JPH0766003B2 - Operating state recording / playback device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention records the number of revolutions of an engine and the state of brake pedal operation in an actual running state of an automobile, and reproduces these to reproduce them on the same time axis. The present invention relates to an operating state recording / reproducing device for displaying a graph on the screen.

(Prior Art) Conventionally, in a vehicle driving simulation device or the like,
Perform a pseudo driving operation by grasping the road condition from the scene displayed in front of the driver to be inspected, and calculate the engine speed and running speed of the automobile engine from the operation data of the accelerator pedal and brake pedal at this time. However, there is a device in which these data and a signal corresponding to the operation of the brake pedal are recorded and reproduced later so that the driver's driving skill and driving temperament can be analyzed.

(Problems to be Solved by the Invention) However, in the above-described conventional device, since the vehicle is not actually driven and run, the sense of speed received by the driver to be inspected and the difference in performance that the vehicle has The difference in operation is not clear, and the data does not always accurately reflect the driving skill and driving disposition of the driver to be inspected. For this reason, it has not been possible to accurately analyze the driving skill and driving disposition of the driver to be inspected.

The present invention has been made in view of such circumstances. Therefore, the data of the engine speed and the operation of the brake pedal, which are obtained from an automobile that is actually driven, are recorded, and these are reproduced and reproduced on the same time axis. It is an object of the present invention to provide a driving state recording / reproducing device which displays a graph.

(Means for Solving the Problem) In order to achieve such an object, a driving state storage / reproduction device of the present invention includes a rotation speed detection means for outputting a rotation speed signal having a pulse period corresponding to the rotation speed of an automobile engine. Waveform processing means for converting the rotation speed signal into a modulation signal for outputting a narrow "L" level pulse for each pulse, and brake pedal operation detecting means for outputting a brake signal in response to operation of the brake pedal A carrier selecting means for selecting one of a first frequency signal and a second frequency signal having different frequencies according to the brake signal; a modulating means for modulating the selected frequency signal with the modulation signal; Magnetic recording means for recording the modulated signal on a magnetic tape.

In addition, the modulated signal is converted into a DC voltage according to the pulse cycle by D /
A first D / A conversion circuit for A conversion, a voltage division selection circuit for selecting an appropriate voltage division signal of its output, and a first engine rotation speed display means for displaying the rotation speed according to this voltage division signal. And a first variable that divides the voltage of the pulse output from the pickup clip by the waveform processing means, wherein the rotation speed detection means is a pickup clip that sandwiches a cord on the distributor input side of the engine. The voltage dividing selection circuit is formed by a resistor, an amplifier for amplifying the divided voltage signal, and a one-shot multivibrator that is triggered by the amplified output and outputs a modulated signal of a narrow “L” level pulse. Is set according to the number of cylinders of the engine and the first variable resistor is adjusted so that the display of the first rotation speed display means matches the display of the existing engine tachometer of the automobile. It may be configured to.

And, a modulation signal restoring means for restoring the modulated signal from the modulated signal reproduced by the magnetic recording means, and a D / A conversion of the pulse period of the restored modulation signal into a DC voltage.
D / A converter circuit, a brake signal restoring means for restoring the period of the frequency signal selected according to the brake signal from the modulated signal, the restored brake signal and the second D / A converter circuit And a graph display means for displaying the output of the above as a graph on the same time axis.

Further, a reference signal generating means for outputting a reference signal in which a predetermined frequency signal is modulated with a reference pulse, a changeover switch for selectively changing the reference signal and the reproduced modulated signal, and the second D / A conversion. Second to divide the output of the circuit
And a second engine rotation speed display means for displaying the engine rotation speed according to the divided voltage signal,
Before displaying the graph, the second variable resistor is adjusted while the reference signal is being selected by the changeover switch, and the second engine speed display means provides a predetermined rotation according to the number of cylinders of the engine. The number may be displayed and the magnitude of the output of the second D / A conversion circuit provided to the graph display means may be adjusted.

Further, it can be configured by including an AF amplifier for amplifying the modulated signal reproduced by the magnetic recording means, and a speaker for amplifying the amplified output.

(Operation) The rotation speed signal and the brake signal obtained while actually driving the automobile are recorded as one signal on the magnetic tape.

Also, a pulse corresponding to the ignition noise can be easily obtained from a pickup clip that sandwiches the cord on the distributor input side of the engine. Moreover, by adjusting the first variable resistor, it is possible to adjust at which level of the ignition noise the one-shot multivibrator is triggered. In addition, by selecting a voltage division signal corresponding to the number of cylinders of the engine from the output of the first D / A conversion circuit by the voltage division selection circuit, the number of rotations of the engine can be properly adjusted by the first engine speed display means. Is displayed.

Then, the D / A converted output corresponding to the pulse period of the modulated signal restored from the modulated signal reproduced by the magnetic recording means and the restored brake signal are graphically displayed on the same time axis and The signal correlation becomes clear.

Also, before the graph is displayed, the reference signal is selected by the changeover switch, the output of the D / A conversion circuit is appropriately divided by the second variable resistor, and the result is given to the second engine speed display means to output the engine. If the display according to the number of cylinders is selected, the graph display means is provided with a predetermined output for the engine speed regardless of the difference in the number of cylinders when the modulated signal is selected by the changeover switch. The proper engine speed of the car can be displayed.

Further, by amplifying the modulated signal from the speaker, it is possible to obtain a voice in which the frequency at which the sound breaks changes according to the engine speed and the frequency changes due to the brake pedal operation.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 to 6. FIG. 1 is an overall configuration diagram showing an outline at the time of recording of an operating state recording / reproducing apparatus of the present invention, and FIG.
FIG. 3 is a block circuit diagram of an embodiment of the recorder shown in FIG. 3, and FIG. 3 is a block circuit diagram of an embodiment of a regenerator used at the time of regenerating of the operating state recording / reproducing apparatus of the present invention. FIG. 5 is a time chart for explaining the operation by showing the signal waveforms of the respective parts of the recorder and the regenerator, and FIG. 6 shows the graph display means used when reproducing the operation state recording and reproducing apparatus of the present invention. It is a figure which shows an example of the graph display obtained.

First, the outline of the entire configuration at the time of recording will be described with reference to FIG. In the automobile 10, a video camera 12 as a photographing / recording unit for photographing and recording a front scene is installed facing forward. Signals from the recorder 14 are applied to the Rch and Lch audio input terminals of the video camera 12, respectively. Engine by the audio signal recording part of the video camera 12
Magnetic recording means for recording 16 rotation speed signals and the like is configured. Then, the recording machine 14 is provided with a rotation speed signal obtained from a pickup clip 20 as rotation speed detecting means for sandwiching the cord 18 on the distributor input side for supplying a spark current to an ignition plug of the engine 16. Further, the recording device 14 is provided with a brake signal from a switch 23 as a brake pedal operation detecting means which is turned on / off according to an operation of the brake pedal 22. Then, mark 26,26 on the two sides of the concentric circle on the side of the tire 24.
Is attached, the optical sensor 28 as a speed detecting means is arranged in the tire house of the automobile facing these marks 26, 26, and each time the marks 26, 26 correspond to the optical sensor 28, they are connected to the optical sensor 28. A pulsed speed signal is given to the recording machine 14 from the amplifier unit 30. Further, a switch 32 for starting a stop instruction is connected to the recording machine 14,
Further, a stop instruction lamp 34 that is turned on after a lapse of a predetermined time from the operation of the switch 32 is connected.

Next, the configuration of the recording machine 14 will be described with reference to FIG. 2, FIG. 4 and FIG. The spark current given to the ignition from the code 18 on the input side of the distributor is radiated fairly strongly, and by simply sandwiching the code 18 with the pickup clip 20, a sufficiently large level of pulse shape according to the rotation speed of the engine 16 is obtained. A rotation speed signal as shown in FIG. 4 (a) is obtained at the rotation speed signal input terminal 36. The rotation speed signal is divided by the first variable resistor 38, and the divided signal is amplified by the amplifier 40 and given to the first one-shot multivibrator 42 as a trigger. The first one-shot multivibrator 42 outputs a narrow "L" level pulse as shown in FIG. 4 (b) every time a trigger is applied, and this pulse-like modulated signal is the first modulating circuit. 44 and the first D / A conversion circuit 46. In addition,
A waveform processing means is formed by the first variable resistor 38, the amplifier 40, and the first one-shot multivibrator 42.

Further, a brake signal that is turned on / off by operating the brake pedal 22 is given to the brake signal input terminal 48, and the waveform shaping circuit 50 removes the waveform shaping and chattering, and a signal as shown in FIG. 4 (c). As a control signal to the first carrier selection circuit 52. The first carrier wave selection circuit 52 is supplied with a first frequency signal of, for example, 10 KHz from the first oscillation circuit 54, and is supplied with a second frequency signal of, for example, 5 KHz from the second oscillation circuit 56. 10KH with the brake pedal 22 not depressed
5KH when the first frequency signal of z is selected and stepped on
Select the second frequency signal of z. Then, one of the selected frequency signals is given to the first modulation circuit 46, A1 modulated by the modulation signal from the first one-shot multivibrator 42, and the modulated signal as shown in FIG. 4 (d). Is output as. This modulated signal is output from the Rch output terminal 56
To the Rch of the audio input terminal of the video camera 12. Further, the first D / A conversion circuit 46 outputs a DC voltage according to the pulse cycle, and this voltage value is a voltage division selection circuit 47.
The divided pressure signal corresponding to the number of cylinders of the engine 16 is selected, and the number of revolutions of the engine 16 is displayed by a number or the like by the first engine revolution number display means 60 according to this divided pressure signal.

In addition, from the amplifier unit 30 connected to the optical sensor 28,
A pulse-like speed signal as shown in FIG. 5 (h) corresponding to the rotational speed of the tire 24, that is, the traveling speed of the automobile 10 is obtained at the speed signal input terminal 62. The section x in FIG. 5 (h) is an amplifier unit when the automobile 10 is at a low speed and the optical sensor 28 is in a state of corresponding to the marks 26, 26 for a long time.
Output from 30. This speed signal is given to the second one-shot multivibrator 64 as a trigger. The second one-shot multivibrator 64 outputs a narrow "L" level pulse as shown in FIG. 5 (i) every time a trigger is given, and this pulse-like modulated signal is used as the second modulating circuit. 66 and the first inverting circuit 68.
The second one-shot multivibrator 64 has a retrigger function and outputs a pulse corresponding to the length of the section x to the input such as the section x in FIG. 5 (h). Then, the second modulation circuit 66 is provided with a 10
KHz first frequency signal or 5 from second oscillator circuit 56
Either one of the second frequency signals of KHz is selected by the second carrier selection circuit 70 and given. Here, the second carrier selection circuit 70 is controlled by a stop instruction signal described later, selects the first frequency signal of 10 KHz with the stop instruction signal output, and outputs the stop instruction signal without output. Selects the second frequency signal of 5 KHz. Therefore, the second
As shown in FIG. 5 (k), the modulation circuit 66 of FIG. 5 outputs a modulated signal in which the carrier is A1 modulated by the modulation signal output from the second one-shot multivibrator 64, and is further supplied to the adding circuit 74. This adder circuit 74 has a third
A third frequency signal of, for example, 18 KHz is applied from the oscillator circuit 74 of FIG. 3 to the modulated signal such as the third frequency signal shown in FIG.
The signal to be added on which the frequency signal of is superimposed is output. This added signal is transferred to the video camera 12 via the Lch output terminal 78.
It is given to the Lch of the audio input terminal of. The reason why the third frequency signal of 18 KHz is added is to prevent the AGC circuit of the video camera 12 from excessively operating in the non-signal section of the A1 modulated signal. A signal obtained by inverting the output of the second one-shot multivibrator 64 by the first inverting circuit 68 is given to the third one-shot multivibrator 80 as a trigger. This third one-shot multivibrator 80 works in up-edge,
It outputs a pulse wider than the one-shot multivibrator 64 pulse. Then, the output of the third one-shot multivibrator 80 is given to the speed lamp 82 and is turned on only while the pulse is present. Here, the reason why the pulse width of the third one-shot multivibrator 80 is widened is to appropriately lengthen the time during which the speed lamp 82 is turned on.

The stop signal instructing means 72 is a timer provided with a starting switch 32 and a second variable resistor 86 for adjusting time, and when a predetermined time elapses after operating the starting switch 32,
An "H" level stop instruction signal is output as shown in FIG. 9 (j) and is supplied to the second carrier selection circuit 70, and the stop instruction lamp 34 is lit via the stop instruction signal output terminal 88.

Next, a playback device 90 for displaying a graph from the playback signals of the signals recorded on the audio Rch and Lch of the video camera 12
The graph display means 112 will be described with reference to FIGS. Rc for audio signal of video camera 12
The playback signal from h is 2 via the Rch input terminal 92 of the playback device 90.
The reproduced signal from the Lch is given to the a contact of one circuit of the circuit 2-contact changeover switch 98, and the reproduced signal from the Lch is input to the Lch input terminal 94 of the reproducer 90.
Is applied to the a contact of the other circuit of the changeover switch 98 via. Then, the reference signal generated from the reference signal generating means 96 is applied to the b-contact of one circuit and the b-contact of the other circuit of the changeover switch 98, for example, by modulating the frequency signal of 5 KHz with the pulse of the reference cycle. The Rch reproduction signal (FIG. 4 (d)) selected by the changeover switch 98 is the first 5 KHz miss pulse detector 100 (missing as the modulation signal restoring means.
pulse detector) and the first 10KHz miss pulse detector
Given to 102. These miss pulse detectors 100, 102
Operates so as to output an "H" level signal when the input signal does not include a frequency signal having a predetermined frequency or higher. Therefore, the "H" level pulse is output from the first 5 KHz miss pulse detector 100 during the period of no signal in which the carrier wave due to A1 modulation is interrupted, that is, while the pulse of the first one-shot multivibrator 42 is present. The modulated signal as shown in FIG. 9E is restored and output. The restored modulation signal is converted by the second D / A conversion circuit 104 into a DC voltage corresponding to the pulse period, and further divided by the third variable resistor 106, and the divided signal is converted into the second divided voltage. It is given to the engine speed display means 108. Further, this divided voltage signal is given to the graph display means 112 via the rotation speed signal output terminal 110. Also, the first 1 to which the playback signal of Rch is given
“H” is output from the 0 KHz miss pulse detector 102 while the pulse of the first one-shot multivibrator 42 is present and while the carrier of the reproduction signal is the second frequency signal of 5 KHz.
When a signal such as the one shown in Fig. 4 (f) that reaches the level is output,
It is provided to the KHz low pass filter 114. And this 10KH
From the z low-pass filter 114, as shown in FIG.
The brake signal that is at the "H" level is restored and output only while the passage of the pulse corresponding to the one-shot multi-vibrator 42 is blocked and the second frequency signal is used as the carrier,
It is given to the graph display means 112 via the brake signal output terminal 116. The first 10KHz miss pulse detector 102
And the 10 KHz low-pass filter 114 form a brake signal restoring means.

The Lch reproduction signal selected by the changeover switch 98 (Fig. 5 (l)) is given to the 18KHz low-pass filter 118 that blocks passage of 18KHz, and is restored to the signal of Fig. 5 (k). Two 5 KHz miss pulse detectors 120 and a second 10 KHz miss pulse detector 122 are provided. Then, the second 5KHz
The miss pulse detector 120 outputs a signal such as that shown in FIG. 5 (m) which becomes “H” level while the pulse of the second one-shot multivibrator 64 is present, and the third D /
It is supplied to the A conversion circuit 124, converted into a DC voltage according to the pulse cycle, further divided by the fourth variable resistor 126, and the divided signal is given to the speed display means 128 to drive the automobile 10. Display the speed with numbers. Also,
This divided voltage signal is given to the graph display means 112 via the speed signal output terminal 130. Then, the second 10 KHz miss pulse detector 122 outputs a signal as shown in FIG. 5 (o), which is further inverted by the second inverting circuit 132 to give a stop instruction signal as shown in FIG. 5 (p). It is given to the graph display means 112 via the output terminal 134.

Furthermore, the signal from the common terminal of the Rch circuit of the changeover switch 98 is transferred to the AF amplifier via the resistor 136 and the monitor switch 138.
The amplified signal is applied to the speaker 140, and the amplified signal is applied to the speaker 142.

In such a configuration, first, the automobile 10 is set in an idling state, the voltage division selection circuit 47 of the recording machine 14 is set according to the number of cylinders of the engine 16, and the first variable resistor 38 is adjusted to adjust the first engine. The display of the rotation speed display means 60 is an automobile.
10 Match the display of the tachometer provided by itself. With these settings and adjustments, the difference in the number of ignition noises due to the number of cylinders and the difference in the output voltage of the first D / A conversion circuit 46 was corrected for the engine speed display. Adjust the level of the resulting ignition noise that triggers the first one-shot multivibrator 42. And the car
The video camera 12 sends the rotation speed signal, brake signal, speed signal, and stop instruction signal while actually driving 10
To be recorded as a voice signal. Where the video camera 12
The signal recorded on the Rch includes the rotation speed signal according to the period of the no-signal section of the A1 modulated carrier wave and the brake signal information due to switching between the first and second frequency signals. In addition, the Lch signal includes information on the speed signal according to the period of the no-signal section of the A1 modulated carrier wave and the stop instruction signal by switching between the first and second frequency signals.

In order to display the signal thus recorded in the form of a graph, first, the reference signal is selected by the changeover switch 98 of the regenerator 90, the third variable resistor 106 is adjusted, and the number of cylinders of the engine 16 of the automobile 10 is adjusted. The engine speed is displayed on the second engine speed display means 108 to adjust the output of the second D / A conversion circuit 104 for the cycle of the pulse included in the reference signal. This is to correct the difference in the number of ignition noises obtained by one revolution of the engine 16 depending on the number of cylinders. Instead of the correction by the third variable resistor 106, the pulse output from the first 5KHz miss pulse detector 100 is divided by the variable frequency divider according to the number of cylinders, and the second D / A conversion is performed. It may be given to the circuit 114.

Similarly, adjust the fourth variable resistor 126 to adjust the tire 2
The speed corresponding to the outer diameter of 4 is displayed on the speed display means 128, and the third D / for the cycle of the pulse included in the reference signal is displayed.
The output of the A conversion circuit 124 is adjusted. This is to correct that the traveling distance in one rotation varies depending on the outer diameter of the tire 24, and a list corresponding to the outer diameter of the tire 24 may be created in advance. Of course, the speed to be set differs depending on the number of marks 26 attached to the tire 24.

Next, the changeover switch 98 is returned so as to select the reproduction signal from the video camera 12, and the graph display means 112 displays a graph simultaneously with the reproduction of the audio signal by the video camera 12. If the monitor switch 138 is turned on at the same time, the period at which the sound breaks changes depending on the rotation speed of the engine 16 and the operation of the brake pedal 22 causes 10 KHz.
The voice that can be switched between 5 kHz and 5 KHz is amplified by the speaker 142, and the running state of the automobile 10 can be grasped by the sound. Then, the graph display means 112 outputs a graph in which the rotation speed signal, the speed signal, the brake signal, and the stop instruction signal of the engine 16 as shown in FIG. 6 are displayed on the same time axis. From the correlation of these signals, the driving characteristics of the driver to be inspected can be analyzed while further reproducing the scene captured by the video camera 12 for reference. Then, by measuring the time t from the output of the stop instruction signal to the operation of the brake pedal 22, the reaction speed of the driver to be inspected can be checked. Furthermore, due to changes in the engine 16 speed and speed, etc., the accelerator pedal and brake pedal 22
Various characteristics such as responsiveness to the operation of can be objectively known.

In the above embodiment, the Rch and Lch outputs of the recorder 14 are used as the audio input signals of the video camera 12, but the present invention is not limited to this, and may be recorded on a tape recorder or the like. Further, in order to record four pieces of information on two audio tracks on the magnetic tape of the video camera 12, two pieces of information are superposed on two output signals of Rch and Lch of the recorder 14, respectively. The tape recorder may be used to record each information on one track on the magnetic tape. Further, when two pieces of information are superimposed on one output signal, the rotation speed signal and the stop instruction signal may be combined, and the speed signal and the brake signal may be combined. And
In the regenerator 90, the means for separating the respective information from the Rch and Lch reproduction signals is not limited to the above embodiment, and may be configured by using an appropriate filter and detection means. Also,
The first, second, and third frequency signals are not limited to 10 KHz, 5 KHz, and 18 KHz, and may be set appropriately, and the predetermined frequencies of the miss pulse detectors 100, 102, 120, 122 may be set according to these frequencies. In addition, graph display means
As for 112, it is sufficient that each signal can be displayed on the same time axis, and a graph may be displayed using a CRT or the like. Also, the method of detecting the engine speed and the vehicle speed of the engine 16 is not limited to the above-described embodiment, and an existing meter or the like may be used in the automobile 10, or may be detected by another appropriate method. Further, it goes without saying that the shooting and recording of the scene in front of the automobile 10 is not limited to the video camera 12.

(Effects of the Invention) Since the operating state recording / reproducing apparatus of the present invention is configured as described above, it has the following effects.

An engine speed signal and a brake signal obtained by actually driving a vehicle can be recorded on a magnetic tape with a simple structure.

Moreover, a pulse-shaped rotation speed signal corresponding to the ignition noise can be easily obtained from a pickup clip sandwiching the cord on the distributor input side of the engine, no modification of the automobile is required, and the structure of the rotation speed detection means is extremely high. It's easy. Furthermore, by adjusting the first variable resistor, it is possible to set at what level of the pulse the one-shot multivibrator is triggered, which includes many pulsating flow components and the amplitude changes drastically to change from the ignition noise to the engine speed. A modulated signal having a corresponding pulse period can be obtained. In addition, the output of the D / A conversion circuit is set to a voltage division signal according to the number of cylinders by the voltage division selection circuit in response to the difference in the number of ignition noises generated by one revolution of the engine depending on the number of cylinders. It is possible to properly display the engine speed even in an automobile with the number of cylinders.

The change in engine speed and the operation of the brake pedal are displayed graphically on the same time axis, so the correlation between these two signals becomes clear, and the correlation between the operation of the accelerator pedal and the brake pedal becomes clear. Became clear,
This is useful for analyzing the driving skill and driving disposition of the driver to be inspected.

Further, before displaying the graph, the reference signal is selected by the changeover switch to adjust the second variable resistor, and the second variable resistor is adjusted.
If the output of the D / A conversion circuit of is appropriately divided and displayed according to the number of cylinders with respect to the reference signal by the second engine speed display means, when the modulated signal is selected by the changeover switch, Even if the number of cylinders differs with respect to this modulated signal, a predetermined output with respect to the engine speed is given to the graph display means, and the second engine speed display means is used even for automobiles with different number of cylinders. The engine speed can be displayed appropriately.

Further, if the modulated signal is amplified by the speaker, the change in the engine speed and the operation state of the brake pedal can be recognized by sound.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing an outline at the time of recording of an operating state recording / reproducing apparatus of the present invention, and FIG. 2 is a block circuit diagram of an embodiment of the recording machine of FIG. FIG. 4 is a block circuit diagram of an embodiment of a regenerator used at the time of regenerating the operating condition recording / reproducing apparatus of the present invention. FIG. 4 and FIG.
FIG. 6 is a time chart showing the signal waveforms of the respective parts of the recorder and the reproducer to explain the operation, and FIG. 6 is a diagram showing an example of a graph display obtained from the graph display means. 10: Automobile, 12: Video camera, 14: Recorder, 18: Detributor input side code, 20: Pickup clip, 23: Switch that is turned ON / OFF by operating the brake pedal, 38: First variable resistor, 40 : Amplifier, 42: First one-shot multivibrator, 44: First modulation circuit, 46: First D / A conversion circuit, 47: Voltage division selection circuit, 52: First carrier wave selection circuit, 54: First oscillation circuit, 56: Second oscillation circuit, 60: First engine speed display means, 90: Regenerator, 96: Reference signal generation circuit, 98: Changeover switch, 100: First 5 KHz miss pulse Detector: 102: first 10 KHz miss pulse detector, 104: second D / A conversion circuit, 106: second variable resistor, 108: second engine speed display means, 112: graph display means, 114 : 10KHz low pass filter, 136: resistor, 140: AF amplifier, 142: speaker.

Claims (5)

[Claims] 1. A rotation speed output detecting means for outputting a rotation speed signal having a pulse period corresponding to a rotation speed of an engine of an automobile, and a narrow "L" level pulse for outputting the rotation speed signal for each pulse. Waveform processing means for converting into a modulated signal
Brake pedal operation detecting means for outputting a brake signal in response to operation of the brake pedal, and carrier wave selecting means for selecting either one of first and second frequency signals having different frequencies in accordance with the brake signal are selected. Modulating means for modulating the frequency signal with the modulating signal, and magnetic recording means for recording the modulated signal to be modulated on a magnetic tape,
An operating condition recording / reproducing apparatus comprising: 2. The operating condition recording / reproducing apparatus according to claim 1, wherein the modulation signal is converted into a DC voltage corresponding to a pulse cycle.
A first D / A conversion circuit for A conversion, a voltage division selection circuit for selecting an appropriate voltage division signal of its output, and a first engine rotation speed display means for displaying the rotation speed according to this voltage division signal. And a first variable that divides the voltage of the pulse output from the pickup clip by the waveform processing means, wherein the rotation speed detection means is a pickup clip that sandwiches a cord on the distributor input side of the engine. The voltage dividing selection circuit is formed by a resistor, an amplifier for amplifying the divided voltage signal, and a one-shot multivibrator that is triggered by the amplified output and outputs a modulated signal of a narrow “L” level pulse. Is set according to the number of cylinders of the engine and the first variable resistor is adjusted so that the display of the first rotation speed display means matches the display of the existing engine tachometer of the automobile. Operating condition recording reproducing apparatus characterized by being configured so. 3. The operating state recording / reproducing apparatus according to claim 1, wherein a modulation signal restoring means for restoring the modulated signal from the modulated signal reproduced by the magnetic recording means, and a pulse period of the restored modulation signal are set. Second D to D / A convert to DC voltage
/ A conversion circuit, a brake signal restoring means for restoring the period of the frequency signal selected according to the brake signal from the modulated signal, the restored brake signal and the second
An operating condition recording / reproducing apparatus comprising: a graph display means for displaying the output of the D / A conversion circuit in a graph on the same time axis. 4. An operating condition recording / reproducing apparatus according to claim 3, wherein a reference signal generating means for outputting a reference signal in which a predetermined frequency signal is modulated by a reference pulse, and the reference signal and the reproduced modulated signal are provided. A change-over switch for selectively switching, a second variable resistor for dividing the output of the second D / A conversion circuit, and a second engine speed display means for displaying the engine speed according to the voltage division signal. Before the graph is displayed, the second variable resistor is adjusted while the reference signal is selected by the changeover switch, and the second engine speed display means displays the number of cylinders of the engine. A driving state recording / reproducing apparatus, characterized in that a predetermined number of revolutions is displayed to adjust the magnitude of the output of the second D / A conversion circuit given to the graph display means. 5. An operating state recording / reproducing apparatus according to claim 1, further comprising: an AF amplifier for amplifying the modulated signal reproduced by the magnetic recording means, and a speaker for amplifying the amplified output.
An operating condition recording / reproducing apparatus comprising: