JP2639406B2 - Frequency measurement device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a frequency measuring device that measures a frequency corresponding to, for example, a rotational speed and enables output or display of the output in various different unit systems.

[Summary of the Invention]

The present invention sets numerical information related to an input frequency value and information of an output value having a functional relationship with the numerical value information,
The input / output ratio is automatically calculated, and output or display is performed while maintaining the input information and the specified functional relationship. When the output and display in multiple different unit systems are possible, It is easy to set, and even when the input / output ratio becomes a small number, an almost accurate ratio can be easily obtained.

[Conventional technology]

For example, when detecting the rotation speed of a rotating body, it is performed by measuring the frequency of a pulse from a pulse generator provided in association with the rotating body.

In this case, as the rotation speed output or its display value, in addition to the detection frequency itself, there are many cases where it is desired to output a value converted to a unit of [rpm] or a value obtained by multiplying the input by a predetermined ratio. As a frequency measuring device,
A device that can set the input / output ratio is conventionally known.

In the conventional apparatus, the way of setting the input / output ratio is to set the ratio itself. For example, input: output =
If you want to set 22: 7, you set 22/7 = 3.14 ...

[Problems to be solved by the invention]

However, such a method of directly inputting the input / output ratio requires a setter to calculate the input / output ratio at the time of setting before performing the setting operation, which is troublesome. An operation error sometimes occurred. Also,
When the setting ratio is a decimal number and cannot be divided, it is necessary to round down the value to an appropriate number of significant digits and input the value.

[Means for solving the problem]

In the present invention, input information setting means for setting numerical information related to the input frequency value, output information setting means for setting information of an electrical output value or output display numerical value having a functional relationship with the input frequency value, Means for calculating the input / output ratio from the set numerical information, and an electrical output or display output is obtained based on the calculation result while maintaining the input frequency information and the specified functional relationship.

[Action]

For example, when input: output = 22: 7 is set, “22” is set by the input information setting means, and “7” is set by the output information setting means. Then, 22/7 is obtained by the arithmetic means, and this is multiplied by the input frequency information to derive an electrical output and a display output.

It is sufficient to set the input information and the output information themselves, and there is no need for the setter to calculate the ratio, so that the input operation is easy and the accuracy is good.

〔Example〕

FIG. 1 is a block diagram of an example of the apparatus of the present invention. In the figure, (1L) and (1R) are input setting switches. In addition, (2) is a display unit composed of a liquid crystal display or the like, and in this example, as shown in FIG.

(3) is a display control circuit for supplying a display control signal to the display section (2).

In this case, the switch (1L) is used to switch the mode and the set digit, and as shown in FIG.
When the switch (1L) is a relatively long time on (hereinafter referred to as long-one), which is detected by the timer circuit (4), the detection signal L ₁ is obtained from the timer circuit (4), This is supplied to the mode setting circuit (5). The mode setting circuit (5) outputs the detection signal L ₁
Each time is input, a mode signal MODE for sequentially and cyclically changing the mode is obtained, and the mode signal MODE is supplied to the display control circuit (3).
The mode is switched according to.

The signal MODE is also supplied to a numerical value and decimal point position setting circuit (7) described later.

When the switch (1L) is turned on for a relatively short time as shown in FIG. 3B (hereinafter abbreviated as "short on"), and when this is detected by the timer circuit (4), the detection signal S ₁ is obtained from this, the signal S ₁ is supplied to the set of digits switching circuit (6). This set digit switching circuit (6)
Each time the detection signal S ₁ is input, obtain the digits switching signal for sequentially changing the digit 5 digits. The digit switching signal is supplied to the display control circuit (3) and to the numerical value and decimal point position setting circuit (7). The setting circuit (7) has a register for storing a numerical value for five digits and a decimal point position, and the digit setting signal and the position of the decimal point in this register are designated by a digit switching signal.

The switch (1R) is used to change the value and the decimal point position. When the switch (1R) is turned on for a long time as shown in FIG. 3A, it is detected by the timer circuit (8). than this switching signal L ₂ corresponding to the length on-time is supplied to the numerical and point setting circuit (7), in the setting circuit (7), is set by the digit switching signal from the setting digit switching means (6) During the ON time of the switch (1R), the numerical value of the digit is sequentially and continuously changed from “0” to “9”. Alternatively, the position of the decimal point is sequentially and cyclically changed from the highest digit to the lowest digit.

Also, when the switch (1R) is short on as in the third Figure B, which is detected by the timer circuit (8), this one shot of the pulsed switching signal S ₂ is obtained from this numerical and It is supplied to a decimal point position setting circuit (7), and the numerical value of the set digit is changed by 1 or the decimal point position is 1
It is shifted only one.

The numerical value and decimal point position information set in the register of the setting circuit (7) are supplied to the display control circuit (3). Also,
The setting circuit (7) is interconnected with the internal backup memory (9), and the set input value and output display value are stored in this memory (9).

For example, when the input frequency value is 1.2345Hz, the output display value
When it is desired to display 3741.7 Hz, 1.2345 is set and stored in the input value storage section (9I) of the memory (9), and 3741.7 is set and stored in the output display value storage section (9D). When the input value and the output display value are set, these values are read from the storage units (9I) and (9D) of the memory (9), and the ratio calculation circuit (10) calculates the ratio between the two. . The determined ratio value is stored in the register (11). The value of the ratio stored in this register (11) is
2) supplied to.

On the other hand, an input frequency signal from the input terminal (13) is supplied to a frequency measurement circuit (14), and the frequency is obtained.
The obtained frequency information is supplied to the display operation circuit (12), multiplied by the value of the ratio from the register (11), and changed to a display value corresponding to the input / output ratio. Is displayed on the display unit (2) via the.

In this device, the switches (1L) and (1R) may be push-button switches. However, with this type of switch, anyone can perform an input operation, so that the set value can be changed by an outsider. In this example, switches for performing a special input operation are used as the switches (1L) and (1R) so that this inconvenience can be avoided.

4 shows the appearance of the frequency measuring device of this example, FIG. 4A is a perspective view of the device viewed from the front panel side, and FIG. 4B is a diagram for explaining how to input. is there.

In FIG. 4A, (21) shows the housing of the device as a whole, and (22) shows the front panel. In this example, a liquid crystal display section (23) corresponding to the display section (2) is provided on the front panel (22).

In the case of this example, marks (24M) and (25M) as shown in FIG. B are provided on the left and right surfaces of the liquid crystal display section (23) of the front panel (22). The switches (1L) and (1R) close to the panel (22) are provided on the rear side of the housing (21) of the front panel (22) corresponding to the positions of the marks (24M) and (25M). Reed switches (24) and (25) are provided as shown in FIG. Although not shown, the reed switches (24) and (25) are connected to timer circuits (4) and (8) in the housing (21). Mark (24M) (25M) is a reed switch (24)
It indicates the position of (25).

The mark (24M) (25M) can also serve as, for example, a company mark or other display.

Using the marks (24M) and (25M) as a mark, information is input by the reed switches (24) and (25) as follows.

That is, as shown in FIG. 4B, the person who inputs information places a magnetic field source, in this case, a permanent magnet (2
7) and bring it close to the mark (24M). Then
The induced current flows through the coil of the reed switch (24), and the reed switch (24) is turned on. Next, the permanent magnet (27)
The reed switch (24) returns to off when the distance is increased. Similarly, the reed switch (25) can be turned on / off by moving the permanent magnet (7) closer or farther away, thereby enabling information input operation. Then, the long ON operation is performed by increasing the time in which the permanent magnet (27) is approached, and the short ON operation is performed by shortening the time. Note that a Hall element may be provided instead of the reed switches (24) and (25), and the long ON and the short ON may be detected based on the output voltage of the Hall element.

Further, an electromagnet may be used in place of the permanent magnet (27), and the long ON and the short ON may be performed according to the length of the ON time of the power supply applied to the electromagnet.

Next, the numerical value setting operation in this example and the display at that time will be described below with reference to FIG.

First, the reed switch (24), that is, the switch (1L) is turned on for a long time by bringing the magnet (7) close to the mark (24M). Then, the output mode signal MODE of the mode setting circuit (5) enters the state of the input setting mode. In this input setting mode, a 5-digit Japanese character segment of the display unit (2) is used, and a character [INPUT] indicating the input setting mode is displayed as shown in FIG. 2B. At this time, as shown in FIG. 5, the character [INPU
T] and a numerical value and a 5-digit numerical value (input value) from the decimal point position setting circuit (7) are displayed alternately. In this case, the character display time is 0.1 to 0.2 seconds, and the numerical value display time is 1 second to 1.
It is set to 2 seconds, and the numerical value of the digit which can be reset among the five digits is made to blink twice at 3 to 4 Hz. Initially, this input numerical value is stored in memory (9)
Is displayed. At first, the leftmost digit of the five-digit numerical value blinks at 3 to 4 Hz (the numerical value "4" in FIG. 5). From this state, the permanent magnet (7) is brought closer to the mark (25M) on the right side, and the reed switch (25), that is, the switch (1R) is turned on or short-on, or both are used. Set the leftmost digit blinking at 4Hz to the value "1".

Next, when the switch (lL) is turned on for a short time, the blinking digit in the numerical display for 1.0 to 1.2 seconds shifts to the digit on the right as shown in FIG. Therefore, the switch (1R) is turned on long or short, or both are used, and the value of this digit is set to "2". In the same way, switch (1
L) is turned on for a short time and the blinking digit is shifted to the right sequentially, and the value of that digit is set with the switch (1R).

After setting the rightmost digit in this way, when the switch (1L) is further turned on for a short time, the decimal point blinks twice as shown in FIG. When the switch (1R) is turned on short or long, the decimal point position changes.
The decimal point should be at the position of "1.2345".

Thus, the input setting mode ends. Then, when the switch (1L) is turned on for a long time, the mode setting circuit (5)
The output mode signal MODE becomes the display value setting mode. When the mode is changed, the input value of “1.2345” is transferred to the input value storage unit (9I) of the memory (9) and written prior to the change.

Then, when the display value setting mode is set, a character [DISPL] indicating the display setting mode is displayed as shown in FIG. 2C by using the 5-digit Japanese character segment of the display section (2). At this time, as shown in FIG.
L] and a five-digit numerical value (display value) are alternately displayed with the same time relationship as in the input setting mode, and the digit of the set numerical value blinks at 3 to 4 Hz. As the display value, first, the previous set display value from the storage unit (9D) of the memory (9) is displayed, and the leftmost digit blinks. Thereafter, [3741.7] is set as the display value in the same manner as when the input value is set, and the display value setting is completed.

When this is completed, when the switch (1L) is finally turned on for a long time, the character [OP] is displayed on the five-digit display portion as shown in FIG. 5, indicating that the frequency measurement mode has been entered.
When changing the mode, set "3741.7" prior to the mode change.
Is written to the storage unit (9D) of the memory (9). After 2 seconds, the display of this character [OP] disappears, and as described above, the output display frequency is calculated by the calculated value of the input value: displayed value ratio, and the calculated output value is displayed in 5 digits. Displayed in the section.

As described above, the specific frequency value of the input frequency,
By setting the output display frequency value at the input frequency, the ratio between the two is automatically calculated. And
In measuring the input frequency, an output display value is calculated from the measured input frequency based on this ratio, and the output display value is displayed on the display unit.

Note that the embodiment shown in FIG. 1 can be easily realized substantially by using a microcomputer, and each block is equivalent to a function expressed by hardware in the microcomputer.

In this example, the output is displayed, but if an output voltage corresponding to the frequency is obtained in addition to this display, the output voltage is obtained from the calculated output.

〔The invention's effect〕

According to the present invention, instead of displaying the input measurement frequency as it is, for example, when converting to a predetermined unit or displaying the output display value at a predetermined ratio, it is not necessary to determine and set the conversion ratio. Since it is only necessary to set the input value and the output value, the setting can be easily performed. Further, by setting the input value and the output value, the ratio is automatically calculated, and the output value is obtained from the calculated value. There is no mistake or setting error, and the conversion is performed accurately.
Further, the setting accuracy can be improved as compared with the case where the ratio itself is input.

[Brief description of the drawings]

FIG. 1 is a block diagram of an example of the apparatus of the present invention, and FIGS. 2 to 5 are views for explaining the apparatus. (1L) and (1R) are switches for setting numerical values, (2) is a display unit, (3) is a display control circuit, (9) is a memory, and (10)
Is a ratio calculation circuit, and (12) is a display value calculation circuit.

Claims (1)

(57) [Claims] Means for setting numerical information related to an input frequency value; means for setting information on an electrical output value or an output display numerical value having a functional relationship with the input frequency value; Means for calculating an input / output ratio from the input signal, and a frequency measuring device which obtains an electrical output or a display output while maintaining the input frequency information and the specified functional relationship based on the calculation result.