JPH01295523A - Optical fiber type solid-state relay - Google Patents

Abstract

PURPOSE:To avoid malfunction due to noise by connecting one end of an optical fiber to a photodetector of an output circuit section and coupling other end to an input circuit section optically arranged separately from the output circuit section in a solid-state relay of zero cross type. CONSTITUTION:A photodetector 15 is connected optically to one end of an optical fiber 17 not susceptible to the effect of electric noise or surge. Then the optical fiber 17 is prolonged by a required length and a light emitting element 16 such as a light emitting diode of the input circuit section A is connected to the other end stably optically. In case of mounting the solid-state device 13 to load devices 11, 12 directly, the input wire to the input circuit section A is wired by using the optical fiber 17 without any effect of electric noise. Thus, noise induction from other load device or power line being noise resource as well as noise 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 SSR 1 and arranged. It is set up. The appearance of 5SRI is shown in, for example, Japanese Utility Model Publication No. 1983-70356 (Fig. 1) and Japanese Utility Model Publication No. 57-70
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, if this 5SRI is mounted directly on the load 7 as shown in Figure 4, the noise and surge generated in the load 7 and power line 6a will be transmitted through the input line 1a, resulting in low There was a problem in that the low voltage control circuit 8 and the SSR 1 themselves malfunctioned due to the leakage to the voltage control circuit 8.

In addition, if the SSR 1 is not directly attached to the load 7 but is mounted on the inner surface of the control panel, the load 7 and the power line 6
In addition to a, input line 1a may be damaged due to loads from other sources or high voltage wires.
Noise and surges are induced in the low voltage control circuit 8.
There was a problem that it would 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 purpose, this SSR is equipped with a zero cross circuit on the output side that opens and closes the load near zero phase, and one end of the optical fiber is optically coupled to the light receiving element of the output circuit section, and the other end is extended, and the input is isolated. Optically coupled to the circuit.

[Effect]

Even though the output circuit section is located near noise sources such as loads, the input circuit section is isolated from the output circuit section using optical fibers, so the wiring of the input control circuit is not affected by noise or surges. Since the L'f'o cross circuit is provided in the output circuit section, noise and surge generated when switching the load can be suppressed.

〔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 connected to a light receiving element 15 such as a phototransistor driven by optical input and a zero cross circuit 14 for switching the load at zero cross phase. It consists of a triac 18 that is switched by the light receiving element 15. Reference numeral 11 denotes a load device (for example, a solenoid, etc.) that is opened and closed by the triac 8 and is connected in series to a power source 19.

The light receiving element 15 is optically connected to one end of an optical fiber 17 that is not affected by electrical noise and surges,
The optical fiber 17 is extended by a required length, and a light emitting element 16 such as a light emitting diode of the input circuit section A is optically stably connected to the other end. 20 is a low voltage control circuit connected to the input circuit section, which controls the present SSR.

In FIG. 2, the solid state device 13 is connected to the load equipment 11.
．． 12, in which the solid state device 13 of the output circuit section B is installed very close to the load equipment 11.12 and the power line 19a that generate excessive noise or surges. However, the optical fiber 17 allows input wiring to the input circuit section A to be carried out without being affected by electrical noise, and noise from the noise load devices 11 and 12, as well as other load devices and power lines that are noise sources, can be wired. Low voltage control circuit 20 that can also prevent induction
Malfunctions can be prevented.

In addition, as mentioned above, this SSR has the zero cross circuit 14 in the output circuit section B, and the load switching is performed near the zero phase, so the noise and surge that occur when switching the load can be suppressed as much as possible. This makes it possible to further improve noise resistance and surge characteristics.

[Effects of the present invention]

As described above, the present invention uses an optical fiber to isolate the input circuit section far from the output circuit section provided near a noise source such as a load, and connects the low-voltage side wiring, which is susceptible to noise, to the optical fiber. Because this is done in the output circuit, it is not subject to noise induction from the load connected to the output circuit, other load equipment, high-voltage power lines, etc., and malfunctions can be prevented.
In addition, noise and surges during load switching can be suppressed as much as possible by the zero-cross circuit provided in the output circuit section, and an optical fiber type solid state relay that is further free from malfunctions can be obtained.

[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 partially actual side view. 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: Matsushita Electric Works Co., Ltd. Patent attorney Toshimaru Takemoto (and 2 others) Figure 1''B 2 Figure II3 Figure 114 Figure

Claims (1)

[Claims] 1) A zero-cross type circuit 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 via a zero-cross circuit. An optical fiber in a solid-state relay, characterized in that one end of the optical fiber is connected to a light receiving element of the output circuit section, and the other end of the optical fiber is optically coupled to an input circuit section that is isolated from the output circuit section. solid state relay.