JPH079597Y2 - Electric volume drive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a drive device for an electric potentiometer, which is adapted to operate an electric potentiometer by driving a motor, which is used in various household electric appliances. is there.

<Prior Art> As shown in FIG. 2, a conventional electric potentiometer drive device of this type uses an ascending signal up or a descending signal down that is alternatively output from two output terminals of a comparator CP. The motor driving integrated circuit MD drives and controls the motor M so as to rotate it in the forward or reverse direction, and the rotation of the motor M operates an electric potentiometer (not shown) so that its resistance value increases or decreases. There is.

Further, the operating point of the electric volume is adapted to be set by the reference voltage V _REF to be input to the fourth input terminal P4 of the comparator CP, the reference voltage V _REF is by turning on the first switch S1 A first value for dividing the DC voltage Vcc by the resistors R ₀ and R ₁ and a second value for dividing the DC voltage Vcc by the resistors R ₀ and R ₂ by turning on the second switch S 2.
The value of and can be set selectively. In this example, a case where two types of reference voltages are set is shown for simplification of description, but in reality, a large number of sets of electronic switches and voltage dividing resistors are provided.

Further, the detection voltage to be compared with the set reference voltage V _REF is obtained by the detection volume VR which is operated in conjunction with the electric volume by the motor M while the DC voltage Vcc is applied. The detection voltage of the operating piece of the comparator is the second and third input terminals P of the comparator CP.
Input to P2. Then, when this detected voltage matches the set reference voltage V _REF , the signal u
The detection volume VR is operated by the motor M until neither p nor down is output.

Furthermore, in order to prevent the motor M and the volume VR from vibrating due to the mixing of electrical noise or the generation of vibration when the volume VR is operated to the set position by the reference voltage V _REF , the first of the comparator CP is provided. The input voltage to the input terminal P1 is set to an auxiliary reference voltage slightly smaller than the reference voltage V _REF by the two resistors R ₃ and R ₄ , and the first input terminal P1 and the fourth input terminal Electric noise is absorbed by the potential difference. For example, the voltage V between the first input terminal P1 and the fourth input terminal P4 when the first switch S1 is on.
_1-4 are the resistance values of the resistors R ₀ , R ₁ , R ₃ , and R ₄ , respectively r ₀ and r
_{If 1} , r ₃ , r ₄ , Therefore, the integrated circuit MD for driving the motor drives the motor based on the output of the comparator CP so that the detection voltage of the detection volume VR input to the input terminals P2 and P3 of the comparator CP falls within the range of the voltage V _1-4. M is drive-controlled, and the detection volume VR and the electric volume are finally rotated to a position determined by the reference voltage V _REF .

<Problems to be solved by the invention> However, when the resistance value of the electric potentiometer is set to the minimum value or in the vicinity of the minimum value, that is, when the reference voltage V _REF is set to almost 0 V, the second switch S2 is now set. If the resistance value of the resistor R ₂ is r ₂ and it is for setting the minimum value, this resistance value
Since r ₀ is for setting the minimum value, r ₀ >> r ₂ and the voltage _1-4 between the first input terminal P1 and the fourth input terminal P4 of the comparator CP at this time is Becomes Here, since R ₀ >> R ₂ as described above, R ₂ /
(R ₀ + R ₂ ) ≈0.

That is, since the reference voltage V _REF is stepped down by the two resistors R ₃ and R ₄ to generate the auxiliary reference voltage, the above-mentioned first input terminal P1 is proportional to the reduction of the reference voltage V _REF. When the fourth input terminal will become a voltage _1-4 small between P4, since much smaller than the (2) voltage V _1-4 is (1) the voltage V _1-4 of the electrical When disturbance such as static noise or vibration is applied, the second volume of the comparator circuit CP is detected from the detection volume VR.
And the detection voltage applied to the third input terminals P2 and P3 has decreased, and the voltage between the first input terminal P1 and the fourth input terminal P4 has decreased.
It is easy to go out of the range of V _1-4 , and when it goes out, a signal that tries to keep the detection voltage within the range of voltage V _1-4 is output.
VR and electric volume will vibrate.

The present invention has been made in view of the above-mentioned conventional problems, and provides an electric volume drive device in which vibration does not occur even when the resistance value of the electric volume is set to a minimum value or in the vicinity of the minimum value. Is a technical issue.

<Means for Solving the Problems> According to the present invention, an electric volume drive device is configured as follows as a technical means for achieving the above-mentioned problems. That is, a reference voltage for setting the operating position of the electric potentiometer is set by selectively turning on a plurality of setting switches and inserting and connecting individual voltage dividing resistors by the respective switches. An auxiliary reference voltage for preventing malfunction that has a slight potential difference with respect to the reference voltage is input to each individual input terminal of the comparator, and the detection voltage from the detection volume that is operated by the motor in conjunction with the electric volume In the electric volume drive device for comparing the reference voltage and the auxiliary reference voltage in the comparator, and controlling the drive of the motor so that the detected voltage is within the range between the reference voltage and the auxiliary reference voltage, Of the auxiliary reference voltage of each of the switches and the comparator for setting the minimum value of the electric potentiometer and a value close to the minimum value. Between the power terminals are configured as characterized in that a resistor to be inserted and connected by turning on the corresponding said switch respectively.

<Operation> When the resistance value of the electric potentiometer is set to the minimum value or in the vicinity of the minimum value by turning on the corresponding switch, the switch in the ON state is used to set the auxiliary voltage setting resistance in addition to the reference voltage setting resistance. A resistor is connected to the auxiliary reference voltage input terminal of the comparator. With this auxiliary voltage setting resistor, it is possible to obtain an auxiliary reference voltage that is a comparatively large step-down of the small reference voltage that sets the resistance value of the electric potentiometer to the minimum value. The potential difference of does not decrease in proportion to the decrease of the reference voltage as in the conventional case, and the volume does not vibrate due to the mixing of electrical noise or the occurrence of vibration.

<Embodiment> Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is an electric circuit diagram of an embodiment of the present invention. In FIG. 1, the same or equivalent parts as those in FIG. 2 are designated by the same reference numerals and the description thereof will be omitted. The difference from FIG. 2 is that instead of the resistor R ₃ , a resistor R ′ having a different resistance value is used.
₃ is connected, and the resistor R ₅ is connected between one end of the second switch S2 for setting the minimum value of the resistance value of the electric potentiometer and the first input terminal P1 of the comparator CP. As the resistor R ₅ , a resistor whose resistance value r ₅ has a relation of r ₅ << r ₄ is selected.

Next, the operation of the above embodiment will be described. When only the second switch S2 is turned on and the minimum value of the electric potentiometer is set, the voltage V _1-4 between the first input terminal P1 and the fourth input terminal P4 of the comparator CP at that time is R _{Since 5} ≪ R ₄ , And the resistance value r ₅ is not too large for the resistance value r ₃ ,
The value in the parentheses is larger than the value in the parentheses in the equation (2). Therefore, the voltage V _1-4 is also a sufficiently large value, and the volume does not vibrate due to electrical noise or the like. Note that since the second switch S2 is in Figure 2 and the same conditions at the time of OFF, if _{r 3 = r '3 (r} 2 + r 5) and so as the resistance R' _3, selected R ₅ Good.

For example, it may be the _{r '3 = r 5 = 1} / 2r 3 »r 2.

<Effects of the Invention> The present invention has the following effects because it is configured and operates as described above. That is, when the resistance value of the electric potentiometer is set to the minimum value or in the vicinity of the minimum value, the auxiliary reference voltage setting resistor is connected by the setting switch to set the auxiliary reference voltage smaller than the conventional value, Since the potential difference between the voltage and the auxiliary reference voltage can be increased, the electric potentiometer can be stopped without vibrating to the set position even when electric noise is mixed or vibration is generated.

[Brief description of drawings]

FIG. 1 is an electric circuit diagram of an embodiment of the present invention, and FIG. 2 is an electric circuit diagram of a conventional device. _{R 0, R 1, R 2} ... reference voltage setting resistor _{R '3, R 4, R} 5 ... auxiliary reference voltage setting resistor S1, S2 ...... setting switch M ...... motor CP ...... comparator P1 ...... auxiliary Reference voltage input terminals P2, P3 …… Detection voltage input terminal P4 …… Reference voltage input terminal VR …… Detection volume

Claims (1)

[Scope of utility model registration request] 1. A reference voltage for setting an operating position of an electric potentiometer is set by selectively turning on a plurality of setting switches and connecting an individual voltage dividing resistor by each switch. The reference voltage and the auxiliary reference voltage for preventing malfunctions that has a slight potential difference with respect to the reference voltage are input to the individual input terminals of the comparator, respectively, and the detection volume is operated by the motor in conjunction with the electric volume. While comparing the detected voltage of the with the reference voltage and the auxiliary reference voltage in the comparator,
In the electric potentiometer drive device for controlling the drive of the motor so that the detected voltage falls within the range between the reference voltage and the auxiliary reference voltage, each of the minimum value of the electric potentiometer and a value close to the minimum value is set. An electric volume drive device is provided with a resistor provided between the switch and an input terminal of the auxiliary reference voltage of the comparator so as to be interleaved by turning on the corresponding switch.