JP3032558B2 - Switch with indicator light - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switch with an indicator light that can confirm the operation state of a load.

2. Description of the Related Art Conventionally, in a switch with an indicator light of this type, a current transformer is inserted and connected to a main circuit, and an output is obtained from a secondary side of the current transformer in accordance with a magnitude of a load current. The display element was turned on.

[Problem to be Solved by the Invention] In such a conventional example, a current transformer is used, so that the manufacturing cost is increased. In addition, since the transformer has a secondary current that differs depending on the magnitude of the primary current, the display element There is a problem that the brightness of the image changes. Further, when a surge current flows on the primary side of the current transformer, there is a problem that the display element is easily broken.

The present invention has been provided in view of the above points,
An object of the present invention is to provide a switch with an indicator light for the purpose of reducing a change in brightness of a display element due to a magnitude of a load current and making it hard to fail even when a surge current flows.

[Means for Solving the Problems] The present invention relates to a rectifier block comprising a diode connected in a bridge shape, and a diode further connected in a forward direction between both output terminals of a rectifier circuit constituted by these diodes; A display block comprising two light emitting diodes connected in reverse parallel to each other between two input terminals of the rectifier circuit via a choke coil, and a switch unit connected in series with the display block. It is.

[Operation] By using the voltage drop of the rectifying block, the light emitting diode of the display block is turned on with a small change in brightness, and the light emitting diode is prevented from a surge current by a choke coil. Therefore, it is hardly affected by the surge current.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1 shows a circuit diagram of the switch body A. The electrical circuit configuration is composed of a rectifying block 1, a display block 2, and a switch SW of an opening / closing mechanism. Rectifier block 1 connects the diode D ₁ to D ₄ like a bridge, further, the diode D ₁ and is connected to the anode of the diode D ₅ to the connection point of the cathodes of the D _4, the diode cathode of the diode D ₅ D It is connected to the connection point of the anodes of ₂ and D _3. The display block 2 includes two light emitting diodes LED ₁ and LED ₂ connected in parallel in the opposite direction, and a choke coil L ₁ . The display block 2 is connected to the input / output terminal of the rectification block 1.

The switch body A is interposed between the power supply V and the load L. Now, when the switch section SW is on, the diodes D _{1 to} D ₅ are alternating current power sources, so that a current in a solid line direction and a current in a broken line direction flow alternately. That is, in the positive half cycle of the AC power supply, as shown by the solid arrow,
The current flows from D ₁ → D ₅ → D ₃ → load L, and in the negative half cycle, the current flows from load L → diode D ₄ → D ₅ → D ₂ .
Then, since the voltage drop of the diode D ₁ to D ₅ is almost constant less affected by the magnitude of the load current, a-b
A constant potential difference always occurs between them. Therefore, this a-
Since the potential difference between b supplies a substantially constant current to the light emitting diodes LED ₁ and LED ₂ , the light emitting diodes LED ₁ and L
The brightness of ED ₂ does not change much, and becomes almost constant.

Here, the forward voltage drop per diode is about 0.7V. Also, the forward voltage drop of the light emitting diode is, for example, in the case of a gallium phosphorus element,
Since it is about 1.8 V and about 1.5 V in the case of a gallium aluminum arsenic element, it is necessary to connect three diodes in series in order to pass a current through the light emitting diodes LED ₁ and LED ₂ . When the present invention to connect the diode D ₁ to D ₅ as shown in FIG. 1, regardless of the direction of the load current, to flow in the same direction of the current in the diode D _2, diodes total of five may be.

However, when a series circuit of three diodes is connected in parallel as shown in FIG. 2 to turn on the light emitting diodes, a total of six diodes are required. That is, by connecting as shown in FIG. 1 of the present invention, one diode can be reduced.

By the way, in the case of a switch with a built-in semiconductor, when an element breaks down due to factors such as an inrush current at power-on, an induced lightning surge induced on a power supply line, and an electrostatic discharge received by a person during operation, the switch becomes non-conductive. Can be considered.

Figure 3 shows the current waveforms of the diodes D ₁ to D ₅ of the circuit of FIG. 1, the same figure (a) is the load current, the same figure (b) is a diode D _1, D ₃ current, the FIG. 3C shows the current of the diodes D ₂ and D ₃ , and FIG. 4D shows the current of the diode D ₅ . The diode D _5, compared to other diodes D ₁ to D ₄ current flows only one side of the half-cycle, a current flows over both half cycles, there is a high probability that the diode D ₅ is faulty and non-conductive. When the diode D ₅ becomes non-conductive, the entire rectifier block 1 becomes non-conductive, the load current will flow all the display block 2. This means that if the load current is within the rating of the light emitting diodes LED ₁ and LED ₂ , the switch body A can be used without any problem, but if the load current is higher than the rating, the light emitting diodes LED ₁ and LED ₂ fail and the switch body A Becomes non-conductive.

In this regard, in the case of the circuit as shown in FIG. 2 in which a plurality of diodes are simply connected in series and parallel, the probability that all of the diodes D _{1 to} D ₆ fail is constant, and if the diode D ₁ fails, and load current emitting diodes LED _1, LED ₂
If the light-emitting diodes LED ₁ and LED ₂ fail at the rated value or more, a half-wave rectified current flows as indicated by a broken line in the circuit. Since the rated current of the light emitting diode is as small as several tens of mA, the load current is usually higher than the rated current in most cases.

In such a state, the load L is adversely affected, and in the worst case, the load L may be broken or burnt, which is dangerous. However, according to the circuit configuration shown in FIG. 1 of the present invention, as described above, there is a high probability that the entire switch body A becomes non-conductive, and a failure occurs in a safe mode.

FIG. 4 shows a comparison between the load current of the switch body A of the present invention and a conventional switch with a built-in current transformer and the brightness of the light emitting diode. As is apparent from FIG. 4, the change in brightness of the switch body A of the present invention is smaller than that of the current transformer type regardless of the magnitude of the load current.

Next, a description will choke the role of the coil L ₁ connected in series with the light emitting diodes LED _1, LED _2. As described above, when an inrush current and a surge current flow through the load circuit, these currents naturally flow through the rectifier block 1 and the display block 2.
Rectifier diodes D ₁ to
D _5, the light emitting diodes LED _1, LED ₂ and is excellent in relatively durable compared, light emitting diodes LED _1, LED ₂ is very weak,
Diodes D _{1 to} D ₅ are light-emitting diodes LED ₁ and LED ₂ even if they are safe.
It is possible that only a failure occurs.

Inrush current or surge current peak value is very high, the pulse width is very short, the number μsec~ number msec, since the current change amount .DELTA.i / Delta] t per unit time is very large, the choke coil L ₁ It is hard to pass. When protecting the light emitting diodes LED _1, LED ₂ in the choke coil L _1, light-emitting diodes LED _1,
LED ₂ is less susceptible to inrush and surge currents, and therefore less prone to failure. Also, for steady current, the impedance is not so large, so the light emitting diode LE
It does not hinder the power supply to D ₁ and LED ₂ . For the above reasons, by inserting a choke coil L _1, a light emitting diode LE
D ₁ and the stable current supply of the LED ₂ can be realized.

Next, a specific configuration of the switch body A will be described with reference to FIGS. Body of switch body A is body 4
And a cover 5, and terminal portions 6 connected to external electric wires are formed on both sides of the body 4, respectively. The terminal portion 6 includes a substantially U-shaped terminal plate 7, a substantially S-shaped locking spring 8 for press-connecting a conductor of an electric wire to the terminal plate 7, and a release button 9 for releasing the electric wire. I have. An electric wire insertion hole 10 for inserting an electric wire and a release hole 11 for inserting a tip of a driver or the like to press the release button 9 are formed in the bottom of the body 4.

A rib 12 made of an insulating material is integrally protruded from a substantially central portion of the body 4, and storage portions 13 and 14 are formed with the rib 12 as a boundary. An opening / closing mechanism is housed in one storage unit 13. That is, the support plate 15 electrically connected to the one terminal plate 7 is disposed at the bottom of the storage portion 13, and the substantially U-shaped opening / closing body 17 swings on the protrusion 16 formed on the support plate 15. It is arranged freely. A movable contact 18 is fixed to one side surface of the opening / closing body 17, and a fixed contact 19 facing the movable contact 18 is provided on the other terminal plate 6.

A handle 21 is provided in the opening 20 of the cover 5, and the lower surface of the actuator 22 protruding from the lower surface of the handle 21 abuts on the upper end of the opening / closing body 17. The contacts 18 and 19 are opened and closed by operating the seesaw. The contacts 18, 19 constitute the switch section SW shown in FIG.

The diode D _{1 of the} rectifying block 1 is provided in the other storage portion 14.
To D ₅ and the printed board 23 mounted with the choke coil L ₁ is OsameSo. Also, the light emitting diode LE of the display block 2
The display 24 in which D ₁ and the LED ₂ are integrated is mounted on another printed circuit board 25, and the printed circuit board 25 is fixed to the lower surface of the handle 21. The two printed boards 23 and 25 are connected by a lead wire 26. Here, the printed circuit board 23,2
5, grooves 27 and 28 are formed respectively, and the lead wire 26 is slightly slackened from the soldered portion at the end of the lead wire 26 so that the lead wire 26 is
It is fixed at 8. This means that even if the handle 21 is inverted,
This is to prevent the soldered portion of the lead wire 26 from breaking. The printed circuit board 23 and the terminal plate 7 are also connected to the lead wires 29.
Connected by

The upper surface of the display body 24 of the printed circuit board 25 fixed to the handle 21 is located corresponding to the display hole 30 of the handle 21,
The load state can be visually recognized from the outside of the handle 21.

Here, the switch main body A of the present invention is formed in a size of one standardized wiring appliance module, and is detachably mounted on a standardized mounting frame. On both sides of the cover 5, locking claws 31 are attached to the mounting frame so as to protrude laterally.

FIG. 9 shows a switch frame A with a plate frame 32 as a mounting frame.
The exploded perspective view when attaching to the plate frame is shown.
Reference numeral 32 denotes a size in which three switch bodies A each having the size of one standardized wiring appliance module can be mounted. still,
The body 4 of the switch main body A and the cover 5 are connected by an assembly frame 33, and the above-described locking claw 31 is formed on the assembly frame 33. A pair of locking holes 34 into which a pair of locking claws 31 of the switch body A are inserted and locked in one side piece of the plate frame 32.
Are formed. Further, a bending piece 35 that can be bent to the side is formed integrally with the other side piece of the plate frame 32,
The other pair of locking claws 31 of the switch main body A is inserted and locked into the pair of locking portions of the bending piece 35, so that the switch main body A is detachably mounted on the plate frame 32.
Further, the plate frame 32 has a mounting hole 36 for screw insertion for mounting on a switch box embedded in the wall surface.

A decorative plate 37 is mounted on the front surface of the plate frame 32, and an engaging claw 38 is provided on the rear surface.
By fitting 38 into the engagement hole 39 of the plate frame 32, the decorative plate 37 is detachably attached to the plate frame 32. An opening 40 for exposing the handle 21 of the switch body A is formed in the decorative plate 37.

[Effects of the Invention] As described above, the present invention provides a rectifier block in which diodes are connected in a ridge shape and a diode is further connected in a forward direction between both output terminals of a rectifier circuit configured by the diodes. A display block comprising two light emitting diodes connected in reverse parallel to each other between two input terminals of the rectifier circuit via a choke coil, and a switch unit connected in series with the display block. Therefore, by using the voltage drop of the rectifier block to light the light emitting diodes of the display block with a small change in brightness, the light emitting diodes can be manufactured at a lower cost than the conventional one using a current transformer, and furthermore, the diode of Since the light-emitting diode is turned on using the voltage drop, the brightness of the light-emitting diode does not significantly change with the load current. In addition, the surge current is blocked by the choke coil in the light emitting diode, making it less susceptible to the surge current. This is advantageous in that it is difficult to cause a failure.

[Brief description of the drawings]

1 is a circuit diagram of an embodiment of the present invention, FIG. 2 is an explanatory diagram of the above embodiment, FIG. 3 is an operation waveform diagram of the above embodiment, and FIG. 4 is a characteristic diagram showing load current and brightness of a light emitting diode of the embodiment. FIG. 5 is a cross-sectional view of the switch body, FIG. 6 is a plan view of the switch body with the cover removed, FIG. 7 is a perspective view of a main part of the switch, FIG. FIG. 9 is an exploded perspective view showing the construction state of the above. 1 rectifier block, the display block 2, D ₁ to D ₅ are diodes, LED _1, LED ₂ is a light emitting diode, SW switch unit.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01H 9/16 H01L 33/00

Claims (1)

(57) [Claims] 1. A rectifier block comprising diodes connected in a bridge and a diode further connected in a forward direction between both output terminals of a rectifier circuit constituted by these diodes; A display switch comprising: a display block formed by connecting two light emitting diodes connected in anti-parallel to each other through a choke coil; and a switch unit connected in series to the display block.