JPH0916275A - Driving control circuit - Google Patents

Abstract

PURPOSE: To improve the driving control circuit which drives and controls a motor used for a vacuum cleaner by controlling the phase of an AC voltage by using a thyristor. CONSTITUTION: The driving control circuit is stored previously with two potentials that 1st and 2nd potentials Va and Vb match, and has a table where the timing where a switching element TH11 turns ON is assigned to divided voltages Vmax to Vmin obtained by dividing potentials between the two points in plural stages and also has a control part 14 which detect the 1st and 2nd potentials Va and Vb at all times, collates the 1st and 2nd potentials Va and Vb when the 1st and 2nd potentials Va and Vb actually match with the divided voltages Vmax to Vmini in the table to determine the ON timing of the switching element TH11, and turns ON the switching element TH11 in the timing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive control circuit, and more particularly to an improvement of a drive control circuit for driving and controlling a motor used in a cleaner or the like by controlling the phase of an AC voltage using a thyristor. .

[0002]

2. Description of the Related Art A drive control circuit according to a conventional example will be described below with reference to the drawings. The drive control circuit according to the conventional example determines the rotation speed of a motor used for a vacuum cleaner,
It is a circuit that is adjusted by phase control. This circuit is shown in Figure 4.
As shown in, the AC power supply (1), the phase adjustment circuit (2),
The phase adjustment circuit (2) has a trigger circuit (3), a thyristor (TH1) and a bridge circuit (B1), and performs ON / OFF operation of the thyristor (TH1) which is a switching element.
By changing the variable resistance (VR) of (1), the AC voltage is phase-controlled to adjust the rotation speed of the motor (M).

The operation of the above circuit will be described below. First, when the power source is turned on and the AC voltage is supplied from the AC power source (1), it is full-wave rectified by the bridge circuit (B1) and applied to the phase adjustment circuit (2). At this point, the thyristor (TH1) is in the OFF state. The potential at point a in FIG. 4 (hereinafter referred to as the first potential (Va)) is
By four resistors (r1, R1, VR, R2), Vcc × (R1 + VR + R2) / (r1 + R1 + VR +
R2) (Vcc is a voltage generated by the bridge circuit), and the potential at point b (hereinafter, this is the second potential (Vb)
Will be Vcc × r2 / (r2 + r3).

As shown in FIG. 5, these first and second potentials (Va, Vb) fluctuate in a sinusoidal waveform having the same period as the AC voltage generated by the AC power supply (1). The phase of the first potential (Va) is the same as the phase of the AC voltage generated by the AC power supply (1), but since the capacitor (C1) is connected in parallel to the resistor (r3) at point b, this capacitor Due to (C1), the phase of the second potential (Vb) lags behind these waveforms.

The first and second potentials (V
a, Vb) is detected by the trigger circuit (3),
When the potential (Vb) of 2 exceeds the first potential (Va), the trigger current is supplied from the trigger circuit (3) to the thyristor (TH1), and the thyristor (TH1) is turned on. When the thyristor (TH1) is turned on, the AC voltage generated by the AC power supply (1) is supplied to the motor (M). The thyristor (TH1) keeps on until the AC voltage becomes 0V, so that the AC voltage becomes 0V from the time (t1) when the thyristor (TH1) turns on as shown in FIG.
AC voltage is applied to the motor (M) by the time (t2)
The electric power is supplied to the motor (M) by the amount corresponding to the area (S1) shown in FIG. 5, and the motor (M) rotates.

The operation of adjusting the rotation speed of the motor (M) by phase control in the above circuit will be described below. In this case, the variable resistor (V
The resistance value of R) may be changed. That is, when the variable resistance (VR) is changed, the first potential (Va) has the same period and phase as the AC voltage, but the amplitude thereof fluctuates as shown in FIG. The middle part of FIG. 5 shows the case where the resistance value of the variable resistance (VR) is maximum, and the lower part shows the case where it is minimum.

When the variable resistance (VR) is maximum, the first potential (Va) becomes small, so that the time (t1) at which the second potential (Vb) exceeds this becomes early, and the variable resistance (VR) is also increased.
Since the amplitude of the first electric potential (Va) becomes large when is smaller than the minimum value, the time point (t) at which the second electric potential (Vb) exceeds this value (t
1 ') is later than t1. Then, since the time until the thyristor (TH1) is turned on by the trigger circuit (3) can be adjusted in this way, when the VR is maximum, the thyristor (TH1) is turned off at t1 as shown in FIG.
A large amount of electric power corresponding to the area (S1) in FIG.
When the VR is minimum, the thyristor (TH1) is turned on at t2 to turn on the region (S
Since a small amount of electric power corresponding to 2) is supplied to the motor (M), the number of rotations becomes small.

As described above, the electric power supplied to the motor (M) can be adjusted by adjusting the resistance value of the variable resistor (VR) to adjust the rotation speed of the motor (M). By the way, in the drive control circuit as described above, it is necessary to provide a variable resistor (VR) for adjusting the rotation speed of the motor (M) outside the apparatus (in this case, the cleaner). At this time, a variable resistor (VR), which is a part of an electric circuit that is not insulated from the AC power source (1), is exposed outside the device, and there is a risk of electric shock if touched accidentally by a human body. Therefore, the resistance value of the resistors (R1, R2) is set to a high value to raise the impedance of the AC power source (1) and the variable resistor (VR) to prevent electric shock. ing.

[0009]

However, according to the drive control circuit of FIG. 4 in which the above-mentioned electric shock prevention measures are taken,
High resistance (r1, r2) for preventing electric shock is variable resistance (R2)
Is connected in series, the range in which the amplitude of the first potential (Va) can vary is narrowed. In the above circuit, since the time when the second potential (Vb) exceeds the first potential (Va) is used as it is as the timing for turning on the thyristor (TH1), the amplitude of the first potential (Va) can be changed. The narrow range narrows the adjustable range of the timing at which the thyristor (TH1) turns on.

The adjustable range of the rotational speed is determined by the adjustable range of the timing of turning on the thyristor. For example, the thyristor (TH1) is turned on from the rise of the AC voltage.
If possible, even more power can be supplied to the motor (M), so the rotation speed of the motor (M) can be maximized. However, in the conventional circuit, as a result, the thyristor is limited to the range as shown in FIG. Since it was not possible to adjust the time until (TH1) was turned on and the rotation speed of the motor (M) could not be adjusted over the entire range, the adjustment range of the rotation speed of the motor (2) was further increased. There was a request to expand.

[0011]

According to the drive control circuit of the present invention, as shown in FIG. 1, a rectifier circuit for rectifying an AC voltage and a switching element for supplying / not supplying the AC voltage to a load. And a first potential setting unit that includes a first potential setting unit that generates a first potential that fluctuates in the same phase as the AC voltage and that adjusts the amplitude of the first potential, and a phase that is different from the phase of the AC voltage. A second potential setting unit that generates a second potential that fluctuates in phase and two potentials in which the first and second potentials match are stored in advance, and the potential between the two points is divided into a plurality of stages. The switching element is turned on by the divided voltage
With a table to which the respective timings to be assigned are assigned, and the first and second potentials are constantly detected, and the first and second potentials when the first and second potentials actually match By having a control unit that determines the timing at which the switching element is turned on by collating with the divided voltage of the table and turns on the switching element at the timing, the range in which the phase can be controlled is prevented while preventing electric shock. The present invention provides a drive control circuit that can be expanded to widen the adjustment range of the rotation speed of a motor.

[0012]

[Operation] According to the drive control circuit of the present invention, as shown in FIG. 1, the first potential (Va) that can be adjusted by the adjusting means.
Due to fluctuations in the amplitude of the voltage, two points of the voltages having the same first and second potentials are stored in advance, and each of the divided voltages obtained by dividing the two points into a plurality of stages is preset to the O of the thyristor (TH1).
It has a table to which N timings are assigned, and the timings are determined by collating the table and the points where the first and second potentials actually detected by the control unit during operation match. .

As a result, the entire range in which the number of revolutions of the motor can be changed is assigned to the points at which the first and second potentials stored in advance are stored in two points, and the divided voltage divided into a plurality of stages between them is assigned. By collating the actual detected voltage, even if the adjustable range of the first potential (Va) is narrowed, the rotational speed can be adjusted over the entire range in which the rotational speed of the motor can change.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A drive control circuit according to an embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the drive control circuit according to the embodiment of the present invention includes an AC power supply (11), a rectifier circuit (15), a first potential setting section (12), and a second potential setting section. (13), a controller (14A) equipped with a table, and a trigger circuit (14B)
, A motor (16) and a thyristor (TH11), and a thyristor (TH11) as a switching element.
Is a circuit for controlling the number of rotations of the motor (12) which is a load and is used for a vacuum cleaner or the like by controlling the ON / OFF operation of (1) and controlling the phase of the AC voltage.

In the circuit, the AC power source (11) is
It is a circuit that generates an AC voltage. The rectifier circuit (15)
It is a circuit that full-wave rectifies an AC voltage. In the first potential setting unit (12), a resistor (r11) and an electric shock preventing resistor (R11, R12) connected in series and a variable resistor (VR) which is an example of an adjusting unit are provided to the output of the rectifier circuit (15). It is a circuit that is connected and that has the same phase as the AC voltage but changes so that only its amplitude changes, and that generates a first potential (Va) that is the potential at point a in FIG.

In order to prevent electric shock, the electric shock preventive resistor (R1) connected to the variable resistor (VR) that has been exposed to the outside of the apparatus.
1, R12) have high resistance, and it is considered that the impedance of the AC power supply (11) and the variable resistance (VR) is increased by this, and electric shock is prevented. In the second potential setting section (13), the resistor (r3) and the capacitor (C11) are connected in parallel, and this and the resistor (r12) are connected in series and connected to the output of the rectifier circuit (15), While the amplitude is fixed, the second potential (V
This is a circuit for generating b).

The control unit (14) is a controller (14A)
And a trigger circuit (14B), the controller (1
4A) is provided with a table (not shown), always detects the first potential (Va) and the second potential (Vb), and based on this detection result and the above-mentioned table, the trigger circuit (14).
This is a circuit for controlling the ON / OFF operation of B). A table is built in the controller (14A).

As shown in FIG. 2, the amplitude of the first electric potential (Va) changes due to the change of the resistance value of the variable resistor (VR), and with this change, the first electric potential (Va) and the second electric potential (Va) are changed. The corresponding voltage of Vb) varies. The maximum value (Vmax) and the minimum value (Vmin) of the voltage are stored in the table in advance, and the maximum value (Vmax) and the minimum value (Vmi) thereof are stored.
n) and the potential difference (Vmax-Vmin) are divided into nine (V1
~ V9), as shown in Table 1 below, each of them is assigned a timing (t0 to t9) for turning on the thyristor, and is stored in this table.

[0019]

[Table 1]

The trigger circuit (14B) is a circuit for supplying a trigger current to the thyristor (TH11) under the control of the controller (14A) to turn on the thyristor (TH11). The thyristor (TH11) is an example of a switching element that supplies an AC voltage to the motor (16) by performing an ON / OFF operation to rotate the motor (16).

The operation of the drive control circuit according to the embodiment of the present invention will be described below with reference to the drawings. First, when an AC voltage is applied from the AC power supply (11), it is full-wave rectified by the rectifier circuit (15) and supplied to the first and second potential setting sections (12, 13). At this point, the thyristor (TH11) is in the OFF state.

Then, as shown in FIG. 2, the first potential (V
a), the second potential (Vb) fluctuates. Since the first potential setting unit (12) does not include a capacitor, there is no phase delay, the first potential (Va) fluctuates in the same phase as the AC voltage, and the second potential setting unit (13) ) Includes a capacitor (C11), the phase fluctuates later than the AC voltage, and a waveform as shown in FIG. 2 is drawn.

The first and second potentials (Va, Vb) are constantly detected by the controller (14A),
The potential at which they match is also the controller (14
It is detected in A). At this time, the first detected
The potentials at which the second potentials (Va, Vb) match are collated with the division potentials stored in a table (not shown) in the controller (14A), whereby the thyristor (TH11).
The timing of turning on is determined, and the thyristor (TH11) is turned on according to the timing thus determined.

For example, the actually detected potential is Vma in Table 1.
If it corresponds to x, the corresponding t0 is selected as the ON timing, and the thyristor (TH11) is turned ON at this timing (t0). When the resistance value of the variable resistor (VR) is changed in the above circuit, the value shown in FIG.
As shown in, the amplitude of the first electric potential (Va) increases and decreases, and as the electric potential increases and decreases, the first electric potential (Va) and the second electric potential (Vb) increase.
The corresponding voltage of f also fluctuates. This voltage fluctuates between the maximum value (Vmax) and the minimum value (Vmin) of the voltage shown in FIG. 2, and as shown in Table 1, at this maximum value (Vmax), t0 shown in FIG. Since the time is assigned and the minimum value (Vmin) is assigned to t8 shown in FIG. 3, that is, the fall time of the AC voltage, the thyristor (TH11) is reached at t0 when the rotation speed of the motor (M) becomes maximum. Can be turned on.

Therefore, as shown in FIG. 5, the point at which the first and second potentials (Va, Vb) match is used as it is for the timing of turning on the thyristor, so that the number of revolutions of the motor becomes maximum. It becomes possible to expand the adjustable range of the rotation speed of the motor (M) as compared with the conventional case in which the thyristor cannot be turned on when the AC voltage rises (corresponding to t0 in FIG. 3). In this case, the electric shock prevention resistor (R1
1, R12) becomes a high resistance and the first potential (V
Even if the adjustable range of a) is narrowed, the adjustable range of the rotation speed of the motor (M) can be ensured to the maximum range by changing the setting of the table regardless of that.

Further, although a motor for a vacuum cleaner is used as an example of the load (12), the present invention is not limited to this, and for example, a motor used for a juicer, a mixer, a lathe, or a desk lamp. The same effect can be obtained even when used for brightness adjustment of a light bulb.

[0027]

According to the drive control circuit of the present invention, two points of the voltages having the same first and second potentials are stored in advance by the fluctuation of the amplitude of the first potential which can be adjusted by the adjusting means. However, there is a table in which the timing at which the thyristor is turned on is assigned in advance to each of the divided voltages obtained by dividing the interval between them, and the timing is based on this table and the first timing actually detected by the controller during operation. Since the points where the first and second electric potentials match are determined by collation, even if the adjustable range of the first electric potential is narrowed, the rotational speed can be changed over the entire range in which the rotational speed of the motor can change. Can be adjusted.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a drive control circuit according to an embodiment of the present invention.

FIG. 2 is a first graph illustrating the operation of the drive control circuit according to the embodiment of the present invention.

FIG. 3 is a second graph illustrating the operation of the drive control circuit according to the example of the present invention.

FIG. 4 is a circuit diagram of a drive control circuit according to a conventional example.

FIG. 5 is a graph illustrating an operation of a drive control circuit according to a conventional example.

[Explanation of symbols]

 (11) AC power supply (12) First potential setting unit (13) Second potential setting unit (14) Control unit (14A) Controller (14B) Trigger circuit (15) Rectifier circuit (16) Motor (load) ( TH11) Thyristor (switching element) (VR) Variable resistance

Claims (2)

[Claims] 1. A rectifier circuit for rectifying an AC voltage, a switching element for supplying / non-supplying the AC voltage to a load, and a first potential that fluctuates in phase with the AC voltage,
And a first potential setting unit that includes an adjusting unit that adjusts the amplitude of the first potential, and a second potential setting unit that generates a second potential that varies in a phase different from the phase of the AC voltage. A table in which two potentials at which the first and second potentials coincide with each other are stored in advance, and a timing at which the switching element is turned on is respectively assigned to a divided voltage obtained by dividing the potential between the two points in a plurality of stages It has, and always detects the first and second potentials, and compares the first and second potentials when the first and second potentials actually match with the divided voltage of the table. A drive control circuit for determining a timing at which the switching element is turned on by the controller and turning on the switching element at the timing. 2. A plurality of resistors and a variable resistor connected in series are connected to an output of the rectifier circuit in the first potential setting unit, and a resistor and a capacitor connected in parallel in the second potential setting unit. The drive control circuit according to claim 1, wherein a resistor connected in series to is connected to the output of the rectifier circuit, the switching element is a thyristor, and the adjusting unit is the variable resistor.