JPH01118772A - Indicating instrument - Google Patents

Abstract

PURPOSE:To improve an instrument driving signal with good response by providing FV-converting functions which differ in time constant and using a specific F-V conversion output corresponding to the frequency of input pulses as the instrument driving signal. CONSTITUTION:A pulse signal (a) from an object of measurement is inputted to an F-V conversion part 1 and 1' and converted into voltage signals (c) and (c') corresponding to the frequency of the signal (a). A selection part 2 receives the signals (c) and (c') and generates a switch signal (d) which turns on a switch circuit part 3 and turns off a switch circuit part 3' so that when the signal (a) is lower than a predetermined reference frequency, the signal (c) of the conversion part 1 with a large time constant becomes the instrument driving signal (b) to a driving part B. When the frequency of the signal (a) is higher, on the other hand, an opposite signal is generated to turn off the circuit part 3 and turn on the circuit 3' so that the signal (c') of the conversion part 1' with a small time constant becomes the signal (b) to the driving part B. Thus, the instrument driving signal with good response is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an indicator that displays vehicle speed, engine rotational speed, and other information.

(Prior art) The method of displaying vehicle speed, engine rotation speed, etc. is generally performed by attaching a pulse generator to the object to be measured, generating pulses with a frequency corresponding to the rotation speed of the object to be measured, and generating a pulse signal. After performing predetermined waveform shaping, frequency-voltage conversion (hereinafter F
-V conversion) is performed, and the voltage corresponding to the frequency, that is, the value to be displayed on the instrument to be measured, is set as voltage No. 41, and the appropriate instrument is set to wA? based on the voltage signal. It is something to do.

Note that the drive section of the meter varies depending on the type of indicating meter, and in some cases, the voltage No. 41 is amplified to directly drive the meter, and in some cases, as in the case of a crossed coil type meter, a predetermined drive unit based on the voltage signal is used. When converting and driving an instrument (
(Refer to Japanese Patent Application Laid-open No. 120063/1983).

(Problems to be Solved or Solved by the Invention) As a means for displaying vehicle speed, engine rotation speed, etc., as described above, in a device to be measured with a pulse generator attached, If we look at the pulse frequency of, for example, the vehicle speed, we can see that the vehicle speed is 60/h,
If the axle rotation speed is 637 rpm + m and 4 pulses are generated every - rotation, then! &Large vehicle speed is 120km/
h, a pulse with a frequency of approximately 84.9 Hz will be output from the object to be measured at the maximum vehicle speed. In other words, the frequency of the pulse output from the object to be measured is 0 to 84.9Hz.
This is a very large range.

Considering the F-V conversion in the above frequency range from the point of view of the time constant of the conversion circuit, for example, a constant Ti ? This is the simplest F-V conversion circuit in which the lZ source I is connected to a parallel circuit of a resistor R and a capacitor C. When there is a low-frequency pulse input, the voltage output V when the time constant of the parallel circuit is large is: As shown in Figure 6, the difference Vx between the maximum voltage when one-shot energization is performed by pulse input and the minimum voltage that decays until the next pulse input
is small. On the other hand, when the time constant of the parallel circuit is small, the voltage output VB is the difference between the maximum voltage and the minimum voltage V'x
becomes very large, and this causes the so-called needle runout problem in which the meter indicator driven in response to the voltage output VB fluctuates.

Also, considering the case where the frequency of the pulse input is high, as shown in Figure 7, when the time constant is large, the voltage output V person will not change even if the input pulse frequency fluctuates. Because it is slow, following instructions becomes a problem. On the other hand, when the time constant is small, the voltage output VB responds immediately to changes in frequency.

Therefore, if the input from the object to be measured is a pulse frequency that is a time function, and you want to display an instruction by converting this into F-V, if the time constant of the F-V converter is large, the response will be poor. Further, when the time constant of the F-V conversion section is small, the response is good, but when the frequency of the pulse input is low, there is a problem in that a needle runout phenomenon occurs.

(Means for Solving the Problems) In view of the above-mentioned problems, the present invention provides an instrument in which the conventional F-V conversion section is replaced with a selective conversion section having a plurality of F-V conversion functions with different time constants. It is something. That is, the indicating instrument according to the present invention is an indicating instrument in which the input from the object to be measured is a pulse of a time function, and the input is converted into a voltage output to cause the display section to respond. The present invention is characterized by comprising a selection conversion section having a voltage conversion function and a selection function of selecting a conversion output for driving an instrument in correspondence with an input pulse frequency.

(Function) When receiving an input pulse, it performs F-V conversion with different time constants, and also measures the input pulse by directly measuring the input pulse frequency or comparing the F-■ conversion output. The output is F-V converted by a conversion circuit with an appropriate time constant corresponding to the frequency of the input pulse and is sent to the next drive unit as the output (instrument drive signal) of the selection conversion unit. It is something. That is, when the frequency of the input pulse is low, the output converted by the F-V conversion circuit with a large time constant is selected as the output of the conversion section, and when the frequency of the manual pulse is high, the output converted by the F-V conversion circuit with a small time constant is used. By using the output of the selected converter as the output of the selected converter, needle runout does not occur even if the frequency of the input pulse is low.
In addition, it was possible to obtain a 4= meter drive using F-V conversion with good response.

(Example) Next, examples of the present invention will be described.

The indicating instrument according to the present invention is composed of a selection conversion section A, a driving section B, and a display section C. The selection conversion section A receives a pulse signal a in the form of a frequency to display a value to be displayed from an object to be measured. , and outputs an instrument drive signal to the drive section B, the details of which will be described later. I! If! ! II! S B
receives the meter drive signal and supplies a drive current to the pointer drive coil, etc. in the display section C, and is determined depending on the type of the display section C, that is, the type of the meter. For example, if the display part C is a crossed coil type meter, when the drive part B receives the driving signal, it will perform arithmetic processing depending on the magnitude of the signal and output the current to be passed through each crossed coil, and the display part C will In the case of a moving coil type instrument, the drive section B outputs such that a current corresponding to the magnitude of the signal flows through the moving coil.

As illustrated in FIG. 2, the selection conversion section A consists of two F-V conversion circuit sections 1.1 with different time constants, a selection section 2, and a switch circuit section 3.3. 1.1 is composed of a well-known F-V conversion circuit, which receives pulse signal a from the object to be measured, outputs voltage signals c and c' corresponding to the frequency of pulse No. 42 a, and performs selection. 2 and the switch circuit section 3.3'. Selection section 2
For example, by comparing the voltage signals c and c', there is a means to determine whether the frequency of the input pulse is low or high, such as whether there is a difference between the two at a certain time or whether the voltage exceeds a certain value. The determination is indicated by the output form (high or low) of the switch signal d which is the output of the selection section 2. The switch circuit section 3.3' is connected to each F-V
It receives the voltage signals c and c' of the conversion section and performs a switching operation to determine whether or not to transmit them to the drive section B. It is operated by the switch signal d, and if both switch circuit sections 3.3 If both switches are turned on by a high signal, an N07 circuit is provided in the path of one switch signal d.

When the pulse signal a from the object to be measured is input to the F-V converter 1.1, it is converted into a voltage signal cSc' corresponding to the frequency of the pulse signal a, and the selector 2 converts the voltage signal c and c#, and when the frequency of pulse No. 41 a is lower than the predetermined reference frequency, for example, 20 Hz or less, the voltage signal C of the F-V converter 1 with a large time constant is applied to the meter to the drive unit B. The switch circuit section 3 is turned on so that the drive signal is turned on, and the switch circuit section 3 is turned off.
A switch signal d to set the F state is issued, and a pulse signal a is issued conversely.
If the frequency of This is to bring the switch circuit 3 into the ON state. Therefore, when the input frequency of pulse No. 41 is low, the voltage No. 45 converted by the F-V conversion circuit with a large time constant becomes the voltage No. 9 for driving the instrument, and conversely, when the input frequency is high, the time constant The voltage signal converted by the small F-V conversion circuit is input to the drive unit B as a meter drive signal.

Note that the configuration of the selective conversion section is not limited to that described above; for example, as shown in FIG. 4 is provided, and the F-V conversion section 1.
A switch, part 3, interposed between 1 and drive part B,
It may be controlled by a selection section 2' which receives input from the frequency counter 4 and selects an operation. Furthermore, as shown in FIG. 4, a selection F-V is provided instead of the frequency counter 4.
The present invention has a plurality of F-V conversion functions with different time constants, and a converter circuit 1 may be provided. Any configuration may be used as long as it can determine which F-■ conversion output is to be used as the signal output for driving one device.

(Effects of the Invention) As described above, the present invention provides an indicating instrument in which the input from the object to be measured is in the form of a pulse signal frequency, by providing an F-v conversion function with a plurality of different time constants. Calculate the conversion output after the predetermined F-V conversion corresponding to the frequency of ? This is an I-type for fJ drive, which improves needle runout caused by F-V conversion when the input pulse frequency is low and poor response when the input pulse is high frequency.

[Brief explanation of the drawing]

Fig. 1 is a basic program diagram for implementing the instrument of the present invention, Fig. 2 is a detailed block diagram thereof, Figs. 3 and 4 are block diagrams showing another embodiment of the selection converter, and Fig. 5 is a block diagram showing another embodiment of the selection converter. An example of an F-V conversion circuit is shown, with FIG. 6 showing the conversion output when a low frequency input is received, and FIG. 7 showing the same high frequency input. 1.1', 1f is the F-V conversion circuit section 2.2' is the selection section 3, /, 3' is the switch circuit section 4 is the frequency counter A, the selection conversion section B is the drive section C is the display section Patent Applicant Nippon Seiki Co., Ltd. Figure 4 Figure 5 Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] An indicating instrument whose input from an object to be measured is a pulse of a time function and which converts the input into a voltage output to cause a display section to respond, has a plurality of frequency-voltage conversion functions with different time constants. and a selection conversion section having a selection function for selecting a conversion output for driving the meter in correspondence with an input pulse frequency.