JPS59222767A - Rotary direction detecting apparatus of rotary switch - Google Patents

Abstract

PURPOSE:To certainly detect the rotary direction of a movable change-over point, by a method wherein fixed contacts are divided into groups which are, in turn, connected to lead wires while converting digital signals outputted from said lead wires to a binary count value. CONSTITUTION:A rotary switch RS has fixed contacts a-l and a movable change-over contact (m). The fixed contact a-l are divided into three groups which are, in turn, respectively connected to lead wires A-C. Digital position signals showing the change-over position of the movable change-over contact (m) are outputted from the lead wires A-C. A control circuit D judges the rotary direction of the movable change-over contact (m) on the basis of said digital position signals and controls a digital display device E and a D/A converter F with regard to the rotary direction thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotation direction detection device for a rotary switch.

When a movable switching contact is rotatable endlessly with respect to multiple fixed contacts and used in a so-called endless state, it is necessary to detect the direction of rotation of the movable switching contact and cause the display contents to count up or down. be.

For this reason, conventionally, the structure of the switch itself has been changed to mechanically or optically detect the rotation direction of the movable switching contact, but this tends to result in a complicated structure and poor assembly workability. This is not desirable due to various aspects such as increased cost due to an increase in the number of parts.

Therefore, an object of the present invention is to provide a rotary switch rotation direction detection device that can reliably detect the rotation direction of a movable switching contact without modifying a commercially available rotary switch.

Hereinafter, the present invention will be described in detail with reference to an embodiment shown in the accompanying drawings.

FIG. 1 shows an embodiment in which the present invention is applied to a rotary switch R8 having, for example, 12 fixed contacts. That is, this rotary switch R3 has 12 fixed contacts a to Q arranged on the same circumference,
It is provided with an endlessly rotatable movable switching contact m that selectively switches each of these fixed contacts a7Q without short-circuiting.

In this embodiment, the above 12 fixed contacts a''
Q has four groups, for example (a, b, c), (d, e, 4), with three adjacent ones forming one group.

Cgz h+ ')r (J+ ky Q), and three lead wires A for each group.

B and C are available. That is, to the lead wire A, the first fixed contacts a+d+gyj of each group are connected as seen clockwise in FIG. 1, and to the lead wire B, the second fixed contacts of each group are connected. Each fixed contact of
e, h, k are connected, and for lead wire C,
The third fixed contacts c, f, t, and Ω of each group are connected, respectively. In this way, each fixed contact a~Q
By connecting the lead wires A, B, and C, three digital position signals (100,010,001) indicating the switching position of the movable switching contact m are output from the lead wires A, B, and C. It turns out. And this detection device is
A control circuit is provided which determines the rotational direction of the movable switching contact m based on the digital position signal and controls, for example, a digital display E and a D/A converter F in relation to the rotational direction. In this case, the control circuit actually consists of a microcomputer, and as illustrated in FIG. A binary code conversion means G for converting a digital position signal into a binary value, a rewritable storage means H for storing a binary count value outputted from the binary code conversion means G, and a movable switching contact m. The binary count value Y of the binary code conversion means G that is changed by the switching operation, and the storage means H as the position signal before the switching operation.
In response to the binary count value X stored in .

Y=X+1...(1) or Y=X-2...
- If either of the equations (2) holds true, it is determined that the movable switching contact m has been rotated in the clockwise direction in FIG. 1, that is, in the increasing direction in this embodiment;

If neither of (2) holds true, it is determined that the rotation has been made in the counterclockwise direction, that is, in the decreasing direction, and the binary count value Y is stored in the storage means 11 in place of the binary count value X. and an up/down count that counts up or down based on the discrimination output of the discrimination means I.

Next, the construction of the present invention will be explained with reference to the flowchart shown in FIG. In addition, reference numeral 8 in the same figure
1 to S indicate each step of this flowchart.

In step S1, when the start switch is turned on, the microcomputer D sends the indicators E and D/A
The initial value Z is output to the converter F (step S2). Note that this initial value Z may be a binary signal or a "0" display signal stored at the end of the previous operation. Then, in the next step S3, the digital signals from each lead wire A, B, and C are input to the binary code conversion means G,
The digital signal is converted into a binary signal (step S4). In this embodiment, the digital signal is converted to a binary signal of first order.

That is, when the movable switching contact m is at the position of the fixed contacts a and d1g+J, the value is 1, when the movable switching contact m is at the position of the fixed contacts bleTh, the value is 2, and the fixed contacts c and f.

When it is at position i, Q, the value is 3. Therefore, if this value changes from 1 → 2 → 3 → 1 →..., the movable switching contact m has rotated clockwise in Figure 1. On the other hand, if the numerical value changes as 1→3→2→1→..., it means that the rotation has been counterclockwise.

In this step S4, any one of the above numerical values is stored in the storage means H as a binary count value X. Next, in step S5, the digital signals of the lead wires A, B, and C are again read into the binary code conversion means G, and the binary count value Y is outputted in the next step S6. Then, in step S7, it is determined whether Y=X, and if Y=X, it means that the movable switching contact m has not been switched, and the process returns to step S5.

On the other hand, if Yf-X, the process moves to step S8 and Yf-X.
=O is determined. This is because the contact of rotary switch R3 is non-shorting, so the movable switching contact m
This step is to prevent malfunctions caused by "0" being always read when switching. In this step S8, if Y=O, the process returns to step S5, and if Y≠0, the process moves to step S9. In step S9,
Y-X+1...Equation (1) is determined, and if this equation (1) is established, step S11 is executed. That is, the amplifier count command signal is outputted from the determining means (2) to the up/down counter K, and the count value Q of the up/down counter becomes X+1. In this embodiment, the above count value Q and a predetermined maximum value M a x
A step S12 is prepared to compare Q<M.
ax, the process moves to step S13, and this count value Q
(=Z+1) is replaced as a new initial value Z, and this numerical value Z is output to the display E and the D/A converter F (step 514). Then, in step S15, the binary count value Y is read into the storage means H and replaced with the previously stored count value X, and the process returns to step S5 to wait for the next input. In step S12, if Q>Max, steps S13 and S14 are skipped and the process proceeds to step S15.

If equation (1) does not hold in step S9, it is further determined in step SIO whether Y=X-2...equation (2). When this formula (2) holds, the movable switching contact m becomes 3→1, that is, the fixed contacts C→d, f→g,
1-)j or Q-+a, the process moves to step S11. Step S]
If the above formula (2) does not hold for O, step S1
6 is executed. That is, a down-count command signal is issued from the discriminator to the up-down counter K, and the count value Q of the up-down counter becomes Z-1.

Then, in step S17, this count value Q is compared with a predetermined minimum value Min, and Q > M
If it is in, the process moves to step 313, and on the other hand, Q
If <M in, step S1.3. Skipping S14, the process moves to step S15.

In the above embodiment, three lead wires A, B, and C are connected to the rotary switch R3 having 12 fixed contacts. The lead wires may be divided into groups and the number of lead wires may be four correspondingly. That is, in this invention, since the switching direction is determined using three fixed contacts as the minimum unit, N fixed contacts (N is 3 or more) are used as one
In the case of grouping, N lead wires may be used, and the general formula of equation (2) of step SIO above is Y=X-(
N-1). Furthermore, if the maximum value and minimum value are not required, steps S12 and S17 may be omitted. On the other hand, when using multiple digits by arranging rotary switches for each digit, step S
], l as QdZ+n, step S16 as Q=Z
-n) (where n=:10X, x is the number of digits). Furthermore, when converting the digital signals appearing on the square lines A, B, and C into binary reduction values by the binary code conversion means G, the order of the counted values is changed and the above equations (1) and (2 ) may be determined to be a decrease direction switch, and if neither of these conditions is true, an increase direction switch may be determined. Note that if the rotary switch R8 has a shortig structure, the lead wires A, B
, C, signals such as 011 are input at the same time, so they cannot be used.

As is clear from the description of the embodiments described above, according to the present invention, the rotation direction of a rotary switch can reliably detect the rotation direction of a movable switching contact without changing the structure of a commercially available rotary switch. Equipment is provided.

[Brief explanation of the drawing]

FIG. 1 is a schematic block diagram showing an embodiment of the present invention, FIG. 2 is a schematic functional block diagram of the microcomputer shown in FIG. 1, and FIG. 3 is a detailed diagram of the invention. This is a flowchart for explaining. In the figure, A, B, and C are Riet wires, R3 is a rotary switch, D is a microcomputer, E is a display, F is a D/H converter, G is a conversion means to pinary code 1, H is a storage means, is a discrimination means, and K is an up/down counter. Patent applicant Hioki Electric Co., Ltd. Representative Patent attorney Takuya Ohara Figure 3

Claims (1)

[Scope of Claim] A rotary switch having a non-shorting contact structure including three or more M fixed contacts and a movable switching contact that can be rotated endlessly to selectively switch each of the fixed contacts. The device detects the rotational direction of the movable switching contact, wherein the M fixed contacts are divided into groups of N (an integer of 3 or more) each, and the N fixed contacts are connected in common to each group. a lead wire, a binary code conversion means for converting a digitally converted position signal of the movable switching contact output via the lead wire into a binary count value, and a memory for storing the binary count value. means, X the binary division value stored in the storage means as the initial position of the movable switching contact; The numbers are Y and Y=X
+ ] ・ ・ ・ (1) or Y=X-(N-1) ... (2) It is determined whether the formula holds true or not, and the binary count value Y is stored as X in the storage means. Up-counting or down-counting depending on the determination means for replacing and storing, and the case where either of the above formulas (1) and (2) holds true, and the case where neither of the formulas (1,) and (2) hold true. A rotation direction detection device for a rotary switch, comprising a counting means for detecting the rotation direction of a rotary switch.