JP3823583B2 - Programmable controller and printed wiring board - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention includes a light receiving transistor that is driven by a power source and responds to a signal processed by an internal circuit, and an output transistor that turns on / off a power source to a load by a signal output from the light receiving transistor. The present invention relates to a programmable controller incorporating a printed wiring board.
[0002]
[Prior art]
In recent years, programmable controllers have been widely used as one that can flexibly cope with changes and additions of various specifications by changing a sequence program as one of sequence control devices. A device connected to the input terminal of the programmable controller is called an input device. These input devices include various switches such as proximity switches and limit switches, various sensors such as pressure sensors, temperature sensors, and humidity sensors, and others. A device connected to the output terminal of the programmable controller is called an output device. These output devices include various relays such as a contact relay and a non-contact relay, a switch, a solenoid of a solenoid valve, etc., or a programmable controller connected to the programmable controller.
[0003]
Such a programmable controller is mainly composed of one or a plurality of input circuits for taking in signals from various input devices and a microprocessor unit incorporating a microcomputer, a memory and the like, and is an internal circuit for processing signals by sequence control. And one or a plurality of output circuits for outputting signals from the internal circuit to a plurality of output devices as loads as a result of execution of the sequence program. There are various output circuit methods in such a programmable controller, and there is a method called a transistor output circuit in which the output transistor is an open collector method, and this transistor output circuit also uses a method using an npn type output transistor. There is a method using a pnp type output transistor.
[0004]
FIG. 7 is a principal circuit diagram showing a programmable controller having a transistor output circuit using an npn type output transistor and a load and a power source connected to the programmable controller. FIG. 8 is a transistor output circuit using a pnp type output transistor. It is a principal part circuit diagram which shows the programmable controller provided with, the load connected to it, and a power supply. A conventional transistor output circuit in the programmable controller will be described with reference to these drawings. The programmable controller has the number of output terminals corresponding to the number of output devices connected to it (the number of output points). However, in FIGS. For this purpose, only one transistor output circuit is shown.
[0005]
First, a programmable controller provided with a transistor output circuit using the npn type output transistor shown in FIG. 7 will be described. 2 is a programmable controller, 4 is an output device as a load, and 6 is a power supply for an output device as a load. Reference numeral 8 denotes an internal circuit of the programmable controller 2 and reference numeral 10 denotes a transistor output circuit. The programmable controller 2 also has a power supply terminal 12 to which the power supply 6 is connected, an output terminal (OUT) 14 to which the output device 4 is connected, and a common terminal (COM) 16.
[0006]
The transistor output circuit 10 is connected to the light emitting diode 18 that emits light in response to the input of the signal from the internal circuit 8 and the power supply terminal 12 in order to output the signal from the internal circuit 8 to the output terminal 14. The light receiving transistor 20 responds to the light emission of the light emitting diode 18, the resistor 22, and the npn type output transistor 26. Here, R22 is a resistor for limiting the base current of the output transistor 26. In this case, the light-emitting diode 18 and the light-receiving transistor 20 are photocouplers, and the programmable controller 2 having such a photocoupler is also called a photocoupler insulation type, and the programmable controller 2 side and the output device 4 side are electrically connected. By electrically isolating the programmable controller 2 and the output device 4, even if the power supply system is different, the user does not need to worry about the wraparound of electricity due to the potential difference generated by the different power supply system. Connection when connecting the output device 4 to the controller 2 can be easily performed without special consideration.
[0007]
In such a programmable controller 2, for example, when a sensor is detected as an input device (not shown) and a signal corresponding thereto is input to the programmable controller 2, the internal circuit 8 supplies the light-emitting diode 18 to the light-emitting diode 18 according to a predetermined sequence. Output a signal. As a result, the light emitting diode 18 emits light, and the light receiving transistor 20 disposed opposite thereto receives the emitted light and conducts. When the light receiving transistor 20 is turned on, the base current is supplied to the base of the output transistor 26, and as a result, the output transistor 26 is turned on. When the output transistor 26 is turned on, the output device 4 such as a relay or an electric motor is supplied with the power supply 6 and can perform a required operation corresponding to the detection of the sensor.
[0008]
Next, a programmable controller including a transistor output circuit using a pnp type output transistor will be described with reference to FIG. In FIG. 8, parts corresponding to those in FIG. In the programmable controller shown in FIG. 8, the output transistor 26 a is a pnp type, its emitter is connected to the common terminal 16, and its base is connected to the light receiving transistor 20. The rest is the same as the transistor output circuit shown in FIG.
[0009]
[Problems to be solved by the invention]
In such a programmable controller, since the connection of the circuit is different in any transistor output circuit, in order to mount the components constituting both transistor output circuits on the same printed wiring board, the component mounting area is the output of each transistor. It is necessary for the circuit, and the mounting area of the printed circuit board is required to be double the mounting area of the printed circuit board when mounting the components of either transistor output circuit is required. In addition, when one transistor output circuit is used on the same printed circuit board, the other transistor output circuit is unnecessary, so unnecessary transistor output circuit components are wasted. Uneconomical and expensive That.
[0010]
In addition, when each transistor output circuit is mounted on a separate printed circuit board, it is necessary to prepare for manufacturing two printed circuit boards on which a large number of components including at least the internal circuit are mounted. In addition to being disadvantageous in terms of manufacturing cost of the printed wiring board, if a printed wiring board having one of the transistor output circuits is used, the printed wiring board having the other transistor output circuit is not used. Similarly to the above, parts are wasted and printed wiring boards are wasted, which is very uneconomical and expensive.
[0011]
[Means for Solving the Problems]
In the programmable controller of the present invention, a light receiving transistor driven by a power source and responding to a signal processed by an internal circuit, and an output transistor for turning on / off a power source to a load by a signal output from the light receiving transistor, In the programmable controller incorporating the printed wiring board mounted with the printed circuit board, the printed wiring board includes a first printed wiring for switching a connection path of the power source to the light receiving transistor, and a connection of the base of the output transistor to the light receiving transistor. A second printed wiring for switching a path, wherein the first printed wiring is a printed wiring portion formed between a collector of the light receiving transistor and the power source, an emitter of the light receiving transistor, and the power source. Between It is intended to include a formed printed wiring portion, wherein depending on the type of the output transistor to be mounted includes a process for the connection or disconnection of each printed wiring portion of the first printed wiring directly or indirectly the The connection paths can be switched by processing for each of the first and second printed wirings or by selecting mounting of a component on the printed wiring .
As a result, the number of components mounted can be substantially the same as that of a single transistor output circuit, but a transistor output circuit using any type of output transistor can be configured simply by switching the connection of each printed wiring. As a result, the above-mentioned problems are solved on the assumption that the cost and the mounting area are substantially the same as those of one transistor output circuit.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, although applied to the programmable controller as a control apparatus in embodiment, it is not limited to this. In short, the control device includes a response element such as a light receiving transistor that responds to a signal processed by the internal circuit, and an output transistor that turns on and off the power to the load by a signal output from the response element. Any device having a transistor output circuit and a printed wiring board on which these elements and circuits are mounted is applicable.
[0013]
The printed wiring board of the present embodiment is driven by a power source and responds to a signal processed by an internal circuit of a control device, and a power output to the load is turned on / off by a signal output from the response element. In a printed wiring board having a printed wiring for mounting an output transistor to be turned off, a first printed wiring for switching a connection path of the power supply to the response element, and connection of a base of the output transistor to the response element A second printed wiring for switching the path, and the connection path can be switched by processing for each printed wiring or mounting selection of components on the printed wiring according to the type of the output transistor to be mounted. It is a thing. A programmable controller incorporating this printed wiring board will be described below.
[0014]
FIG. 1 is a circuit diagram showing an internal circuit and a transistor output circuit, which are main parts of a programmable controller, and output devices and power supplies connected thereto. FIG. 2 shows a printed wiring board built in the programmable controller of FIG. 1, for mounting the components of the internal circuit of the circuit of FIG. 1 and other components of the transistor output circuit excluding the light receiving diode. It is a principal part top view of a printed wiring board.
[0015]
First, referring to FIG. 1, 2 is a programmable controller, 4 is an output device, 6 is a power supply, 8 is an internal circuit, 10 is a transistor output circuit, 12 is a power supply terminal, 14 is an output terminal (OUT), and 16 is common. A terminal (COM), 18 is a light emitting diode, 20 is a light receiving transistor as a response element, 22 is a first resistor, 24 is a second resistor, 28 is a third resistor, and 30 is a fourth resistor.
[0016]
Here, reference numeral 26 denotes an npn type output transistor, but when the npn type is used as the output transistor, the first resistor 22 is connected between the collector of the light receiving transistor 20 and the power supply terminal 12 in the circuit of FIG. The two resistors 24 are connected between the emitter of the light receiving transistor 20 and the base of the output transistor 26, and the third resistor 28 and the fourth resistor 30 are both disconnected from the circuit and disconnected. In this case, the base current of the output transistor 26 is limited by the combined resistance of the first resistor 22 and the second resistor 24. When a pnp type output transistor 26a is used in which the output transistor is drawn out in a circle, the first resistor 22 and the second resistor 24 are both disconnected from the circuit and disconnected from the circuit in FIG. The third resistor 28 is connected between the collector of the light receiving transistor 20 and the base of the output transistor 26a, the fourth resistor 30 is connected between the emitter of the light receiving transistor 20 and the power supply terminal 12, and is a pnp type output transistor. 26a and the power source 6 are connected with the polarities shown by being drawn out by circles. In this case, the base current of the output transistor 26 a is limited by the combined resistance of the third resistor 28 and the fourth resistor 30.
[0017]
Referring to FIG. 2, reference numeral 32 denotes a printed wiring board according to the present embodiment. The printed wiring board 32 includes a pair of opposed lands a1 and a2 for solder connection for mounting the light receiving transistor 20, and a first For mounting a pair of opposing lands b1, b2 for solder connection for mounting the resistor 22, a pair of opposing lands c1, c2 for solder connection for mounting the third resistor 28, and a fourth resistor 30 A pair of opposed lands d1, d2 for solder connection, a pair of opposed lands e1, e2 for solder connection for mounting the second resistor 24, and an npn type output transistor 26 or a pnp type output transistor 26a. For this purpose, three lands f1, f2, and f3 for solder connection are formed. Further, the printed wiring board 32 is formed with a land g for solder connection to the power supply terminal 12, a land h for solder connection to the output terminal 14, and a land i for solder connection to the common terminal 16.
[0018]
Further, on this printed wiring board 32, a printed wiring 34 for connecting the collector of the light receiving transistor 20 to one end of the first resistor 22 is connected between the lands a1 and b1, and the other end of the first resistor 22 is connected to the power supply terminal 12 side. The printed wiring 36 to be connected between the lands b2 and g, the printed wiring 38 for connecting the emitter of the light receiving transistor 20 to one end of the second resistor 24, and the other end of the second resistor 24 to the output transistor 26 or The printed wiring 40 connected to the base of 26a is between the lands e2 and f1, and the printed wiring 42 connecting the collector of the output transistor 26 or 26a to the output terminal 14 side is between the lands f2 and h, and the emitter of the output transistor 26 or 26a. Is connected to the common terminal 16 side between the lands f3 and f. A printed wiring 46 connecting the first resistor to one end of the third resistor 28 is printed between the printed wiring 34 and the land c1, and a printed wiring 48 connecting the other end of the third resistor 28 to the base of the output transistor 26 or 26a is printed to the land c2. A printed wiring 50 connecting one end of the fourth resistor 30 to the emitter of the light receiving transistor 20 between the wiring 40 and the printed wiring 38 connecting the other end of the resistor 30 to the power terminal 12 side between the printed wiring 38 and the land d1. A wiring 52 is formed between the land d2 and the printed wiring 36, respectively.
[0019]
First, the case where the transistor output circuit 10 using the npn type output transistor 26 is mounted on the printed wiring board 32 having the above-described configuration with reference to FIGS. 3 and 4 will be described.
[0020]
In FIG. 3, the first resistor 22 and the second resistor 24 are connected, and the npn type output transistor 26 is connected, so that the connection path of the power supply terminal 12 to the light receiving transistor 20 (the printed wirings 34 and 36 are connected). Transistor output circuit 10 using an npn type output transistor 26 in which the connection path of the base of the output transistor 26 with respect to the light receiving transistor 20 (path to which the printed wirings 38 and 40 are connected) is switched. The circuit configuration is shown. For such a circuit configuration, components are mounted on the printed wiring board 32 as shown in FIG. That is, the light receiving transistor 20 is mounted on the opposing lands a1 and a2 by soldering, the first resistor 22 is mounted by soldering on the opposing lands b1 and b2, and the second resistance 24 is mounted on the opposing lands e1 and e2. Is mounted by soldering. An npn type output transistor 26 is soldered and mounted on the lands f1, f2, and f3.
[0021]
Next, using the printed wiring board 32 having the configuration described above with reference to FIGS. 5 and 6, the pnp type output transistor 26 a is used instead of mounting the transistor output circuit 10 using the npn type output transistor 26. A case where the transistor output circuit 10 is mounted will be described.
[0022]
In FIG. 5, the third resistor 28 and the fourth resistor 30 are connected, and the pnp type output transistor 26a is connected, so that the connection path of the power supply terminal 12 to the light receiving transistor 20 (the printed wirings 50 and 52 are connected). Transistor output circuit 10 using a pnp type output transistor 26a in which the connection path of the base of the output transistor 26 to the light receiving transistor 20 (path to which the printed wirings 46 and 48 are connected) is switched. The circuit configuration is shown. For such a circuit configuration, components are mounted on the printed wiring board 32 as shown in FIG. That is, the light receiving transistor 20 is mounted by soldering on the opposing lands a1 and a2, the third resistor 28 is mounted by soldering on the opposing lands c1 and c2, and the fourth resistor 30 is mounted on the opposing lands d1 and d2. Is mounted by soldering. A pnp type output transistor 26a is soldered and mounted on the lands f1, f2, and f3.
[0023]
As described above, in the present embodiment, since the output transistor is only npn type or pnp type, any output transistor is simply mounted on the connection land of the same printed wiring. Even in the configuration of the printed wiring board shared for mounting the components of the transistor output circuits of both types, the mounting area of the output transistor does not increase. In addition, the printed wiring board of this embodiment has a mounting area on the printed wiring board of either one of the transistors, regardless of which type of output transistor is used for mounting the component parts of the transistor output circuit. Even if the output circuit is mounted on the printed circuit board, only two printed circuit boards for resistance mounting are required. As a result, the total mounting area of the transistor output circuit is 2 Compared with the case where the component parts of the transistor output circuit are mounted, it is almost half, so that the printed wiring board can be reduced in size, and as a programmable controller device can be reduced in size and weight.
[0024]
In the above-described embodiment, the printed wiring is formed on one surface side of the substrate, but is not limited to this, and may be formed on the other surface side or both surface sides. Further, in the case of a laminated substrate, printed wiring may be formed in the substrate. The pattern shape of the printed wiring is not limited to the embodiment. In particular, when the substrate mounting component such as a resistor is a surface mounting type (chip component), the effect is further increased.
[0025]
In the above-described embodiment, the first resistor 22 and the third resistor 30 are mounted on the printed wiring board 32. However, the first resistor 22 and the third resistor 30 are not limited to the resistors 22 and 30, and instead of these, the coil The connection path may be switched indirectly even if it is a component such as the like. If necessary, the connection between the lands b1 and b2 and the lands d1 and d2 are disconnected depending on the type of output transistor to be used instead of a resistor or the like ( (Non-connection) or short-circuit (connection) may be indirectly performed with a switch, or simply short-circuit disconnection may be performed directly between these lands b1 and b2 or between d1 and d2. In this case, in the embodiment, the printed wirings 34, 36, 50, 52 constitute the first printed wiring, and the printed wirings 46, 48, 38, 40 constitute the second printed wiring. When the lands are connected by switches or soldering, other forms and patterns of printed wiring may be referred to as first printed wiring or second printed wiring depending on the function of the wiring. The present invention is not limited to the embodiment.
[0026]
In the above-described embodiment, the light receiving transistor 20 is used as a response element. However, the present invention is not limited to this, and the form of the element is not limited to a transistor. Any circuit or element that can be insulated can be used.
[0027]
【The invention's effect】
As described above, according to the present invention, a transistor output circuit using any type of output transistor can be mounted on a printed wiring board without substantially increasing the mounting area on the printed wiring board. When mounting components of both types of transistor output circuits on the same printed circuit board, the size of the printed circuit board can be reduced, wasteful mounting parts can be omitted, and each type of transistor output circuit can be mounted on separate printed circuit boards. As a result, the cost of the printed wiring board can be reduced as compared with the case where the component parts are mounted.
[Brief description of the drawings]
FIG. 1 is a circuit diagram showing a main part of a programmable controller according to an embodiment of the present invention, an output device connected to the programmable controller, and a power source. FIG. 2 is a plan view of a main part of a printed wiring board for component mounting constituting the circuit of FIG. 3 is a circuit diagram in the case of using an npn type output transistor in the circuit of FIG. 1. FIG. 4 is a plan view of a principal part of a printed wiring board corresponding to FIG. 3. FIG. FIG. 6 is a plan view of an essential part of a printed wiring board corresponding to FIG. 5. FIG. 7 shows an essential part of a conventional programmable controller, an output device connected thereto, and a power source. Circuit diagram [Fig. 8] Circuit diagram of the main part of another conventional programmable controller [Explanation of symbols]
2 programmable controller 4 output device 6 power supply 8 internal circuit 10 transistor output circuit 12 power supply terminal 14 output terminal 16 common terminal 18 light emitting diode 20 light receiving transistor 22 first resistor 24 second resistor 26 npn type output transistor 26a pnp type output transistor 28 3rd resistor 30 4th resistor

Claims (4)

A printed wiring board on which a light receiving transistor driven by a power supply and responding to a signal processed by an internal circuit and an output transistor for turning on / off a power supply to a load by a signal output from the light receiving transistor are mounted. In the built-in programmable controller,
The printed wiring board includes a first printed wiring for switching a connection path of the power supply to the light receiving transistor, and a second printed wiring for switching a base connecting path of the output transistor to the light receiving transistor. ,
The first printed wiring includes a printed wiring portion formed between the collector of the light receiving transistor and the power supply, and a printed wiring portion formed between the emitter of the light receiving transistor and the power supply. Yes,
Processing for each of the first and second printed wirings , including processing for directly or indirectly connecting or disconnecting each printed wiring portion of the first printed wiring according to the type of the output transistor to be mounted, or the printing A programmable controller characterized in that the connection path can be switched by selecting mounting of a component on wiring. 2. The programmable controller according to claim 1, wherein the second printed wiring includes a printed wiring portion formed between a collector of the light receiving transistor and a base of the output transistor, and an emitter and the base of the light receiving transistor. A programmable controller comprising: a printed wiring portion formed therebetween, wherein each printed wiring portion can be connected or disconnected directly or indirectly depending on a type of the output transistor. A response element that is driven by a power supply and responds to a signal processed by an internal circuit of a control device, and an output transistor that turns on / off a power supply to a load by a signal output from the response element In printed wiring boards with printed wiring,
The response element is a transistor (response transistor), a first print wiring for switching a connection path of the power supply to the response transistor , and a second print for switching a base connection path of the output transistor to the response transistor Wiring,
The first printed wiring includes a printed wiring portion formed between the collector of the response transistor and the power supply, and a printed wiring portion formed between the emitter of the response transistor and the power supply. ,
Processing for each of the first and second printed wirings , including processing for directly or indirectly connecting or disconnecting each printed wiring portion of the first printed wiring according to the type of the output transistor to be mounted, or the printing A printed wiring board characterized in that the connection path can be switched by selecting mounting of components on the wiring. 4. The printed wiring board according to claim 3, wherein the second printed wiring is a printed wiring portion formed between a collector of the response transistor and a base of the output transistor, an emitter of the response transistor, and the base. printed circuit board and a formed printed wiring portions, said to allow connection or disconnection of the respective printed wiring portions directly or indirectly depending on the type of the output transistor, and wherein the between.

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