JPH0574924B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to potentiometers, particularly continuously rotating potentiometers.

B. Summary of the Invention The present invention provides a resistor having a circular shape with a part cut out, a contactor rotatably disposed at the center of the resistor, and a contactor on the resistor. In a potentiometer that slides one end and obtains a rotation angle based on the resistance value between the other end of the contact and one end of the resistor, a part of the resistor formed in a circular shape is cut out and The first part is arranged such that the notch positions of the parts are different from each other.
and a second resistor, and first and second resistors each of which is rotatably disposed at the center of the first and second resistors and slides on the first and second resistors, respectively. a third resistor connected between one end of the first resistor and one end of the second resistor, and a third resistor connected between the other end of the first resistor and the second resistor. and a fourth resistor connected between the other end of the contactor, and by collectively connecting one end of the first and second contactors, a simple configuration can be achieved without using an external device. This is intended to improve the reliability of rotation angle detection by eliminating the rotation angle detection indeterminate area caused by the notch of the resistor.

C. Prior Art A rotary potentiometer is a variable resistor whose rotation angle is proportional to the output resistance value, and is used in combination with a dial knob (volume) of an operating device, detection of the rotation angle of a motor, and a rack and pinion gear. It is widely used for linear position detection. Among these, continuous rotation type potentiometers are ones in which the potentiometer itself mechanically rotates continuously, and can easily follow continuous rotation even when used in conjunction with equipment that may rotate continuously, such as a motor. . In the case of general rotary potentiometers other than the continuous rotary type, there is a mechanical stop position within the potentiometer itself, and if an external device such as a motor tries to force it to rotate, it may stop in some cases. Continuously rotating potentiometers are used in such places because there is a risk of potentiometers being destroyed.

Here, FIG. 7 shows an example of a general continuous rotation type potentiometer. In FIG. 7, reference numeral 1 denotes a resistor that is formed in a circular shape, has a gap in part, and has a uniform resistance value. This resistor 1
Both ends are connected to terminals a and c, respectively. 2 is a contact disposed at the center of the resistor 1 so as to be continuously rotatable. One end of this contactor 2 slides on the resistor 1, and the other end is connected to terminal b. In the potentiometer configured in this way, the resistance value between the end of the resistor 1 and the contact point between the contact 2 and the resistor 1 changes according to the rotation of the contact 2. Therefore, the rotation angle can be detected by applying a reference voltage between terminals a and c and detecting the potential difference between terminals a and b, for example.

D. Problems to be Solved by the Invention In the potentiometer configured as described above, the resistor 1 cannot be arranged continuously on the circumference in principle, and as shown between both ends of the resistor 1 There is a small portion without a resistor. For this reason, although the contactor 2 rotates mechanically continuously, it becomes electrically discontinuous. That is, when the contactor 2 comes to a part where there is no resistor, for example, the terminals a and b are in an open state and the resistance value becomes infinite. Therefore, when the contactor 2 comes to a part where there is no resistor, the potential difference between terminals a and b becomes unstable. Therefore, in a system that performs control based on the output of a potentiometer, problems such as an uncontrollable situation occur.

Therefore, potentiometers were generally used in the following way.

(1) A method of using a potentiometer by sliding the contact only within a certain range of the resistor.

(2) A method in which two similar potentiometers are provided and used in conjunction with each other, and the discontinuous area of one is covered by the other.

Among these methods, the method described in item (1) above has disadvantages in that it cannot take advantage of mechanically continuous rotation, and that there is also a risk of creating a discontinuous region. Furthermore, in the method described in item (2) above, for example, one potentiometer is used as the main component, and the means for recognizing that the potentiometer is in the discontinuous region and the means for switching the output to the other potentiometer are two potentiometers. There are aspects other than the yometer that are required, and this is disadvantageous considering that the reliability of the potentiometer may deteriorate. Furthermore, if these functions are performed by a higher-level device such as a computer, a mechanism for that purpose is not required, but a separate means for transmitting the outputs of the two potentiometers is required, which causes problems such as an increase in the number of cables. There's a problem.

The present invention has been made in view of the above points, and provides a potentiometer that eliminates the rotation angle detection indeterminate area with a simple configuration without using an external device, and improves the reliability of rotation angle detection. The purpose is to

E Means for Solving Problems The present invention provides first and second resistors, which are formed by cutting out a part of a circularly formed resistor and disposed so that the notch positions are different from each other. first and second contacts that are respectively disposed at central positions of the first and second resistors so as to be rotatable in conjunction with each other and slide on the first and second resistors, respectively; a third resistor connected between one end of the resistor and one end of the second resistor; and a third resistor connected between the other end of the first resistor and the other end of the second resistor. and a fourth resistor, and one ends of the first and second contacts are connected together.

F Effect In the potentiometer configured as described above, the positions of the notches of the first and second resistors are different from each other, and the first and second resistors are connected to the third and fourth resistors. Since they are connected in this manner, there is no rotation angle detection unstable area, and an output proportional to the angle can be obtained in the entire range of 0° to 360°.

G. Embodiment Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In FIG. 1, reference numeral 10 denotes a first resistor that is formed in a circular shape, has a gap in part, and has a uniform resistance value. A second resistor 20 is formed in a circular shape and has a uniform resistance value, and a gap is provided at a position different from that of the first resistor 10 . First resistor 1
A contact 5a that slides on the resistor 10 is disposed at the center position of the resistor 10 so as to be continuously rotatable. At the center of the second resistor 20, a contact 5b that slides on the resistor 20 in conjunction with the contact 5a is disposed so as to be continuously rotatable. Second resistor 20
One end of the resistor is connected to the terminal c', and also connected to one end of the first resistor 10 via the third resistor 3. The other end of the first resistor 10 is connected to the terminal a', and the second end is connected to the terminal a' via the fourth resistor 4.
is connected to the other end of the resistor 20. One ends of the contacts 5a and 5b are collectively connected to a terminal b'. In the potentiometer configured as described above, the contacts 5a and 5b rotate continuously in conjunction with each other, and when the reference voltage E is applied between the terminals a' and c', The rotation angle θ can be recognized by the potential difference V between. The potentiometer shown in FIG. 1 has the position of the gap formed by both ends of the resistor 10 (position where the resistor 10 does not exist) and the position of the gap formed by both ends of the resistor 20 (position where the resistor 20 does not exist). ) are arranged differently, so both contacts 5a and 5b are connected to the resistor 1.
A state in which it does not touch 0 or 20 (undefined region) can be avoided. Therefore, the operating state of the potentiometer shown in FIG. 1 is as follows.

() Contacts 5a and 5b are resistors 10 and 20, respectively.
(both are not indeterminate regions).

() The contactor 5a is located at a gap position (undefined area) between the resistor 10, but the contactor 5b is in contact with the resistor 20.

() The contactor 5b is located at a gap position (undefined area) between the resistor 20, but the contactor 5a is in contact with the resistor 10.

Next, the operation of each state of the above-mentioned (), (), and () terms will be explained with reference to the equivalent circuit diagrams of FIGS. 2 to 6.

First, the equivalent circuit of the potentiometer shown in FIG. 1 in the state described in () above is shown as shown in FIG. 2. In FIG. 2, R11 is the terminal of the resistor 10.
The resistance value from the end on the a' side to the contact between the contact 5a and the resistor 10, R12 is the resistance value from the contact between the contact 5a and the resistor 10 to the end of the resistor 10 on the resistor 3 side, R3 is the resistance value of resistor 3, R4 is the resistance value of resistor 4
R21 is the resistance value from the end of the resistor 20 on the resistor 4 side to the contact between the contact 5b and the resistor 20, and R22 is the resistance from the contact between the contact 5b and the resistor 20 to the terminal of the resistor 20. The resistance values on the c′ side and up to the end are shown respectively. FIG. 2 can be represented by the equivalent circuit of FIG. Each resistance value in FIG. 3 is expressed by the following equation.

RA=R11, RB=R3+R12, RC=R4+R21, RD=R22, ...(1) The reference voltage E is applied between terminals a' and c' of the circuit shown in Figure 3.
The equivalent circuit when . At this time, the resistance values RA, RB, RC, RD and _R
There is a relationship between R _Y as shown in the following equation.

1/R _X =1/RA+1/RC, 1/R _Y =1/RB+1/RD}
...(2) Also, the potential difference V between terminals a' and b' in FIG. 4 is expressed by the following equation.

_{V =} E× _R RA+RC)/RA×RC×(RB+
RD)=E×1/1+(R3+R12)×R22×(R11+R4+R21
)/(R4+R21)×R11(R22+R3+R12)...(4). Here, for example, the undefined areas (resistors 10, 20) of two potentiometers (resistors 10, 20)
20 gap) is set to 60° (that is, the effective area is
300°), two potentiometers (resistor 10,
20) are mechanically connected with a 60° shift. Then, when the resistance value of the resistor 10 is R1 and the resistance value of the resistor 20 is R2, the resistance values R11,
The function of R21 and angle θ can be expressed as R11=R1×θ/300°, R21=R2×θ−60°/300° (5). Furthermore, R3=R4=r ₁ , R1
= R2=r ₀ , R11=r ₀ ×θ/300° R12=r ₀ × (1−θ/300°) R21=r ₀ ×θ−60°/300° R22=r ₀ × (−θ−60°/300°) R3=R4=r ₁ ...(6) It can be expressed as follows.

Here, if θ/300°=F, r ₀ = 5×r ₁ , equation (4) becomes V=E×1/1+(r ₁ +r ₀ (1-F)(r ₀ (1-F )+
r ₁ ) (r ₀ F+r ₁ +r ₀ F−r ₁ )/r ₀ F−(r ₁ +r ₀ F−r ₁ )(r ₁
+r ₀ (1-F) + r ₀ (1-F) + r ₁ ) =E×1/1+r ₁ +r ₀ (1-F)/r ₀ F=E×r ₀ F/r ₀ F
+r ₁ +r ₀ (1-F)=E×5/6F=E×5/6×θ/
It can be expanded as 300°...(7). From this equation (7), in the state of the above () (the state in which the contacts 5a and 5b are in contact with the resistors 10 and 20, respectively), by selecting each parameter, the output potential difference V is proportional to the rotation angle θ. It can be seen that the following can be obtained.

Next, in the state of item () above (the contact 5a is in the gap position (undefined area) of the resistor 10,
An equivalent circuit of the potentiometer shown in FIG. 1 in a state where b is in contact with the resistor 20 is shown as shown in FIG. Since the output potential difference V between terminals a' and b' in this state is V=E×R4+R21/R4+R2, this equation can be used in equation (1) to
By substituting equation (6) and θ/300°=F, r ₀ = 5×r ₁ , V=E×r ₁ +rF ₀ −r ₁ /r ₁ +r ₀ =E×5/6×θ/3
00°...(8), and the same result as the equation (7) described in the state description in section () above can be obtained. That is, from equation (8), it can be seen that in the state of the above-mentioned (), an output potential difference V proportional to the rotation angle θ is obtained.

Next, in the state of item () (the contact 5b is in the gap position (undefined area) between the resistors 20,
The equivalent circuit of the potentiometer shown in FIG. 1 is shown in FIG. 6 (a is in contact with the resistor 10). Since the output potential difference V between terminals a' and b' in this state is V=E×R11/R1+R3, we can use equations (1) to (6) and θ /300°=F, by substituting r ₀ = 5 x r ₁ , V=E x r ₀ F/r ₀ + r ₁ = E x 5/6 x θ/300°...
(9), and the same result as Equation (7) described in the state explanation in section () above can be obtained. That is, from equation (9), it can be seen that in the state of the above-mentioned (), an output potential difference V proportional to the rotation angle θ is obtained.

As is clear from the above explanation, the resistors 10 and 2
No matter what state the contacts 5a and 5b are in, an output potential difference proportional to the rotation angle θ can be obtained over the entire range from 0° to 360°. In addition, as in the above embodiment, the undefined area (gap part) of the resistors 10 and 20 is
60°, effective area (area where resistor exists) 300°
, the ratio is 60°/300° to R3(R4)/R1(R2
) can be reduced to 1/5. That is, for example, R1=
Set R2 = 5KΩ, R3 = R4 = 1KΩ.

H Effects of the Invention As described above, according to the present invention, the following effects can be obtained.

(1) Although there was an electrically undefined region in the output of a conventional potentiometer, there is no undefined region in the output of the potentiometer of the present invention. Therefore, a specific output value is always obtained.

(2) Since a specific output value is always obtained, the reliability of the system is significantly improved when control is performed based on the output of the bontensiometer.

(3) In the conventional method, an external stopper was added to eliminate the undefined area, but with the potentiometer of the present invention, such a method is no longer necessary. Therefore, the device configuration becomes extremely simple.

(4) An output proportional to the rotation angle can be obtained in the entire range from 0° to 860° without using an external device for recognizing the undefined region, which was conventionally used.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing one embodiment of the present invention, and FIG.
6 to 6 are equivalent circuit diagrams for explaining the embodiment, and FIG. 7 is a configuration diagram showing an example of a conventional potentiometer. 3...Third resistor, 4...Fourth resistor, 1
0...First resistor, 20...Second resistor, 5
a, 5b... Contact.

Claims (1)

[Claims] 1. First and second resistors which are formed by cutting out a part of a circularly formed low antibody and are arranged so that the positions of the notches are different from each other;
first and second contacts, which are each arranged rotatably at the center of the resistor and slide on the first and second resistors, respectively; one end of the first resistor; a third resistor connected between one end of the second resistor and a fourth resistor connected between the other end of the first resistor and the other end of the second resistor; 1. A potentiometer comprising: a body, and one ends of the first and second contacts are connected together.