JPH01295521A - Optical fiber type solid-state relay - Google Patents

Abstract

PURPOSE:To prevent sneak of noise and surge to an input circuit section and to prevent malfunction by arranging a light emitting element and a photodetector separately in a solid-state relay comprising input/output circuit sections and coupling optically both by an optical fiber. CONSTITUTION:A solid-state device 13 being an output circuit section B consists of a triac 18 switched by a photodetector 15 via a zero cross circuit 14 including the photodetector 15 and a control circuit. Then a load device 11 switched by the triac 18 such as a solenoid is connected in series with a power supply 19. In case of mounting the output circuit section B directly onto the load devices 11, 12, the output circuit section B is mounted very nearly to the load devices 11, 12 and a power line 19a. Then the side of the light emitting element 16 of all input circuit section A is provided remotely by using an optical fiber 17, bypass of noise from a noise generating source such as the load devices 11, 12 is prevented and malfunction of a low voltage control circuit 20 is prevented.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a solid state relay, more specifically, an optical fiber type solid state relay (hereinafter referred to as SSR) that can remotely control input and output using an optical fiber.
Regarding.

[Conventional technology]

Conventionally, this type of SSR, as shown in FIG. 3, has an input circuit section consisting of a photocoupler light emitting diode 2 which is a light emitting element that operates at a low DC voltage, and a photocoupler which is a light receiving element driven by the optical output of the light emitting diode 2. It consists of an output circuit section consisting of a phototransistor 3 of a coupler and a triac 5 of an output semiconductor switching element which is switched by the phototransistor 3 via a zero cross circuit 4, and each circuit section is housed in one 5SRI and arranged. It is set up. The appearance of 5SRI is based on fallen trees in Jitsugoku Publication No. 70356 (Fig. 1)
As disclosed in Japanese Patent No. 536 (FIG. 1), it is arranged in one housing.

[Problem to be solved by the invention]

The 5SRI explained in the conventional example uses a photocoupler to optically connect the input circuit section and the output circuit section, so that noise and surges generated in the output circuit section are prevented from being transmitted to the input circuit section to some extent. However, since the connection point between the input circuit section and the output circuit section is within the same SSR1 housing, and is also provided within a single electronic component, the photocoupler, The output circuit parts are very close to each other, and even though they are optically coupled to avoid the effects of electrical noise and surges, the load may still be transmitted between the terminals of the photocoupler or the outer surface of its package. Noise and surges generated in the equipment 7 and the power line 6a enter the input circuit side and cause the low voltage control circuit 8 connected to the input of the SSR 1 to malfunction.
Furthermore, if the noise or surge is large, there is a problem that the SSR1 itself may malfunction.

The present invention has been made to address the above-mentioned problems and aims to provide an optical fiber type solid state relay that does not malfunction due to noise.

[Means to solve the problem]

In order to achieve the above object, the SSR of the present invention optically connects the isolated light emitting element and light receiving element with an optical fiber.

[Effect]

Since the output circuit section, which generates noise and surges when the load is switched on and off, is separated from the input circuit section using optical fibers, it is possible to prevent noise and surges from entering the input circuit section as much as possible.

〔Example〕

An embodiment of the present invention will be described below based on the drawings.

As shown in FIGS. 1 and 2, the solid state device 13, which is the output circuit section B, is operated by the light receiving element 15 through a zero cross circuit 14 including a light receiving element 15 such as a phototransistor driven by optical input and a control circuit. It consists of a triac 18 which is switched. Reference numeral 11 denotes a load device (such as a solenoid) that is opened and closed by the triac 18 and is connected in series to a power source 19 .

The light receiving element 15 is optically coupled to one end of an optical fiber 17, which is completely unaffected by electrical noise and surges, by an optical connector or the like, and the other end of the optical fiber 17 is connected to the load device 1.
The light emitting element of the input circuit section A is generally arranged on the surface of the control panel or inside the control panel by extending the required length from the output circuit section B installed near the load such as 1 or a part of the control panel. 16 (for example, a light emitting diode) by an optical connector or the like. 20 is a low voltage control circuit connected to the input circuit section, which controls the present SSR.

FIG. 2 shows an embodiment in which the output circuit section B is directly attached to the load equipment 11.12, and the output circuit section B shows the load equipment 11.12 and the power supply line that generate excessive noise and surges. 19a, but the light emitting element 16 side of the input circuit section A can be installed far away by means of the optical fiber 17, which prevents noise from entering the noise source such as the load equipment 11, 12, etc., and enables low voltage control. circuit 2
0 malfunction can be prevented.

[Effects of the present invention]

As described above, the present invention deals with noise generated by load switching,
By isolating the input circuit section to which the low voltage control circuit is connected from the output circuit section close to the surge source using optical fiber, noise and surges generated from the load can be prevented from entering the input circuit section, preventing malfunctions. It is possible to obtain an optical fiber type solid state relay that can operate stably.

[Brief explanation of the drawing]

1 and 2 each show an embodiment of the present invention, in which FIG. 1 is an internal circuit diagram and FIG. 2 is a circuit diagram including a partial side view of the actual body. 3 to 4 each show conventional examples,
FIG. 3 is an internal circuit diagram, and FIG. 4 is a circuit diagram including a partial side view of the actual structure. 15... Light receiving element, 16... Light emitting element, 17...
Optical fiber, 18...triac, A...input circuit section, B...output circuit section Patent applicant Toshimaru Takemoto, patent attorney representing Matsushita Electric Works Co., Ltd. (and 2 others)

Claims (1)

[Claims] 1) In a solid state relay consisting of an input circuit section consisting of a light emitting element, etc., and an output circuit section consisting of a light receiving element that receives light from the light emitting element and drives a triac, the light emitting element and the light receiving element are separately isolated. An optical fibre-type solid-state relay is characterized in that the relay is arranged in the same direction and is optically coupled between the two using an optical fiber.