JPH0641234U - Monostable multivibrator - Google Patents

Abstract

(57) [Summary] [Structure] A photo coupler in which a light emitting element for converting an electric signal into an optical signal and a light receiving element for converting an optical signal into an electric signal are kept in an electrically insulated state and combined into one system. The two light receiving elements of 1 are arranged in parallel at the input part of the monostable multivibrator. [Effect] Both the PNP sensor and the NPN sensor can be used, and versatility can be expanded.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a monostable multivibrator whose operation is stable when either one of two electronic devices is turned on.

[0002]

[Prior art]

 Conventionally, a processing facility for processing a workpiece operates independently for each process, and a person performs the connection of the processes, for example, moving the workpiece and attaching the workpiece to the facility. However, in recent years, automation of processing equipment has been promoted for the purpose of shortening processing time and reducing personnel. Control of such automated processing equipment is often configured by a combination of a sensor 131 and a sequencer 132 as shown in FIG. For example, when the work passes in front of the sensor 131, the sensor 131 turns on the internal switch, and the sequencer 132 reads the ON state of the internal switch, which causes the sequencer 132 to output an instruction signal to the inspection station and I was conducting an inspection. Such control of the sequencer 132 is not limited to the inspection station, but various controls such as attachment / detachment of workpieces and lighting of lamps can be performed.

In the above control, when the sequencer 132 reads the ON state of the internal switch of the sensor 131, the sequencer 132 instructs the next operation, but the sequencer 132 reads in time division, for example, once every 10 ms. Since the reading is performed in proportion, when the speed of the work passing in front of the sensor 131 becomes high, the ON state h of the internal switch of the sensor 131 becomes shorter than 10 ms as shown in FIG. Moreover, the ON state of the internal switch of the sensor 131 ends, and the sequencer 132 cannot read that the internal switch of the sensor 131 is turned ON. If the work passes through without being read by the sequencer 132 in this way, the processing in the subsequent process is not performed, and defective products or equipment abnormalities occur, and the automated equipment stops. Problems such as storage will occur.

Therefore, as described above, in order to prevent the sequencer 132 from being unable to read that the internal switch of the sensor 131 is turned on, as shown in FIG. 1, a general single unit is provided between the sensor 131 and the sequencer 132. It is conceivable to add the stable multivibrator 101. As shown in the circuit diagram of FIG. 7, the monostable multivibrator 101 includes a light receiving element 108 combined with the light emitting element 107 of the sensor 131, two transistors 113 and 123, capacitors 116 and 121, and a plurality of resistors 115 and 5. As shown in FIG. 2, the monostable multivibrator 101 is composed of 118, 120, 122 and a variable resistor 119. As shown in FIG. 2, the ON state h of the internal switch of the sensor 131 is a pulse of a certain length (10 ms or more) It is converted into the width i and output. Therefore, no matter how fast the work passes in front of the sensor 131, the monostable multivibrator 101 detects the ON state of the internal switch of the sensor 131 and outputs a signal i longer than the s interval read by the sequencer 132 to the sequencer 132. Since the force is applied, the sequencer 132 does not miss the passage of the work.

[0005]

[Problems to be solved by the device]

 There are two types of sensors 131 connected to the monostable multivibrator 101, a PNP sensor and an NPN sensor, and these two types of sensors 131 are selectively used depending on the direction in which the current of the monostable multivibrator 101 flows. Only the PNP sensor can be used in the circuit as shown in FIG. 7, and the NPN sensor cannot be used. On the contrary, in the circuit using the NPN sensor, the PNP sensor cannot be used, and there is a problem that the versatility is low in this respect.

Therefore, an object of the present invention is to solve the above problems and provide a monostable multivibrator that can be used with both PNP and NPN sensors.

[0007]

[Means for Solving the Problems]

 The structure of the present invention is as follows.

A light receiving element of a photo coupler, in which a light emitting element for converting an electric signal into an optical signal and a light receiving element for converting an optical signal into an electric signal are kept in an electrically insulated state and combined into one system, Two monostable multivibrators were placed in parallel at the input.

[0009]

【Example】

 An embodiment of the present invention will be described with reference to FIGS.

FIG. 1 shows a configuration in which the monostable multivibrator 1 of the present invention is used. There is a sensor 31 that turns on an internal switch while a work is passing through and an on state of an internal switch of the sensor 31. It is composed of a monostable multivibrator 1 which converts and outputs the signal of a constant length, and a sequencer 32 which detects the signal output by the monostable multivibrator 1 and instructs the subsequent processing. Here, the length of the signal converted by the monostable multivibrator 1 will be described with reference to FIG. 2. When the work passes in front of the sensor 31, the internal switch of the sensor 31 is turned on, but the sequencer 32 always outputs the signal. In order to detect h, the monostable multivibrator 1 converts the signal i longer than the reading s interval of the sequencer 32 and outputs it to the sequencer 32. Thereby, the sequencer 32 does not miss the passage of the work.

Next, the sensor 31, the monostable multivibrator 1, and their connections will be described based on the circuit diagram of FIG.

In the figure, the monostable multivibrator 1 is a collector-coupled type composed of two transistors 13 and 23, and as described above, the pulse width (output time) can be adjusted at the output terminal 25. Reference numeral 24 is a positive power supply terminal, 21 and 16 are capacitors, 15, 18, 20, and 22 are resistors, and 19 is a variable resistor. Among them, the capacitor 21 and the variable resistor 19 are a time constant capacitor and a time constant resistor that determine the pulse width at the output terminal 25.

The sensor 31 uses a PNP sensor, 2 is a positive power supply terminal, and 3 is a ground. The sensor 31 and the monostable multivibrator 1 are connected by the set photocoupler 6 of the photocouplers 6 and 9 arranged in parallel. The photo couplers 6 and 9 are a combination of light emitting elements 7 and 10 for converting an electric signal into an optical signal and light receiving elements 8 and 11 for converting an optical signal into an electric signal in one system. A light emitting diode is generally used as 10, and a phototransistor is often used as the light receiving elements 8 and 11. However, the light emitting elements 7 and 10 and the light receiving elements 8 and 11 are not limited to the above types.

Next, operations of the sensor 31, the monostable multivibrator 1, and the sequencer 32 described above will be described.

First, the switch is turned on to supply a voltage to the sensor 31, the monostable multivibrator 1, and the sequencer 32. At this time, the monostable multivibrator 1 stands still in a stable state in which one transistor 13 is turned off and the other transistor 23 is turned on. When a workpiece passes in front of the sensor 31 in this state, the internal switch of the sensor 31 is turned on, and the light emitting element 7 of the photo coupler 6 converts the electric signal into an optical signal at the time when the ON state is detected. , To the light receiving element 8. Then, the light receiving element 8 that receives the optical signal converts the optical signal into an electric signal and outputs the electric signal into the monostable multivibrator 1. When an electric signal is applied to the transistor 13, the on / off states of the transistors 13 and 23 are reversed and an output pulse is generated at the output terminal 25. This reversal continues for a period of time determined by the capacitance value of the time constant capacitor 21 and the resistance value of the time constant resistor 19 (T = 0.7 × time constant capacitor capacitance value × time constant resistor resistance value). , After that, it becomes stable. After that, the above operation is repeated each time an electric signal is received from the sensor 31. The time T is the pulse width of the output pulse generated at the output terminal 25. Upon receiving this pulse, the sequencer 32 instructs the next operation. At this time, the pulse width is set to be longer than the reading time of the sequencer 32 by the monostable multivibrator 1. Therefore, if a pulse is generated during the reading of the sequencer 32, the occurrence of the pulse will not be overlooked.

Although the PNP sensor is used in the above description, an example using the NPN sensor is shown in FIG.

The NPN sensor is connected to the one photo coupler 6 connected to the PNP sensor and the other photo coupler 9 arranged in parallel. On the other hand, when the photo coupler 9 and the NPN sensor are connected, the PNP sensor is not connected and the photo coupler 6 does not operate. Similar to the case where the PNP sensor is connected, the monostable multivibrator 1 and the sequencer 32 perform the same operation even when the NPN sensor is connected.

Therefore, when the PNP sensor is used, it is connected to one photo coupler 6 of the monostable multivibrator 1, and when the NPN sensor is used, it is connected to the other photocoupler 9 of the monostable multivibrator 1. Each sensor can be used.

[0019]

[Effect of device]

 As described above, according to the present invention, a light emitting element for converting an electric signal into an optical signal and a light receiving element for converting an optical signal into an electric signal are kept in an electrically insulated state and combined in one system. Since the two light receiving elements of the coupler are arranged in parallel to the input part of the monostable multivibrator, both the PNP sensor and the NPN sensor can be used and the versatility can be expanded.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an apparatus using a monostable multivibrator.

FIG. 2 is a graph showing a time chart by an apparatus using a monostable multivibrator.

FIG. 3 is a circuit diagram showing a device using a monostable multivibrator and a PNP sensor of the present invention.

FIG. 4 is a circuit diagram showing an apparatus using a monostable multivibrator and an NPN sensor of the present invention.

FIG. 5 is a configuration diagram showing a conventional device that does not use a monostable multivibrator.

FIG. 6 is a graph showing a time chart of a conventional device that does not use a monostable multivibrator.

FIG. 7 is a circuit diagram showing a conventional device using a monostable multivibrator.

[Explanation of symbols]

 1 Monostable multivibrator 6,9 Photo coupler 7,10 Light emitting element 8,11 Light receiving element

Claims (1)

[Scope of utility model registration request] 1. A light emitting element (7), (10) for converting an electric signal into an optical signal and a light receiving element (8), (11) for converting an optical signal into an electric signal are kept in an electrically insulated state. Two photo detectors (8) and (11) of photo couplers (6) and (9) combined in one system are arranged in parallel to the input part of the monostable multivibrator (1). A monostable multivibrator.