JPH0435921Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] This invention relates to a display device that displays the status of power equipment such as a motor.

[Background technology]

When operating a motor, etc., a display device provided separately from the control device generally displays operation, stop, and failure indications so that the state of the motor can be monitored. In order to cause the display device to display the above three types of displays, it is necessary to send a signal indicating the state of the motor from the control device to the display device. Conventionally, as a signal sent from a control device to a display device,
Three types of states are set: continuous high level state, continuous low level state, and periodic level change state, and the display signal state (continuous high level, continuous On the other hand, the display device determines the state of the display signal sent from the control device, and changes the operation indicator, stop indicator, and fault indicator according to the determination result. It was supposed to turn on one of the lights.

Such conventional display devices simply light up not only the operation indicator and the stop indicator, but also the failure indicator, which makes it difficult to tell that there is a failure and delays response to the failure. It was hot.

Therefore, we added a flicker circuit to the fault indicator,
Some devices display a failure using a flashing display.

However, when adding a flicker circuit to a fault indicator in this way, when multiple circuits are incorporated into one control panel, the number of flicker circuits required is equal to the number of fault indicators, which increases component costs and increases power consumption. The problem is that there are too many. Another problem is that when two or more failure indicators operate at the same time, they each blink at different timings, which is unnatural.

[Purpose of invention]

The object of this invention is to provide a display device that can display a failure as a blinking display without incorporating a flicker circuit, and can also reduce costs and power consumption.

[Disclosure of invention]

The display device of this invention, as shown in FIG.
A display device to which an input signal is applied which causes a continuous one level state in response to an operating state, a continuous other level state in response to a stopped state, and a periodic level change state in response to a fault state. hand,
A first output signal of a constant level is generated from the first output terminal TA ₁ when the input signal is continuously at one level, and a second output signal is generated when the input signal is continuously at another level. A second output signal of a constant level is generated from the output terminal TA ₂ of the circuit, and a third output signal of a constant level is generated from the third output terminal TA ₃ when the input signal is in a periodic level change state. a signal discriminating circuit 2; an AND circuit 3 which takes a logical product of the third output signal of the signal discriminating circuit 2 and the input signal; and a first AND circuit of the signal discriminating circuit 2;
and a run indicator 4 and a stop indicator 5 that respond to the second output signal, respectively, and the AND circuit 3.
The present invention is characterized in that it is configured to include a failure indicator 6 that responds to the output signal of.

Note that 1 is an input interface circuit, and 7 is an alarm buzzer.

A first embodiment of this invention will be explained based on FIGS. 2 to 4. This display device is in a continuous high level state in response to an operating state, a continuous low level state in response to a stopped state, and a periodic level change state in response to a fault state.
₁ is a display device to which an input signal as shown in FIG. generates an output signal, and generates a second output signal of a constant level from a second output terminal TA ₂ when the input signal is in a continuous low level state, and the input signal is in a periodic level change state; Sometimes the third
a signal discriminating circuit 2 which generates a third output signal of a constant level from an output terminal TA 3 of the signal discriminating circuit ₂ ; an AND circuit 3 which calculates the logical product of the third output signal of the signal discriminating circuit 2 and the input signal; The first of the discrimination circuit 2
and a run indicator 4 and a stop indicator 5 that respond to the second output signal, respectively, and the AND circuit 3.
The configuration includes a failure indicator 6 and an alarm buzzer 7 that respond to the output signal of the alarm.

To explain in more detail, the input interface circuit 1 includes a transistor Tr ₁ , an inverter IN ₁ ,
Consists of resistors R ₁ to R ₄ and capacitor C ₁ ,
This is to prevent input signal chattering, etc., and the output waveform is similar to that shown in FIG. 4A.

Furthermore, the monostable multivibrator 2A constituting the signal discrimination circuit 2 is a retriggerable type, and is composed of a main body block IC ₁ , an external resistor _R5 , _and a capacitor _C2 . ₂ determines the metastable period. The output Q of this monostable multivibrator 2A is at a high level for a certain period of time immediately after the start of operation and during a failure period, as shown in FIG. 4B. The reason why the level remains high during the failure period is that the monostable multivibrator 2A is triggered and enters a metastable state, but is retriggered before reaching a stable state, and the period of the input signal is equal to the quasi-stable state of the monostable multivibrator 2A. It needs to be shorter than the stable period. FIG. 4C shows a waveform diagram of the inverted output.

Integrating circuit 2B is monostable multivibrator 2
It integrates the output voltage of A, and consists of a resistor R ₆ , a capacitor C ₃ , a resistor R ₇ for instantaneous discharge, and a diode D ₁ , and its output is shown in Figure 4 D.
During the operation period, the pulse width in Figure 4B is narrow, so when there is only one pulse, the threshold value
If V _TH is not exceeded and a failure occurs and the input signal enters a periodic level change state and the pulse width of FIG. 4B becomes longer, the output voltage will exceed the threshold V _TH .

When the operation starts, the input signal becomes high level,
Therefore, the output of the input interface circuit 1 also becomes high level. Monostable multivibrator 2A
is triggered by the rising edge of the input signal, and the output Q is the fourth
The signal becomes high level as shown in FIG. 4B, and the inverted output becomes low level as shown in FIG. 4C. Then, after the metastable period passes, the output Q becomes a low level and the inverted output becomes a high level, resulting in an AND circuit.
The output of AN ₁ becomes high level as shown in Fig. 4E, turning on transistor Tr ₂ and lighting red light emitting diode LED ₁ to display operation. At this time, since the output of the integrating circuit 2B does not exceed the threshold value _VTH , the output of the AND circuit 3 remains at a low level as shown in FIG. 4F. Also, the AND circuit
Since the output of AN ₁ is at high level and the output of inverter IN ₃ is at low level as shown in FIG. 4H, the output of AND circuit AN ₂ is at low level as shown in FIG. 4J.

When the operation is stopped, the input signal becomes low level,
Therefore, the output of the input interface circuit 1 also becomes low level, and the output of the integrating circuit 2B (the fourth
(D) does not exceed the threshold value V _TH , both the outputs of inverters IN ₂ and IN ₃ (G, H in FIG. 4) become high level, and the output of AND circuit AN ₂ (I in FIG. 4) goes high. level, turning on transistor Tr ₃ and lighting green light emitting diode LED ₂ to indicate a stop. At this time, the AND circuit AN ₁ ,
The outputs of No. 3 (E and F in FIG. 4) are each at a low level.

When a fault occurs during operation, the input signal enters a periodic level change state, the monostable multivibrator 2A is retriggered, the output Q maintains a high level state, and the output of the integrating circuit 2B reaches the threshold value V _TH
It will exceed. As a result, a high level input and a periodic level change input are applied to the AND circuit 3, and the output of the AND circuit 3 (FIG. 4F) is in a periodic level change state, causing the transistor Tr ₄ to be turned on and off. The yellow light emitting diode LED ₃ flashes and the alarm buzzer 7 sounds intermittently to notify the failure. At this time, the inverted output of monostable multivibrator 2A (Fig. 4C)
Since is at a low level, the output of the AND circuit AN ₁ is at a low level, and since the output of the integrating circuit 2B is at a high level, the output of the AND circuit AN ₂ is at a low level.

As described above, in this embodiment, the output of the integrating circuit 2B and the output of the input interface circuit 1 are ANDed, and the light emitting diode LED ₃ and the alarm buzzer 7 are turned on and off by this AND output, so that the flickering is prevented. There is no need to add a circuit, and it is possible to achieve cost reduction and reduce power consumption. In addition, since the blinking of the light emitting diode LED ₃ is synchronized with the flickering operation of the input signal, even if multiple circuits are installed in one control panel, each one will blink at the same timing, and even if multiple fault indications are displayed at the same time. No unnaturalness occurs.

A second embodiment of this invention will be explained based on FIG. This display device is similar to the first embodiment except that the alarm buzzer 7 is operated continuously. Note that AN ₃ is an AND circuit, and Tr ₅ is a transistor, which has only simple amplification and switching functions.

The effects of this embodiment are similar to those of the first embodiment.

In each of the above embodiments, the continuous high level state of the input signal corresponds to the operating state, and the continuous low level state of the input signal corresponds to the stopped state, but this may be made to correspond in the opposite manner.

[Effect of idea]

According to the display device of this invention, it is possible to display a failure as a blinking display without adding a flicker circuit, thereby preventing delays in dealing with failures, and achieving cost reduction and lower power consumption. I can do it.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the configuration of this invention, Fig. 2 is a block diagram of the first embodiment of this invention, Fig. 3 is its detailed circuit diagram, Fig. 4 is a timing diagram of each part, and Fig. 5 is a block diagram showing the configuration of this invention. The figure is a block diagram of a second embodiment of this invention. 2... Signal discrimination circuit, 3... AND circuit, 4...
...Operation indicator, 5...Stop indicator, 6...Failure indicator.

Claims (1)

[Scope of utility model registration request] A display device to which an input signal is applied which causes a continuous one level state in response to an operating state, a continuous other level state in response to a stopped state, and a periodic level change state in response to a fault state. hand,
A first output signal of a constant level is generated from a first output terminal when the input signal is in a continuous one level state, and a second output signal is generated when the input signal is in a continuous other level state. a signal discrimination circuit that generates a second output signal of a constant level from a terminal, and generates a third output signal of a constant level from a third output terminal when the input signal is in a periodic level change state; an AND circuit that takes a logical product of the third output signal of the signal discrimination circuit and the input signal; an operation indicator and a stop indicator that respond to the first and second output signals of the signal discrimination circuit, respectively; A display device comprising a fault indicator that responds to an output signal of an AND circuit.