JPS5826384Y2 - Cross coil indicator - Google Patents

Description

[Detailed description of the invention] This invention relates to a cross-coil type indicating instrument suitable for, for example, an automobile tachometer or speedometer, which receives a pulse signal whose frequency changes according to changes in the state of the object to be measured. .

This type of indicating instrument is desired to be able to efficiently process input measurement signals and to be capable of wide-angle indication.

Conventional crossed-coil type indicating instruments are configured to process measurement input signals in an analog manner, for example, by complexly combining circuit elements such as multiple Zener diodes, and using their characteristics to provide wide-angle indications. It looks like this.

However, with such a configuration, it is not only impossible to obtain good indication characteristics over a wide indication range due to variations in the characteristics of the circuit elements, but also it is necessary to select and adjust the elements in order to eliminate the variations in the characteristics. The disadvantage was that it required a lot of man-hours.

This idea makes signal processing more efficient by digitally processing the measurement input signal, uses an up-down counter, and uses the repeated up-down operations of the up-down counter to improve the indication characteristics due to variations in circuit elements. It is an object of the present invention to provide a crossed coil type indicating instrument that is free from defective states.

Hereinafter, one embodiment of this invention will be described in detail with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a waveform shaping circuit, and a pulse signal to be measured whose frequency changes according to changes in the state of the object to be measured is supplied from a terminal P.

The waveform shaping circuit 1 removes noise components from the pulse signal under test and matches the voltage level with the signal processing circuit at the subsequent stage.

The waveform shaping output is then supplied to the frequency-voltage converter 2 and converted into a voltage signal, and this converted signal is further supplied to the voltage-frequency converter 3 to multiply the number of pulses of the pulse signal under test. .

This multiplied signal is then supplied to the gate circuit 6.

On the other hand, 4 is an oscillator that supplies a reference signal to the control signal generator 5 at the next stage.

The control signal generator 5 generates a subsequent gate circuit 6, an up/down counter 1, and a latch circuit 8 based on the reference signal.
, generates a timely control signal to control the output control section 13, and supplies it to each section.

The gate circuit 6 converts the pulse signal to be measured (FIG. 2g) supplied from the voltage-frequency converter 3 into the control signal generator 5.
The gate output signal (FIG. 2g) is compared with the gate signal (FIG. 2b) supplied by the up/down counter 7.

The up/down counter 1 counts the gate output by performing up/down operations for each full counter.

The latch circuit 8 receives the output signal (
The binary output signal corresponding to the counter output shown in Fig. 2f) is output from the control signal generator 5 as a latch signal (Fig. 2g)
latches.

The up/down counter 1 is switched up/down by an up/down switching signal (Fig. 2g) from an output control section 13 (described later), which is controlled by the carry signal, and also by a clear signal from the control signal generator 5. It is cleared after latching by the signal (FIG. 2d).

This operation is repeated continuously.

The count output latched by the latch circuit 8 and its inverted output are subjected to binary-to-analog conversion via the first DA converter 9 and the second DA converter 10, and then
This analog output (third diagram and i) is supplied to the first and second output sections 11 and 12.

The first output section 11 and the second output section 12 are connected to the first output section 11 and the second output section 12, respectively.
The output signals of the third diagram and i from the D-A converter 9 and the second D-A converter 10 are changed into polar waveforms by the polarity switching signal (j and k in FIG. 3) of the output control section 13. After converting and further current amplification, the crossed coils 14 and 1
5.

As a result, the intersecting coils 14 and 15 are connected to the solid line 14' in FIG.
A coil current flows as indicated by the dotted line 15', and a composite magnetic field acts on the indicator magnet 16 in a direction corresponding to the magnitude of the coil current, causing the indicator magnet 16 to rotate as shown in the opening in Figure 4. to specify the measurement pulse signal.

In addition, 17 is a switch that cuts off the latch signal (Fig. 2g) that controls the latch operation of the latch circuit 8 from the outside.
The latch operation of the latch circuit 8 is stopped.

If the latch operation is stopped, the latch output does not change, so the previously indicated position can remain.

In the above embodiment, a polarized triangular wave is applied to the crossing coils 14 and 15, but it is also possible to apply a sine wave or a cosine wave, and in that case, the output section 11 This can be similarly realized by correcting the counter output or latch output using, for example, a ROM so that the signal of .degree.12 has sine wave and cosine wave characteristics.

Further, in the above embodiment, the number of pulses of the pulse signal to be measured is multiplied by the frequency-voltage converter 2 and the voltage-frequency converter 3 so that wide-angle indication can be performed with a short sampling time. If the number of pulses is sufficient, the above converters 2 and 3 can be omitted.

As explained above, according to this invention, the input signal, which is a pulse signal, is processed digitally, so signal processing is more efficient than conventional analog processing, and the engine ignition system and vehicle speed are Ideal for tachometers and speedometers that measure and instruct electrical pulses from sensors.

In addition, since an up-down counter is used and its up-down operation is repeated, there is little effect on the indication characteristics due to variations in circuit elements, and uniform indication can be achieved in any indication quadrant of the indication magnet. characteristics can be obtained.

Furthermore, since it is mainly composed of digital circuits, integration is easy and mass production is excellent, and the instrument itself can be miniaturized.

Further, since a reference signal oscillator is provided, the reference signal can be used as a signal for checking the index.

Furthermore, when the latch operation of the latch circuit is stopped, the latch output of the latch circuit does not change, so the residual instruction function can be provided by a simple operation of cutting off the latch signal.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a cross-coil indicator according to an embodiment of the invention, FIG. 2 is a time chart showing the signal waveforms of the main signals of the above embodiment, and FIG. FIG. 4 is a signal waveform diagram showing the output signal waveforms of the first and second D-A converters and the control signal waveform of the output control section in the above embodiment, and FIG. FIG. 3 is an explanatory diagram showing the relationship between indicator magnets placed under the action of a magnetic field. 5... Control signal generator, 6... Gate circuit, 7...
・Up/down counter, 8...Latch circuit, 9...
・First DA converter, 10... second DA converter, 11... first output section, 12... second output section,
14゜15...Cross coil 16...Indicator magnet.

Claims (2)

[Scope of utility model registration request] (1) A gate circuit 6 that compares a measurement pulse signal whose frequency changes according to changes in the state of the object to be measured with a predetermined gate signal, and the measurement pulse signal that passes through this gate circuit 6 is raised and lowered every full count. An up/down counter 1 that repeatedly performs counting, a latch circuit 8 that latches the output signal of this up/down counter 1 based on a predetermined control signal, and a first latch circuit that converts the output signal of this latch circuit 8 into an analog signal. a D-A converter 9, a second D-A converter 10 that converts the inverted output signal of the latch circuit 8 into an analog signal, and a polarity switching signal corresponding to the up-down operation of the up-down counter 7. an output control section 13 that generates a signal, first and second output circuits 11 and 12 that polarize the output signals of the first and second DA converters 9 and 10 using the polarity switching signal; Output circuit 11.1 of first and second output circuits 11, 12
a pair of crossed coils 1 which receive the output signals of 2 and generate a composite magnetic field in a direction corresponding to the frequency of the measurement pulse signal;
4, 15, and an indicator magnet 16 which indicates a direction corresponding to the frequency of the measurement pulse signal by means of the composite magnetic field of the intersecting coils 14 and 150. (2) The crossed coil type indicator according to claim 1, wherein the latch circuit 8 is configured such that its latch operation can be stopped from the outside.