R13 are resistors, and Go'''C2 is a capacitor.

Xtal is an oscillator, and H5 is a Hall sensor for detecting the position of the motor. SW is a switch for starting the motor, Te5t is a switch for testing, ccw-c
w is a rotation direction changeover switch, and A-B-C are each coil of the three-phase brushless motor 50.

Inverter N0, resistor R0, and capacitor 00 form an initial value setting circuit 2-1. Inverter N, oscillator X
tal, resistor R8, capacitors C3 and C2 form an oscillation circuit 2-2. When a power supply (not shown) is supplied, the oscillation circuit 2-2 starts oscillating, and a stable clock signal at the oscillation frequency of the oscillator Xtal is supplied to the clock terminals of each part of the circuit.

On the other hand, the initial value setting circuit (hereinafter abbreviated as puc) 2-1 also operates, and the inverter N is turned on for a time constant determined by the resistor R0 and capacitor 〇〇. A PUC pulse is generated. This P
The uC pulse is applied to the reset (R) terminals of the JK type flip-flops FFO to FF2 to reset each flip-flop.

Therefore, all the Q outputs of flip-flops FFO to FF2 become "0", and this "0" output is sent to the decoder DE.
A-8-[: of C is input, and only the CCO terminal output is selected. The output of this terminal CCO is input to the Rfili terminal of flip-flop FF3, and is input to the flip-flop F
F is reset to set the initial value of the circuit.

Next, the constant voltage circuit 2-3 and the differential amplifier circuit 2-4 will be explained.

Operational amplifier OPO, resistor R6, Zener diode ZD
forms a constant voltage circuit 2-3, and a Zener diode ZD
Outputs a constant voltage determined by

Further, the operational amplifier OPI and the resistors R7 to RI3 form a differential amplifier circuit 2-4, which amplifies the output of the Hall sensor H5 for detecting the position of the brushless motor 50. moreover,
Gain adjustment is performed by resistor R1.

Flip-flops DFFo, OFF+, FFs and comparator COMP form a differential circuit.

Next, the operation of this embodiment will be explained based on FIGS. 3 and 4.

(Step SO) Initial setting: CCO terminal output selection When the power is turned on, flip-flops FFo to FFI are reset and the CCO terminal output of the decoder DEC is selected. Then, when the test switch Test t is turned on and the start switch SW is turned on, the NAND gate NDA outputs a signal "0", and this signal "0" is sent to the J of the flip-flop FF2 via the NAND gate NO, 3. Flip-flop FF2 is manually set to the terminal.

The Q outputs of flip-flops FF2 to FFO are connected to terminals "'1", "0", and 0" in synchronization with the clock signal, respectively.
Then, the state moves to the GCI output state of step SL.

(Step St) Gain adjustment: C (: The output signal of the selected output CCI terminal of the l terminal sets the AD converter ADO to a convertible state via the OR gate OR8 and the Nant gate ND+s. The output signal of the CC1 terminal is D-type flip-flop DFFo through gate ADI
- Sent to 0FFI.

Since this output signal becomes a switch instruction signal, the output result of the D converter ADC is latched in the flip-flop DFFO. Further, the output result of the flip-flop DFFO is latched into the flip-flop OFF.

At this time, in order to ensure that the digitally converted output value of the Hall sensor H5 falls within a predetermined range, the maximum and minimum output values are changed to Q1 to Q4 of the D-type flip-flop DFFO.
While monitoring the output, adjust the OPI resistor RI3 of the differential amplifier 2-4. In this way, the gain of the amplifier 2-4 can be adjusted to normalize the Hall sensor output so that it falls within a predetermined range. At this point, the start switch is turned off to return to the initial state of step SO.

(Step 52) Start driving the motor: Selected output of terminal CC2 Next, turn off the test switch Te5t, turn on the start switch SW again, and the sequence (control circuit)
starts running, and a series of control operations related to driving the motor 60 are performed.

The CCO terminal output of the decoder DEC is "1", the inverter N4 output is "1", and furthermore, when the SW is turned on, the inverter N2 output "1" is input to the Nantes gate NDo. Therefore, "O" is output from the Nantes gate NDo.

Then, the "1" output is input to the J terminal of the flip-flop FFO via the Nant gates ND, , and the flip-flop FFO is set.

Since the outputs of the flip-flops FF, FF remain "0", the outputs of the flip-flops Fh to FF become "0", "O", and "1", respectively, and the outputs of the flip-flops Fh to FF become "0", "O", and "1", respectively, and the outputs of the flip-flops Fh to FF become "0", "O", and "1", respectively. C, and in step S2 CC
Only 2 outputs are selected.

The output of this terminal CC2 is input to the Nant gate ND1B via the OR gate OR. At the same time, the Nant gate ND+o when moving from the terminal CCO output to the terminal CC2 output
The output pulse of counter C is passed through OR gate Ono.
Reset Ou.

Then, the Q1 output of the counter COU is the Nantes gate N
[), , to set the AD converter ADC to write mode.

Then, the differential amplified output of Hall sensor H5 is transferred to converter A.
A CD is input and the analog differential amplification output is converted into a digital value. Furthermore, the output of the AND gate AD+ is input to the CLK terminal of the D-type flip-flop DFFO/DFF, and the converted data is sent to the D-type flip-flop DFF.
o, latched at OFF+.

Then, when the Q4 output "1" of the counter COU is inputted to the J terminal of the flip-flop FF via the AND gate ADO, the flip-flop FF is set.

Then, each output of flip-flops FF2 to FFO becomes 0", "1", and 1", respectively, and decoder D
Only the terminal CG3 output is selected by manual input to the EC.

(Step S3) Energization from coil A to coil B: Select output of terminal CC3 The output of terminal CC3 is manually applied to the U terminal of driver DRo via OR gate OR8, and on the other hand, OR gate OR8
A current flows from the A coil of the three-phase motor to the B coil of the three-phase motor by applying manual power to the Di4 child of the driver DRI via the .

At this time, when the motor 50 starts rotating by energizing the coils A and B, the Hall sensor Is for position detection
The output value of changes. This output value is ^D converter AD
It is input to C and converted into a 4-bit digital value by AD converter A[lC.

Since the D-type flip-flops DFFo, DFF+ have already been set, this digital conversion value is stored in the D-type flip-flops DFFo, OFF+ from time to time. Then, the comparator COMP detects the magnitude of the current digital value stored in the flip-flop DFFO and the digital value stored in the flip-flop DFF1 before a fixed time. Based on this detection result, it can be determined whether this digital value is on an increasing trend, decreasing trend, or unchanged.

In addition, when the digital value does not change, the Hall sensor H5
when the output of the motor is at its peak or when the motor rotor is not rotating. In other words, Combare Yu GOMP
As a result of the comparison, the flip-flop is turned off.

When the output X<output Y1 of the flip-flop DFF0 or vice versa, it is determined that the rotor of the motor 50 is rotating, and the process proceeds to the motor drive control process of step S6.

This instruction indicates that the comparison result of comparator COMP is terminal C,
, C, to Nantes gate ND via OR gate OR2
0” is output to ♂, and this signal is output to Nant gate ND, 3
The flip-flop FF2 is manually set to the J terminal of the flip-flop FF2 via the terminal.

Therefore, flip-flop FF2 ・FF, ・F
F and become 1", "1", and 1", respectively, and the process moves to the CCa terminal output state in step S6.

On the other hand, if the Hall sensor output value does not change within a certain period of time, that is, when the output Y of the flip-flop DFFO = the output X of the flip-flop DFF, the rotor is stopped or the phase peak of the Hall sensor H5 is reached. Therefore, the process proceeds to the next step S4 and switches the coil to be energized. This step movement instruction is given by the comparator COMP.
A signal is output from the C3 terminal of the Nant gate ND3, which outputs "0", and this signal is input to the Nant gate ND3.
, , to the terminal of the flip-flop FFO to reset the flip-flop FF.

Therefore, flip-flop FF2 ・FF, -FF
The Q output of 0 is “0”, “1”, “O” respectively.
It is input to the next decoder DEC and CC in step S4 is inputted to the decoder DEC.
4 @ Only dry output is selected. Also, Nantes Gate ND,
, the pulse of counter CO through OR gate OR0
Manually connect the R terminal of U to reset the counter COU.

(Step S4) Energization from coil A to coil C: Selected output of terminal CC4 The CC4 terminal output is input to the U terminal of driver DR, via OR gate OR3, and is also input to D of driver R2 via OR gate OR. When power is applied to the terminal, current flows from the A coil to the C coil of the three-phase motor.

As described above, when the rotor starts rotating by energizing the motor 50, the output value of the Hall sensor H5 for position detection changes. A detection signal is output from the CI terminal or the C8 terminal when the increase or decrease is detected by the comparator COMP.

This detection signal is input to the Nandt gate ND via the OR gate OR, and the J terminal of the flip-flop FFO is input to the NAND gate via the NANDIO, and the Q output of the flip-flop FF2 is set to 1 via the Nant gate No.
・It becomes “1”・1” and only the CC6 output is selected from the decoder DEC.

On the other hand, if the Hall sensor output value does not change within a certain period of time, a signal is output from the C2 terminal of the comparator COMP, inputted to the Nant gate ND6, and input to the Nant gate NO, .
is input to the Jfli child of flip-flop FF2 via . Therefore, the Q outputs of the flip-flops FF2 to FFO are "1", "1", and "O'", respectively, and the output of the decoder DEC selects only CC5.

In addition, the pulse of the Nant gate NDIs is OR gate OR
0 to the R terminal of the counter COO to reset the counter COU.

(Step S5) Energization from coil B to coil C: Selected output of terminal CC5 The CC5 terminal output is inputted to the U terminal of the driver ORI via the OR gate OR7 and the D terminal of the driver DR2 via the OR gate OR7. Current flows from the B coil to the C coil of the phase motor.

As described above, when the motor starts rotating by energizing it, the output value of the Hall sensor H5 for position detection changes.

An increase or decrease is detected by the comparator COMP and a detection signal is outputted from the CI terminal or the C8 terminal. This detection signal is passed through the OR gate OR2 to the Nantes gate ND.
2, enter Nantes Gate NO. It is input to the J#4 child of flip-flop FFO via .

Therefore, the Q outputs of flip-flops FF2 to FF are "1", "1", and "1'", respectively, and only the CC6 output is selected from the decoder DEC.

On the other hand, if the Hall sensor output value does not change within a certain period of time, a detection signal is output from the C2 terminal of the comparator COMP.

This detection signal is input to the Nant's gate NDS, the R terminal of the flip-flop FF via the Nant's gate ND, 2, and the flip-flop FF via the Nant's gate NO, 4.
, manually apply power to the R terminal of .

Therefore, the Q outputs of flip-flops FF and ~FFO are 0'', ``ON'', and ``ON'', respectively, and the decoder D
As the EC output, only the terminal CCO output is selected.

If the start switch SW remains on, the above-described operating procedure is repeated again. Above, the output value of the Hall sensor is
It is symmetrical with respect to its phase of 90°, and its phase is 270°.
Since they are symmetrical with respect to °, CC3, CC4, CC5
The absolute phase of the coil can be determined by detecting the slope of the output through the following states.

(Step Sa) Energization control: Selected output of terminal CC6 From each state of CC3, CC4, and CCS described above to CC6,
Here, the memory ROM is used to control energization of each coil of the three-phase motor.

The output value of the Hall sensor H5 is converted into a digital value by the AD converter ADO, and the output value is converted to a digital value by the D-type flip-flop DFF.
Latch to G. This latch output is a read-only memory (hereinafter referred to as RO) that stores the timing of energization control.
(abbreviated as M) is connected to the lower address 80~^.

The result of detecting whether the output of the Hall sensor H5 is increasing or decreasing by the comparator COMP is stored in the JK type flip-flop FF3.

If the output Y of the D-type flip-flop DFFO is larger than the output X of the D-type flip-flop OFF, the output of the Hall sensor H5 is in an increasing state, and the comparator COMP
"1'" is output from the C5 terminal of the JK type rough flip-flop, and the output signal is reset. Therefore, "0" is input to the ROM address ^4.

On the other hand, if the output Y of the D-type flip-flop DFFa is smaller than the output X of the D-type flip-flop DFFI, the output of the Hall sensor H5 is in a decreasing state, and the comparator CO
"1" is output from the C1 terminal of MP, inputted to the J terminal of JK type flip-flop FF3, and then output from the flip-flop FF.
Set 3. Therefore, the memory ROM address ^
“1” is input to 4.

As shown in FIG. 5, the output of the Hall sensor H5 is symmetrical with respect to the peak phase 9G'/270°. Therefore, the absolute phase of the output value can be determined from the state of increase or decrease of the output value of the Hall sensor H3 and the output value of the Hall sensor H5.In the present invention, the memory ROM is configured according to this absolute phase. Signals for instructing energization to each coil are stored in advance.

Then, an address instruction (absolute phase instruction) of the memory ROM is performed using the output of the Hall sensor BS and a signal representing an increase/decrease in this output, and the coils to be energized until the next address instruction is given are instructed to each driver DRO to DR2. This is how it was done.

The instruction to energize the memory ROM will be explained according to the time chart shown in FIG.

In Fig. 5, in this embodiment, the operational amplifier OP amplifies the Hall sensor output value, converts the output into a digital value, and performs conversion to 〇 while sampling at times jo, j+, jz, ... ing. Now time t0
From 1. When the digital conversion value is in an increasing state, the flip-flop FF is reset, but since the @ value becomes "1", the flip-flop FF3 is reset.

Then, the digital value at time t is input to the lower 4 bits of the address of the memory ROM, and the ROM data D0 at that time is input.
~D, is output. The data Do of the memory ROM is sent to the AND gate ^D2, and the data D of the memory ROM is sent to the AND gate ^D2.

goes to AND gate AD, data D2 of memory ROM goes to AND gate AD4, data 0 of memory ROM goes to AND gate AD4. is input to the AND gate ^DS, the data o4 of the memory ROM is input to the AND gate ^D6, and the data D of the memory ROM is input to the AND gate ^07.

The terminal CC6 output is selected from the decoder DEC. Therefore, the output of the terminal CC6 is input to the other terminals of the AND gates ADZ to AD7.

For example, as shown in FIG. 5, when the output from the Hall sensor H5 corresponds to time t1, the memory R corresponding to this output
Only OM data D0 and D3 output “1”, and the others output “O”.
When the memory contents are set to output "1", the AND gate ^D2 outputs "1" and inputs it to the U terminal of the driver 〇Ro via the OR gate OR.

Further, the AND gate ^OS outputs "1" and inputs it to the D terminal of the driver OR via the OR gate OR. Therefore, current flows from coil A to coil B of the three-phase motor.

Next, at time t6, since the output value of the Hall sensor H5 is in a decreasing state, the J type flip-flop FF is set, and the Q output of the JK type flip-flop FF3 becomes "1'". Therefore, the Hall sensor output value at time t6 is input to the lower 4 bits of the address of the memory ROM, and the Q output "1" of the flip-flop FF, which indicates the decreasing state.
'' is input to address A4 of the memory ROM.

At this time, the memory contents are set so that the data output of the memory ROM is "1" only for 02 and O6 and "0" for the others. As a result, data 02 in the memory ROM is input to the U terminal of the driver RI via the AND gate AD4 and the OR gate ORB. Also, ROM data 0. is an anime game)'AD? , is input to the D terminal of the driver DR2 via the OR gate OR, and the coil B of the three-phase motor is
Current flows from to coil C.

As described above, the present invention converts the Hall sensor output value into digital data, and detects the slope of the Hall sensor output value by taking the difference between this value and the value one sampling ago.

Also, since this digital value and the tilt detection signal are input as the ROM address, one Hall sensor H
It is possible to control energization switching to the three-phase motor coil from the output of No. 5.

Also, the on/off signal of the rotation direction changeover switch ccw-cw is input to the ROM address A, and the R
OM data is stored in reverse order. To stop the rotation of the motor 60, turn off the start switch SW, and the output of the CC7 terminal of the decoder I)EC will be selected, and this output signal will be input to the D@ terminal of each driver, so the rotation of the motor will be stopped. Stop.

Other Embodiments In the above-mentioned embodiment, phase detection was performed by digitally processing the output of the Hall sensor H5 using the ^/D converter ^DC, but Fig. 6 shows another embodiment in which phase detection is performed using an analog circuit. This will be explained with reference to FIG.

In this embodiment, the amplified result of the Hall sensor Its output is
As shown in FIG. 7, Vl, V2. By comparing the three-value levels of Vs, it is determined which of the above-mentioned levels the output level of the Hall sensor H5 is at, and the motor coil to be energized is designated.

In FIG. 6, the comparison results are sent to the decoder DECI by the level comparators CP0 to CP2. input to the A-B-C terminals of the operational amplifier 0P10. A differential circuit constituted by a resistor R and a capacitor C detects the slope of the output of the Hall sensor H5. The result is input to the D terminal of the decoder DE (+o), and the rotation direction changeover switch CCW-CW is input to the E terminal of the decoder DE (:,.). From this information, the signal to be phase-converted is input. It is also possible to send the signal from the decoder DEC+o to each driver (not shown) to control coil energization switching.

Although the Hall element is used as a sensor in this embodiment, it goes without saying that other magnetic sensors or optical sensors may be used as long as they can obtain a detection output that corresponds to the rotation angle of the rotor.

[Effects of the Invention] As explained above, according to the present invention, since only one Hall sensor is used, the motor can be downsized and the load when attaching parts is drastically reduced. Furthermore, the motor control circuit has the greatest advantage of being compatible with all multi-phase brushless motors by simply changing the contents of the ROM that performs phase conversion.

Furthermore, since the number of parts is small and adjustments are required, a significant cost reduction can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of a configuration in an embodiment of the present invention, FIG. 2 is a circuit diagram showing an example of a detailed circuit configuration in an embodiment of the present invention, and FIG. 3 is a processing of the decoder DEC in an embodiment of the present invention. FIG. 4, a functional block diagram showing an example of the contents, shows flip-flops FF0 to FF corresponding to the processing contents of the decoder DEC in the embodiment of the present invention. 5 is a timing chart showing the waveforms of each part in the embodiment of the present invention, FIG. 6 is a circuit diagram showing an example of the configuration in the second embodiment of the present invention, and FIG. 7 is an embodiment of the present invention. FIG. 3 is an explanatory diagram showing phase detection levels in FIG. H5...Hall sensor, ADC...A/D converter, DFFo~OFF,...D flip-flop, FF
,~FF,...JK type rough flip-flop ROM...
・Read-on memory, DRo"=OR2" driver. Block diagram of the embodiment of the present invention Fig. 1 Fig. 2 (part 3) Circuit diagram of the embodiment of the bundle 2 of the present invention Fig. 6 -〉〉〉

Claims (1)

[Scope of Claims] 1) In a motor drive circuit having a sensor for position detection, a determination means for determining an increase/decrease state of a detection output of the sensor; a detection output of the sensor and a determination result by the determination means; A motor drive circuit comprising means for setting energization timing of each coil in the motor according to a phase of the motor determined from the following. 2) The setting means is a memory that stores in advance the energization timing for each coil according to the phase, and the address of the memory is determined from the sampled detection output of the sensor and the determination result by the determination means. The motor drive circuit according to claim 1, characterized in that: