JPH0452655Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention relates to a trigger pulse generation circuit for a waveform recorder, and more specifically, the invention relates to a trigger pulse generation circuit for a waveform recorder. Therefore, in the case of simultaneous measurement, the present invention relates to a trigger pulse generation circuit that generates a pulse to synchronize the timing of the start and end of the measurement.

[Prior Art] Waveform recorders are widely used in industry and research institutions as measuring instruments that can accurately and easily record current waveforms, voltage waveforms, etc. of input signals. Also,
It is also known that there are multifunctional waveform recorders that can simultaneously record input signal waveforms from multiple channels on one recording paper.

However, if it is necessary to record multi-channel input signal waveforms at different paper feed speeds for each channel, a multi-function waveform recorder cannot be used, so multiple single-function waveform recorders can be used in parallel. Each of them will be activated to record waveforms.

In this case, there are multiple time axes, so when analyzing and comparing recorded waveforms, it goes without saying that the paper feed speed of each waveform recorder should be kept constant. Each recording must start at the same time and end at the same time.

Conventional waveform recorders have not always taken into consideration how to operate multiple devices with different paper feed speeds in parallel and simultaneously measure multi-channel signals. It has been difficult to match the start time and end time of waveform recording, or to make the time clear. Therefore, depending on the recorded data, waveform analysis may be hindered.

[Purpose of the invention] This invention was made in view of the above points, and its purpose is to perform waveform conversion on the signal under test input to the waveform recorder to form a rectangular wave signal, and to convert the signal into a rectangular wave signal. By generating a pulse signal synchronized with the rising or falling edge of the waveform and applying it as a trigger signal to other waveform recorders operating in parallel, each waveform recorder starts recording at the same time and records at the same time. An object of the present invention is to provide a trigger pulse generation circuit for a waveform recorder that enables the end of the process.

[Example] Hereinafter, the configuration of this invention will be explained in detail with reference to an example shown in the accompanying drawings.

FIG. 2 shows an example of a waveform recorder equipped with a trigger pulse generation circuit according to this invention.
Referring to the figure, the waveform recorder 1 is provided with a main body measurement circuit 2, a trigger pulse generation circuit 3 consisting of a waveform conversion circuit 3a and a signal control circuit 3b, a switch 4, and the like.

For example, a triangular wave-shaped signal to be measured emitted from a signal source 5 is branched into two paths from an input terminal 6, one of which is applied to the waveform conversion circuit 3a via a switch 4a, and the other signal is It is designed so that it can be directly applied to the signal control circuit 3b.

In the waveform conversion circuit 3a, the applied signal under measurement is subjected to signal processing to form a control pulse signal, which is sent to the signal control circuit 3b. In the signal control circuit 3b, the passage of the signal to be measured sent to the measurement circuit 2 of the main body is controlled to be turned on or off by this control pulse signal. Therefore, by recording the generation timing of the control pulse signal, for example, in a timer, it is possible to easily know the recording start time and end time of the signal under test.

In FIG. 2, a case is shown in which the switch 4 is connected to the contact A side, but if it is switched to the contact B side, it can be operated by an external control pulse signal. That is, the pulse signal is transferred from the trigger signal input terminal 8 to the switch 4b.
It is applied to the contact B of , and also to the signal control circuit 3b in the same manner as above, thereby controlling the passage of the signal under test on and off. In any of the above cases, this control pulse signal is sent out from the output terminal 9 and is used as a trigger signal for other equipment.

FIG. 3 shows an example in which signal waveforms of two channels are measured using two waveform recorders. These two waveform recorders 1A and 1B are configured similarly to the waveform recorder 1 shown in FIG. A measurement signal is added. Furthermore, a signal under measurement in the form of a rectangular wave, for example, is applied from another signal source 10 to the waveform recorder 1B shown in the center. For example, a timer 11 is shown on the right side, but this timer 11 is provided to clarify the start time and end time of waveform recording.
A control pulse signal is applied to the input terminal 12 from the preceding stage waveform recorder 1B via the output terminal 9. In this example, a case is shown in which the waveform recorder 1B operates upon receiving a control pulse signal from the left waveform recorder 1A. Therefore, in the waveform recorder 1A, the internal switch 4 is connected to the contact A side as shown in the figure.
At B, it is connected to the contact B side.

FIG. 1 shows an example of the configuration of this trigger pulse generation circuit 3. As shown in FIG. Referring to the figure, the trigger pulse generation circuit 3 is composed of the waveform conversion circuit 3a and the signal control circuit 3b as described above.
The waveform conversion circuit 3a includes, for example, a comparison circuit 15, an edge selection circuit 19, a photocoupler 22, a gate circuit 25, a pulse generation circuit 28, and the like. Further, the signal control circuit 3b includes, for example, two
Stable multivibrator 35 and buffer amplifier 3
6, an analog switch 37, and the like are provided.

Below, the configuration of each part will be explained in order. The comparator circuit 15 is for forming a rectangular waveform signal from the input signal to be measured, and includes, for example, a buffer amplifier 16, a comparator 17, a reference voltage generation circuit 18, etc. It is equipped with The signal under test inputted from the signal source 5 is applied to the inverting input terminal of the comparator 17 via this buffer amplifier 16. A reference voltage is applied to the non-inverting input terminal of the comparator 17 from the reference voltage generation circuit 18.

The edge selection circuit 19 is a circuit that selects the rising or falling edge of the rectangular waveform signal formed in the comparator circuit 15, and includes, for example, a switch 20 and a buffer amplifier 21. A rectangular wave signal output from the comparator 17 of the comparison circuit 15 is applied to the inverting input terminal or non-inverting input terminal of the buffer amplifier 21 via contact A or B of the switch 20.

The photocoupler 22 is a circuit provided to block external interference voltage induced in the transmission circuit of the signal to be measured, and includes, for example, a photodiode 23 and a phototransistor 24 in this embodiment. The output signal of the buffer amplifier 21 is applied to the anode side of the photodiode 23, and its output voltage is taken out via a photoelectric conversion current flowing between the collector and emitter of the phototransistor 24.

The gate circuit 25 is connected to the next stage pulse generation circuit 28.
This circuit sets the timing of trigger pulse formation in, and includes, for example, a two-input AND circuit 26 and a control circuit 27 that issues a signal to control the timing. This AND circuit 26
The output signal voltage of the phototransistor 24 is applied to one input terminal of the phototransistor 24, and the control signal voltage from the control circuit 27 is applied to the other input terminal. The output signal voltage of the phototransistor 24 is branched and applied to the control circuit 27 . The control circuit 27 monitors the waveform of the applied output signal voltage and sends the control signal voltage to the AND circuit 26 at a predetermined timing. In addition,
The AND circuit 26 may be replaced with, for example, an analog switch.

The pulse generating circuit 28 is a circuit for forming a trigger pulse in synchronization with the control signal from the gate circuit 25, and includes, for example, a first diode 29 connected to the output side of the AND circuit 26, and this circuit. It has a first differentiating circuit 30 connected in series to the diode 29. Further, a second diode 31 is connected to the control signal output side of the control circuit 27, and a second differentiating circuit 32, an inverting circuit 33, etc., which are also connected in series to this diode 31, are connected. There is. The output side of the first differentiation circuit 30 is, for example,
It is connected to the set terminal S of the RS flip-flop circuit 34, and the output side of the inverting circuit 33 is connected to its reset terminal R. The output signal appearing at the output terminal Q of the RS flip-flop circuit 34 is sent to the signal control circuit 3b, and is also sent as a trigger pulse from the output terminal 9 to another waveform recorder (not shown) via the contact A of the switch 4b. It is becoming more and more popular.

In this embodiment, the current directions of the first diode 29 and the second diode 31 are reversed as shown. Therefore, the first differentiating circuit 30 responds to the rising edge of the input signal,
The second differentiating circuit 32 is configured to generate a pulse in response to each falling edge of the input signal.

The signal control circuit 3b is used to turn on and off the input of the signal under test to the main body measurement circuit 2, and as described above, includes, for example, the bistable multivibrator 35, the buffer amplifier 36, and the analog switch 37. It is equipped with such things as A control pulse signal is applied to the analog switch 37 from the output terminal Q of the RS flip-flop circuit 34, thereby turning on/off passage of the signal under test as described above. The time width of this control pulse signal is set by the control signal issued from the control circuit 27, but it does not necessarily have a narrow pulse width, and in the case of long-term measurement, it may have a relatively rectangular waveform. This results in a wide signal waveform.

When using an external trigger pulse,
Turn the switch 4 to the contact B side. As a result, the waveform conversion circuit 3a becomes inactive, and the external trigger pulse applied to the input terminal 8 is transferred to the switch 4b.
The signal is sent from the output terminal 9 to other waveform recorders etc. via the contact B of , and is also input to the bistable multivibrator 35 . A rectangular wave signal voltage appearing at the output terminal Q of the bistable multivibrator 35 is applied to an analog switch 37 via a buffer amplifier 36.

In addition, when measuring the waveform of the signal to be measured without using the trigger pulse generation circuit 3, after switching the switch 4 to the contact B side, turn on the push switch 39 connected to the power supply 38 in the device, for example. All you have to do is turn on the analog switch 37 by operating the above.

Next, the operation of this invention will be explained with reference to FIGS. 4 and 5. Note that, in FIG. 1, the same reference numerals are used at locations where the signal waveforms shown in A to O or O' in FIGS. 4 and 5 above appear.

First, suppose that a triangular waveform signal as shown in FIG. It is applied to a buffer amplifier 16, and its output is input to a comparator 17. In the comparator 17, a reference voltage as shown by the dotted line in B is applied from the reference voltage generation circuit 18, and this reference voltage is compared with the signal input from the buffer amplifier 16, and the output side is A rectangular waveform signal as shown in (c) appears.

Here, assuming that the switch 20 of the edge selection circuit 19 is connected to the contact A side as shown in FIG. 21, and a signal voltage as shown in FIG. 4D appears on the output side. This signal voltage causes the photodiode 23 to emit light, and a photoelectric conversion signal voltage as shown in E of the figure appears on the collector side of the phototransistor 24. This photoelectric conversion signal voltage is input to the AND circuit 26 of the gate circuit 25 and the control circuit 27, but a rectangular waveform signal voltage as shown in F is applied to the AND circuit 26 from the control circuit 27. ing. This signal voltage commands the waveform recorder to start recording, for example, at the time of its rise.
It is assumed that the falling point represents the timing at which a command is issued to inhibit waveform recording.
This rectangular waveform signal voltage may be sent out from the control circuit 27 by manual setting, or may be sent out when the control circuit 27 receives a command signal from a microcomputer or the like (not shown). . In this embodiment, the input waveform of the photoelectric conversion signal shown in E above is monitored in the control circuit 27, and the rise of the rectangular wave control signal voltage is determined by the photoelectric conversion signal shown in F above. This is done by detecting the falling edge of the signal. In this way, when the signal voltages shown in E and F are applied to the AND circuit 26, the signal voltages shown in G appear on the output side and are input to the pulse generation circuit 28.

In the pulse signal generation circuit 28, the signal voltage shown in G above is applied to the first differentiating circuit 30 via the first diode 29, and the pulsed signal voltage shown in G is applied to the output side of the first differentiation circuit 30. appears. This signal voltage is applied to the S terminal of an RS flip-flop circuit 34 provided at the next stage. Further, the control voltage shown in F above is applied to the second differentiating circuit 32 via the second diode 31, and a pulsed signal voltage similarly shown in I appears on the output side. . This signal voltage is inverted in the relative relationship between the H level and the L level by the inverting circuit 33 to become a signal voltage as shown in FIG.
Added to the terminal. In this embodiment, the initial state of the two signals applied to these S terminals is L
level, the output at the Q terminal is set to be at the L level. Therefore,
When the above two signals are applied, the Q terminal has a rectangular shape that rises in response to the first pulse-like signal voltage of the above-mentioned H and falls in response to the pulse-like signal voltage shown in N, as shown in L. A wavy signal voltage is obtained. This signal voltage is applied to the signal control circuit 3
b is applied to the analog switch 37. As a result, the signal under test sent to the main body measurement circuit 2 is
As shown in FIG. 3, the analog switch 37 controls the passage of the signal on and off.

In the above embodiment, when the first pulsed signal voltage shown in H returns to L level, the H level output signal shown in H remains unchanged. Therefore, it does not respond to the second and subsequent H level pulse signal voltages shown in H, and the output from the Q terminal remains unchanged until the reset signal voltage shown in N is input. The signal is held at H level. When comparing the signal waveforms shown in (A) and (C) above, it can be seen that the rising edge of the output signal of the comparator 17 coincides with the time point at which the signal under test is input to the main body measurement circuit 2.

Next, the operation when the switch 20 of the edge selection circuit 19 is connected to the contact B side as shown by the dotted arrow will be briefly described with reference to FIG. In the figure, waveforms A to C are respectively the same as waveforms A to C in FIG. 4, but they are shown again to aid understanding of the explanation.

When the output signal from the comparator 17 is applied to the non-inverting input terminal of the buffer amplifier 21 via the contact B of the switch 20, a rectangular waveform signal voltage shown at D' in FIG. appears. Therefore, for example, on the collector side of the phototransistor 24, as shown in FIG.
A signal voltage appears in which the H level and L level are reversed compared to E in FIG. Due to the signal voltage shown in E' and the signal voltage from the control circuit 27 shown in F', a signal voltage shown in G' appears on the output side of the AND circuit 26. Hereinafter, this signal voltage will be converted into the pulsed signal voltage shown in H' via the first diode 29 and the first differentiating circuit 30, similarly to when the switch 20 is connected to the contact A. It is converted and applied to the S terminal of the RS flip-flop circuit 34. The signal voltage shown in F' above is also converted into a pulsed signal voltage shown in R' through the second diode 31 and the second differentiating circuit 32, and then converted into a pulsed signal voltage shown in N' by the inverting circuit 33. After the signal voltage is made into a signal voltage in which the H level and L level are exchanged, it is applied to the R terminal of the RS flip-flop circuit 34. This results in
The RS flip-flop circuit 34 sends a rectangular waveform signal voltage as shown in line 1 to the analog switch 37. Therefore, main body measurement circuit 2
The signal under measurement input to is shown in O'. Comparing this O' with the signal waveform shown in C above, it can be seen that the falling edge of the output signal of the comparator 17 coincides with the point at which the signal under test is input to the main measurement circuit 2.

When measuring the waveform of a signal under test by receiving a trigger signal from the outside, the trigger signal is applied to the input terminal 8 after switching the switch 4 to the contact B side, as described above. In this case, the initial state of the bistable multivibrator 35 is set so that its Q output is at L level when no trigger signal is applied to the input side. In this way,
For example, if a single trigger pulse is input,
A continuous H-level rectangular wave signal voltage is output from the Q terminal. Further, when a rectangular waveform trigger signal with a relatively wide width is given, it is also possible to output a rectangular waveform signal voltage synchronized with the rise and fall of the trigger signal.

[Effects of the Invention] As described above, according to the trigger pulse generation circuit 3 according to the invention, a rectangular waveform signal voltage is formed in the comparator circuit 15 from the input signal under measurement. An inverted or non-inverted signal of this rectangular waveform signal is extracted by the edge selection circuit 19 and sent to the pulse generation circuit 28 via the gate circuit 25 including the control circuit 27. In the pulse generation circuit 28, the waveform recording start permission and waveform recording prohibition control signals issued from the control circuit 27 cause the pulse generation circuit 28 to rise and fall in response to the rise time of the rectangular waveform signal formed in the comparison circuit 15. A rectangular waveform signal that falls in accordance with the time is formed and is sent as a trigger signal to the signal control circuit 3b that controls on/off the passage of the signal under test applied to the main body measurement circuit 2.

Therefore, with a waveform recorder equipped with this trigger pulse generation circuit, when signals of multiple channels are measured by multiple waveform recorders, even if the paper feeding speed of each device is different, The timing of recording start and recording end can be easily synchronized for all devices. Therefore, it has become possible to perform mutual comparison and analysis of recorded waveforms easily and with high precision.

[Brief explanation of the drawing]

The attached drawings all relate to embodiments of the trigger pulse generation circuit for a waveform recorder according to this invention, and FIG. 1 is a block diagram showing its configuration, and FIG. 2 is a diagram showing a waveform recorder equipped with this trigger pulse generation circuit. A schematic overall configuration diagram, Figure 3 is an explanatory diagram of connections when multiple waveform recorders are operated in parallel, Figures 4 and 5 are
The figure is a signal waveform diagram of each part in the trigger pulse generation circuit. In the figure, 1 is a waveform recorder, 2 is the main body measurement circuit, and 3
3a is a trigger pulse generation circuit, 3a is a waveform conversion circuit,
3b is a signal control circuit, 5 is a signal source to be measured, 15 is a comparison circuit, 17 is a comparator, 18 is a reference voltage generation circuit, 19 is an edge selection circuit, 20 is a switch, 25 is a gate circuit, 26 is an AND circuit, 27
is a control circuit, 28 is a pulse generation circuit, 29, 31
is a diode, 30 and 32 are differentiating circuits, and 34 is a diode.
RS type flip-flop circuit, 37 is an analog switch.

Claims (1)

[Claims for Utility Model Registration] (1) Trigger pulse generation circuit that converts the measured signal input into the waveform recorder into a rectangular wave signal and outputs a trigger signal to turn on and off the recording operation at a predetermined timing. a comparator that compares the signal under test with a reference voltage to form a rectangular wave signal; and an edge selection circuit that includes a switch and selects a rising or falling edge of the rectangular wave signal output from the comparator. and a control circuit that emits a rectangular waveform control signal meaning recording permission and recording prohibition, and a gate circuit that is turned on and off by the control signal from the control circuit, and is inputted via the gate circuit. first and second pulse generation circuits that form two pulse signals having a predetermined time interval from the signal from the edge selection circuit and the control signal; and responsive to one of the two pulse signals. a flip-flop circuit that generates a rectangular waveform signal that rises and falls in response to the other signal; and a switching circuit driven by the output of the flip-flop circuit; A trigger pulse generation circuit for a waveform recorder, characterized in that a signal under measurement input to a main body measurement circuit is controlled to be turned on or off. (2) The rise of the rectangular wave signal with a predetermined time width formed in the flip-flop circuit is synchronized with the rise of the rectangular wave signal output from the edge selection circuit, and the fall thereof is output from the control circuit. Utility model registration claim 1, characterized in that the signal has a time width that is synchronized with the falling edge of a rectangular waveform control signal.
Trigger pulse generation circuit for the waveform recorder described in . (3) The rising edge of the rectangular wave signal with a predetermined time width formed in the flip-flop circuit is synchronized with the falling edge of the rectangular wave signal output from the edge selection circuit, and the falling edge is synchronized with the falling edge of the rectangular wave signal output from the edge selection circuit. Utility model registration claim 1, characterized in that the signal has a time width that is synchronized with the falling edge of a rectangular waveform control signal.
Trigger pulse generation circuit for the waveform recorder described in .