JPH1065207A - Photocoupler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately ascertain actual operating state of a photocoupler without fail. SOLUTION: A photocoupler is equipped with an optically coupling LED 12 and a phototransistor 13, both housed in a casing 11. In this case, an output operation indicating LED 14 which emits light rays when the phototransistor 13 receives light rays is provided to the phototransistor 13. A display window through which light emitted from the output operation indicating LED 14 can be visually observed is provided to the easing 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photocoupler.

[0002]

2. Description of the Related Art Conventionally, an element that couples two electrically insulated electric circuits by light is known as a photocoupler. Such a photocoupler is a combination of two circuits having a potential difference, or a one-way signal passing system,
It is used as such.

In order to confirm whether such a photocoupler is operating or not, conventionally, a light emitting diode (hereinafter referred to as “LED”) is externally attached to an output circuit of the photocoupler. I was However, like this, L
Externally attaching the ED has a problem that it is difficult to reduce the size and weight of the circuit, and also has a problem that it is difficult to simplify and highly integrate the circuit.

Therefore, a photocoupler in which an LED for confirming operation is incorporated has been proposed in Japanese Utility Model Laid-Open No. 2-75755.

FIG. 8 is a diagram showing a photocoupler described in the above publication. In the figure, a photocoupler 1 includes a light coupling LED 3 and a phototransistor 4 in a casing 2. Further, in the casing 2, the display LED 5 is connected in series with the light coupling LED 3 in the casing 2.
The display LED 5 is visible from the outside through a display window opened in the casing 2.

In the photocoupler 1, when an input signal (Vin) is input, the light coupling LED 3 and the display LED 5 emit light. The light from the light coupling LED 3 is received by the phototransistor 4,
An output signal (Vout) is induced on the output side. Further, by visually confirming the light emission of the display LED 5 from the outside through the display window, it can be confirmed that the photocoupler 1 is in the operating state (ON state).

[0007]

However, with the conventional photocoupler 1 described above, even if an abnormality occurs on the output side, such as when the phototransistor 4 is damaged, as long as the input side is normal, There is a problem that the display LED 5 performs a display as if the photocoupler 1 is operating normally. That is, in the above-described conventional photocoupler 1, it is not always possible to accurately confirm the actual operation status.

[0008] The present invention has been made in view of the above circumstances, and not only can the circuit be reduced in size, weight, simplified, and highly integrated, but also the actual operation status can be confirmed. An object of the present invention is to provide a photocoupler that can be reliably performed.

[0009]

According to the first aspect of the present invention, there is provided a photocoupler, wherein a light emitting means for light coupling which emits light when an input signal is applied to the casing, and a light emitted by the light emitting means for light coupling. A light receiving means for receiving light and converting the light into an electric signal, wherein the light receiving means for light coupling has an output operation display for emitting light when light is received by the light receiving means for light coupling. A light emitting means is provided, and the casing is provided with a display window for making light emitted by the output operation display light emitting means visible from the outside. In the photocoupler according to claim 2, in the photocoupler according to claim 1, a set of the light-coupling light-emitting means, the light-coupling light-receiving means, and the output operation display light-emitting means is provided in the casing. Are provided, and the casing is provided with a display window corresponding to each of the output operation display light emitting means. The photocoupler according to claim 3 is the photocoupler according to claim 1 or 2, wherein the light receiving means for optical coupling is provided with an output control terminal for controlling the output sensitivity of the light receiving means for optical coupling. It is characterized by having. The photocoupler according to a fourth aspect is characterized in that, in the photocoupler according to the first or second aspect, the light receiving means for optical coupling is a photoconductive element.

According to the first aspect of the present invention, the light emitting means for light coupling emits light during the operation of the photocoupler. The light from the light emission is received by the light receiving means for optical coupling,
An output signal is induced. When the output signal is induced, the output operation display light emitting unit emits light. The light emitted by the output operation display light emitting means can be visually recognized from the outside through a display window, and the operation state of the photocoupler is confirmed. On the other hand, when the photocoupler is not operating, or when a failure occurs in a circuit component, the output operation display light emitting means does not emit light, and it is confirmed that the photocoupler is not in the operating state. In this case, even if a failure occurs in any of the input-side and output-side circuit components, the output operation display light-emitting means does not emit light, so that the output operation display light-emitting means reliably reflects the actual operation state. Will be. According to the second aspect of the present invention, a set of a plurality of light coupling means for light coupling, a light receiving means for light coupling, and a light emitting means for output operation display is provided in the casing. Therefore, in addition to being able to reliably confirm the actual operation status, further downsizing, weight reduction, simplification, and
High integration is achieved. According to the invention described in claim 3,
The light receiving means for optical coupling is provided with an output control terminal for controlling the output sensitivity of the light receiving means for optical coupling. Therefore, the operation control of the photocoupler is not limited to the input signal,
It can be additionally performed by a control signal to the output control terminal. According to the fourth aspect of the present invention, since the light receiving means for optical coupling is a photoconductive element, the operation control of the photocoupler can be additionally performed not only by the input signal but also by adjusting the sensitivity of the photoconductive element. Is made possible.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment] FIGS. 1 and 2 show a first embodiment of a photocoupler according to the present invention. In the drawings, a photocoupler 10 comprises a casing 11, an optical coupling LED (optical coupling LED). The light emitting device includes a light emitting means 12, a phototransistor (light receiving means for optical coupling) 13, an output operation display LED (light emitting means for output operation display) 14, and the like.

The casing 11 has an optical coupling LE inside.
D12, phototransistor 13, output operation display LE
D14, and a four-terminal element having terminals 15, 16, 17, and 18. In addition, a display window 11a (shown in FIG. 2) is formed in the casing 11 so that light emitted by the output operation display LED 14 can be visually recognized from the outside.

The light coupling LED 12 is connected between a positive (+) input terminal 15 and a negative (−) input terminal 16 in the casing 11. Then, when an input signal is applied, light is emitted inside the casing.

The phototransistor 13 includes a casing 1
In FIG. 1, it is connected between a positive (+) output terminal 17 and a negative (−) output terminal 18. And
When receiving light emitted by the light-coupling LED 12, an electric signal (output signal) is induced.

The output operation display LED 14 is connected to the phototransistor 13 in the casing 11 in series in the illustrated direction. And L for optical coupling
When light is received by the ED 12, light is emitted. As described above, this light emission is visible from the outside through the display window 11a formed in the casing 11.

Next, the photocoupler 10 having the above configuration
Will be described.

When the photocoupler 10 is operating (ON), the light coupling LED 12 emits light. An output signal is induced by the phototransistor 13 receiving the light due to the light emission. Therefore, the coupling of the input side circuit and the output side circuit is achieved. At the same time, when an output signal is induced, the output operation display LED 14 emits light. The light emitted by the output operation display LED 14 can be visually recognized from the outside via the display window 11a, and the operation state of the photocoupler 10 is confirmed.

On the other hand, when the photocoupler is not operating (OFF
Time), or if a circuit component fails,
The output operation display LED 14 does not emit light, and it is confirmed that the photocoupler 10 is not operating.
In this case, even if a failure occurs in any of the circuit components on the input side and the output side, the output operation display LED 14 does not emit light, so that the output operation display LED 14 reliably reflects the actual operation state. Become.

As described above, according to the photocoupler 10, there is an effect that the actual operation status can be surely confirmed. In this case, the output operation display LED 14
It is obvious that the provision of the inside of the casing 11 makes it possible to achieve a reduction in size, weight, simplification, and high integration of the circuit. Also, since the number of parts can be minimized,
Maintainability can be improved.

[Second Embodiment] FIG. 3 shows a photocoupler according to a second embodiment of the present invention. This embodiment is different from the first embodiment in that the light coupling LED provided in the package 11 is provided.
The number of pairs of (light coupling means for optical coupling) 12, the phototransistor (light receiving means for optical coupling) 13, and the LED for output operation display (light emitting means for output operation display) is four, and the number of display windows 11a is There are only four elements and 16 terminal elements, and the other elements have the same configuration. In the present embodiment, the first
The same members as those of the embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In the photocoupler 20 of this embodiment, four sets of the light coupling LED 12, the phototransistor 13, and the output operation display LED 14 are provided.
The circuit configuration in each set is the same as in the first embodiment,
Each set is electrically and optically insulated (or isolated) in the casing 11. Correspondingly, the number of the display windows 11a is four, and the terminals are 16 terminals.

In this embodiment, the light coupling LED 1
2, phototransistor 13, output operation display LED1
Although the number of sets of 4 is four, the present invention is not limited to this, and may be any number.

In the present embodiment, the same functions and effects as those of the first embodiment can be obtained. In addition, by providing a plurality of sets of the light coupling LED 12, the phototransistor 13, and the output operation display LED 14 in the casing 11, further downsizing, weight reduction, simplification, and high integration of the circuit are achieved. Can be achieved.

Third Embodiment FIG. 4 shows a third embodiment of the photocoupler according to the present invention. This embodiment differs from the first embodiment in that a phototransistor (light receiving means for optical coupling) 13 has an output control terminal 3 for controlling the output sensitivity of the phototransistor 13.
1 is provided, and the other configuration is the same. In the present embodiment, the same members as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, the phototransistor 13 has an output control terminal 31. A switch 32 is connected to the output control terminal 31, and the switch 32 can select a + V or -V line voltage by switching.

In this embodiment, the photocoupler 30
Can be additionally controlled not only by the input signal but also by the control signal to the output control terminal 31 by switching the switch 32. That is, in addition to controlling the operation of the photocoupler 30 in addition to the normal input signal, the photocoupler 30 can be forcibly turned on or off by switching the switch 32.

In the present embodiment, the same functions and effects as those of the first embodiment can be obtained. In addition, the control signal to the output control terminal 31 causes the photocoupler 30
Can be additionally performed, and the circuit can be further simplified. In addition, operability can be improved.

The method of applying a control signal to the output control terminal 31 is not limited to the method shown in FIG. 4, but may be a method shown in FIG. That is, in FIG. 5, a control signal is applied to the output control terminal 31 via the variable resistor 33. In this way, not only the ON / OFF control of the phototransistor 13 but also the sensitivity of the phototransistor 13 can be adjusted more precisely.

The method of applying the control signal to the output control terminal 31 is not limited to the above method, but may be any other method.

[Fourth Embodiment] FIG. 6 shows a fourth embodiment of the photocoupler of the present invention. This embodiment is different from the first embodiment only in that a photoconductive element 41 is used instead of the phototransistor 13 as the light receiving means for optical coupling. Have been. In the present embodiment, the same members as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, a photoconductive element 41 is used as a light receiving means for optical coupling. Therefore, the operation control of the photocoupler 40 can be additionally performed not only by the input signal but also by adjusting the sensitivity of the resistance of the photoconductive element 41. That is, in addition to controlling the operation of the photocoupler 40 to the normal input signal, the photoconductive element 4
The operating condition of the photocoupler 40 can be adjusted by adjusting the sensitivity of the resistor 1.

In the present embodiment, the same functions and effects as those of the first embodiment can be obtained. In addition, by adjusting the sensitivity of the photoconductive element 41, the operation of the photocoupler 40 can be additionally controlled, and the circuit can be further simplified. In addition, operability can be improved.

[Fifth Embodiment] FIG. 7 shows a fifth embodiment of the photocoupler of the present invention. This embodiment differs from the first embodiment only in that an output control circuit 51 is provided on the output side, and the other configuration is the same. In the present embodiment, the same members as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, an output control circuit 51 is provided on the output side. This embodiment is suitable when the terminals 17 and 18 have a large difference in current level from the input side, such as a large current control circuit or a very small current control circuit. In this case, the output control circuit 51 includes:
It is preferable to provide an output control terminal 52 for forcibly turning on / off the photocoupler 50.

In the present embodiment, the same functions and effects as those of the first embodiment can be obtained. In addition, the photocoupler 50 can be used for controlling a large current control circuit or a very small current control circuit.

[0037]

According to the photocoupler of the present invention, the following effects can be obtained. According to the photocoupler of the first aspect,
The light receiving means for optical coupling is provided with a light emitting means for output operation display which emits light when light is received by the light receiving means for optical coupling, and the casing is provided with light generated by the light emitting means for output operation display. Since the display window is provided so that it can be visually recognized from the outside, it is possible to surely confirm the actual operation state. In this case, by providing the output operation display light emitting means in the casing, it is apparent that the circuit can be reduced in size, weight, simplified, and highly integrated. Further, maintainability can be improved. According to the photocoupler according to the second aspect, since a set of a plurality of light-emitting means for optical coupling, a light-receiving means for optical coupling, and a light-emitting means for output operation display is provided in the casing, an actual operation state is provided. Can be surely performed, and further downsizing, weight reduction, simplification, and high integration of the circuit can be achieved. According to the photocoupler of claim 3, the light receiving means for optical coupling is provided with an output control terminal for controlling the output sensitivity of the light receiving means for optical coupling. The operation control of the photocoupler can be additionally performed, and the circuit can be further simplified. According to the photocoupler of claim 4, since the light receiving means for photocoupling is a photoconductive element, the operation control of the photocoupler can be additionally performed by adjusting the sensitivity of the photoconductive element, The circuit can be further simplified.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a first embodiment of a photocoupler according to the present invention.

FIG. 2 is a perspective view of the photocoupler shown in FIG.

FIG. 3 is a perspective view showing a second embodiment of the photocoupler of the present invention.

FIG. 4 is a circuit diagram showing a third embodiment of the photocoupler according to the present invention.

FIG. 5 is a circuit diagram showing a modification of the photocoupler shown in FIG.

FIG. 6 is a circuit diagram showing a fourth embodiment of the photocoupler of the present invention.

FIG. 7 is a circuit diagram showing a fifth embodiment of the photocoupler of the present invention.

FIG. 8 is a circuit diagram illustrating an example of a conventional photocoupler.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Photocoupler 11 Casing 11a Display window 12 LED for light coupling (light emitting means for light coupling) 13 Phototransistor (light receiving means for light coupling) 14 LED for output operation display (light emitting means for output operation display) 20 photocoupler 30 photocoupler 31 output control terminal 40 photocoupler 41 photoconductive element 50 photocoupler

Claims (4)

[Claims] 1. An optical coupling light emitting means for emitting light when an input signal is applied in a casing, and a light receiving means for optical coupling for receiving light emitted by the light emission of the optical coupling light and converting the light into an electric signal. Wherein the light receiving means for optical coupling is provided with a light emitting means for displaying an output operation which emits light when light is received by the light receiving means for optical coupling; A photocoupler provided with a display window for allowing light emitted by the display light-emitting means to be visually recognized from outside. 2. The photocoupler according to claim 1, wherein a plurality of sets of the light coupling means, the light coupling light receiving means, and the output operation display light emitting means are provided in the casing. A photocoupler, wherein the casing is provided with a display window corresponding to each of the output operation display light emitting means. 3. The photocoupler according to claim 1, wherein said light receiving means for optical coupling is provided with an output control terminal for controlling output sensitivity of said light receiving means for optical coupling. Photo coupler. 4. The photocoupler according to claim 1, wherein said light receiving means for optical coupling is a photoconductive element.