JPS6318925A - Surge absorber for protection against over-voltage and over-current - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention is based on a! Regarding the surge absorption element that protects the continuous overcurrent passage from current loads, this surge absorption element specifically prevents the absorption element from overheating and also prevents the continuous overcurrent passage from flowing into the equipment side. Regarding.

[Prior Art] In general, a surge absorbing element is used by installing a surge absorbing element with an operating voltage higher than the maximum operating voltage of the circuit to which the surge absorbing element is installed, and then applying an instantaneous surge current such as a lightning surge current to the circuit. The thermal absorption element operates only when an overvoltage enters the circuit, and protects the electronic components attached to the circuit. Therefore, as a general characteristic of surge absorbing elements, at voltages below the operating voltage of the surge absorbing element, it usually has high resistance, but at voltages above the operating voltage of the surge absorbing element, it has a low resistance of several tens of Ω or less. becomes the resistance value. Because the surge absorption element has such characteristics, when continuous overvoltage and overcurrent is applied to the surge absorption element,
A t current flows through the surge absorbing element at all times, causing the surge absorbing element to generate heat and eventually cause a fire.

Normally, it is unthinkable that such continuous overvoltage and overcurrent could be applied to a circuit, but the idea of taking maximum safety measures in case of unexpected situations is becoming more and more widespread. An example of this is UL (Ltnderwriter') in the United States.
s Laboratories Inc.) has already adopted the concept of preventing equipment from igniting if such continuous excessive tEA current is applied, which could eventually cause a fire.

It is becoming standardized. In line with this, similar safety standards are being adopted for 6-engine construction.

[Problems to be Solved by the Invention] In the case of such a continuous overvoltage-current load, one problem is the influence on the serve absorption elements attached to the two devices. Currently, many devices are equipped with surge absorption elements, and there are no countermeasures against equipment malfunction or destruction caused by induced lightning, etc., but the surge absorption elements are generally installed at points that are not fully connected to the equipment. power line (usually commercial
OV, etc.) or the entrance to a telephone line (such as a telephone line, etc.).

This is because such a surge absorption element exhibits a low resistance value against overvoltage as explained above, and at that time,
There is a danger that it will become a kind of heating element and cause fire in two devices.

The present invention provides a surge absorbing element that includes protection against one or more continuous overcurrent loads.

That is, the purpose of the present invention is! ! The present invention provides a safe surge absorbing element that eliminates the risk of heat generation in the surge absorbing element due to general overvoltage and overcurrent. In addition, two purposes of the present invention are:
To provide a surge absorbing element that can protect the surge absorbing element from overheating when a continuous overcurrent passes through it, and at the same time prevent continuous overvoltage and overcurrent from flowing into an electronic circuit (equipment).

[Means for Solving the Problems] The present invention provides a method in which a temperature fuse is installed in close contact with the surface of a surge absorption element, and the temperature fuse is connected in series with the surge absorption element and an electronic circuit (equipment). This is a surge absorbing element that can protect against continuous overcurrent and current loads.

In the present invention, 1. The thermal fuse is installed in close contact with the surface of the surge absorbing element, and when the temperature fuse melts due to the heat generated by the surge absorbing element and blows, it is electrically connected in series to the surge absorbing element and the electronic circuit (equipment). Thermal fuse breaks the circuit and continues to pass through t′lrE.
This protects the surge absorbing element from damage and at the same time prevents continuous overcurrent from flowing into the electronic circuit.

Although it is normally unthinkable that a current passing through a continuous overcurrent is applied to a device's electronic circuit, leakage from the power supply, leakage from other power supply circuits, induced current, etc.
The commander may be forced to pass an overcurrent. In such a case, the surge absorbing element is protected to prevent it from emitting smoke or igniting.

In the surge absorbing element of the present invention, after attaching one of the lead wires of the temperature fuse to one of the lead wires of the surge absorbing element such as a gap type discharge tube or a microgap type discharge tube, the temperature fuse is connected to the surface of the surge absorbing element. The other side of the temperature fuse lead wire was installed as a new third wood lead wire.This third wood lead wire was connected to the t source or communication edge.The so-called .

It is a three-terminal type surge absorption element. This three-terminal surge absorbing element has a lead wire that can be connected to the electronic circuit (equipment) side, and a lead wire that can be connected to the raw wire or communication line.
Although they are different and have polarity, the present invention also takes into consideration a three-terminal surge absorbing element having a structure that does not have polarity.

To explain in detail, in order to prevent this three-terminal surge absorbing element from having polarity, two temperature fuses are attached in parallel to one lead wire of this surge absorbing element, and then these temperature fuses are connected to the surge absorbing element. The two lead wires from these two parallel temperature fuses are now used as the lead wire portion of the three-terminal surge absorbing element. In this case, temperature fuses are attached to two of the three lead wires of this three-terminal surge absorbing element. Therefore, it is possible to attach it to a single circuit board without particularly considering the polarity. That is, it is sufficient to connect one of the two lead wires to the power supply side and the other to the device circuit.

Further, according to the present invention, a device in which the surge absorbing element lead wire and the temperature fuse lead wire are each provided with a total of four lead wires independently can be manufactured according to the present invention.

In other words, it is possible to manufacture a circuit having a configuration in which each device circuit or absorption element circuit can be independently interrupted.

In this way, in the surge absorbing element of the present invention, by bringing the temperature fuse into close contact with the surface of the absorbing element, when the surge absorbing element generates heat due to continuous overvoltage and overcurrent, the generated heat causes the surface of the surge absorbing element to By melting and blowing the temperature fuse that is in close contact with the electronic circuit, the continuous overcurrent passage tfM is cut off, and at the same time, the continuous overvoltage and overcurrent are also prevented from flowing into the electronic circuit (equipment) side.

A continuous overcurrent passing through the current is applied to an electronic circuit.
Although normally unthinkable, leakage from the power supply, other t*,
Overvoltage and overcurrent may be applied continuously due to leakage current or induced current from the circuit. In such a case, the purpose is to protect the serve absorption element and prevent it from emitting smoke or igniting. At the same time, an absorption element having a structure that protects the 7 equipment circuits from such an overvoltage-carrying current load can be created.

As for the temperature fuse used in the present invention, the lower the operating temperature, the faster the blowout time, but the attachment to the board must be selected in consideration of the workability. Also, the higher the current rating, the stronger the current resistance.

Table 1 shows the test results of the operating temperature and blowing time of the temperature fuse when overvoltage and overcurrent are applied.

The shape of the surge absorbing element and the temperature fuse is not particularly limited, but it is preferable to use a shape that allows heat generated by the surge absorbing element to be efficiently conducted to the temperature fuse.

The structure of the surge absorbing element of the present invention as described above is as follows.

It is as follows.

That is, the surge absorbing elements include absorption elements based on gap type discharge tubes and improved microgap type discharge tubes. These surge absorbing elements are configured to cut off the surge absorbing element circuit and/or device circuit for protection when the surge absorbing element overheats due to continuous overvoltage and overcurrent.

The surge absorbing element of the present invention has a simple structure and can prevent dangers such as fire due to the application of overvoltage and overcurrent.

The absorbing element of the present invention has a structure shown in FIG. 1A. 1st
In Figure A, a temperature fuse 13 according to the present invention is fixed to the gap type discharge tube 11 with a stainless steel wire 16, and the temperature fuse 13 is fixed to the gap type discharge tube 11 in close contact with the discharge tube 11.
Connect the lead wire 14 with the caulking 15, and
2 terminal, and the lead on the opposite side of discharge tube 11! i12
” terminal and the lead wire 1 on the opposite side of the temperature fuse 13
This is an absorption element with a three-terminal structure of 4゛ terminals.

The circuit assembly configuration of this absorbing element is shown in FIG. 1B. In the absorbing element of the present invention, a discharge tube 21 and a temperature fuse 22 are connected in series (structurally, an adhesive film Ra is formed), and the absorbing element The circuit 21 is connected in parallel with the power supply or communication line source 23 and the equipment circuit 24, while the temperature fuse 22 is connected in series with the power supply 1 communication line source 23 and the equipment circuit 24.

FIGS. 2A and 2B are cross-sectional views showing the structure of another example of the surge absorbing element of the present invention. That is, the structure of a micro-gap discharge tube 31 assembled according to the present invention is shown in FIG. 31 lead wire 32 and temperature fuse 33
With the terminal made by connecting the glued wire 34 with the caulking 35.

With the lead wire 32° terminal on the opposite side of the discharge v31.

Terminal 3 of lead 34' on the opposite side of temperature fuse 33
This is a surge absorption element with a terminal configuration.

A circuit diagram of this absorbing element is shown in FIG. 2B. The absorbing element of the present invention includes a discharge tube 41 and a temperature fuse 42.
is tangent in series a! I'm pissed. The temperature fuse 42 is connected in parallel with the power supply 1 communication line 43 and the equipment circuit 44, while the temperature fuse 42 is connected in parallel with the power supply 1 communication line 43 and the equipment circuit 44.

3A and 3B show a surge absorbing element according to the present invention in a non-polar configuration, and FIG. 3A is an assembled view of this configuration. Two temperature fuses 53 and 54 are installed in close contact with the microgap discharge tube 51 as a surge absorbing element.

Lead wire 52 of discharge tube 51 and temperature fuses 53 and 54
The lead wires 57 and 58 are connected and fixed by caulking 55. The two temperature fuses 53 and 54 are symmetrically connected to the discharge tube 51.

The absorbing element with this configuration has three terminals: the lead wire 50 on the opposite side of the caulked lead wire of the discharge tube 51, and the lead wires 59 and 60 on the opposite side of the caulked side of the temperature fuse 53, 54. Assembled to have. Therefore,
The terminal configuration for connecting to the source side and device circuit side is non-polar.

FIG. 3B is a circuit diagram illustrating this installation circuit. The microgap discharge tube 61 is connected to a power source 64 and an equipment circuit 6.
5, but two temperature fuses 62, 63 are each connected in series with source 64 and equipment circuit 65. When an overvoltage/overcurrent is applied from the power supply 64 to the M controller, the discharge tube 61 first generates heat, and when it becomes overheated, the temperature fuses 62 and 63 melt, causing a continuous overvoltage to be applied to the discharge tube 61. At the same time as the current is cut off, the equipment circuit is also cut off due to the fusing of 63, and the overcurrent passing through the A-controller is protected from current. In addition, the characteristics of the temperature fuse are changed appropriately, so that first the temperature fuse 63 is blown to protect one device circuit, and if it is left as is, the circuit for the discharge tube is kept alive by the temperature fuse 62. , temperature fuse 62
It can also be configured to fuse and cut off the N-master overvoltage and overcurrent.

Next, the surge absorbing element of the present invention will be explained using a first concrete example, but the present invention is not limited to the second embodiment.

[Embodiment 1] An embodiment of the present invention of a surge absorbing element for a co-gap type discharge tube will be explained with reference to FIG. 1A.

After closely reading one lead wire portion 12 of the gap type discharge tube 11 and one lead wire portion 14 of the temperature fuse 13 by caulking 15, the gap type discharge tube 11 and the temperature fuse 13 are brought into close contact with each other. It is fixed by a line 16. Lead wire 14 is on the power supply side, lead wire 12 is on the power supply side.
has three lead wires so that it can be wired to the child circuit (equipment) side. This is a so-called three-terminal gap type discharge tube.

By installing a temperature fuse on the source side, you can avoid continuous overheating! When an overpressure current of 1i is applied to a gap type discharge tube, the temperature fuse is blown due to the heat generated by the gap type discharge tube, and as a result, a continuous overcurrent and positive pressure is applied to the gap type discharge tube. zu, and.

Also on the electronic circuit (m device) side! ! This is a surge absorption element that can prevent excessive overvoltage and overcurrent from being applied.

FIG. 1B shows a circuit diagram of the installation of the gap type discharge tube according to the invention; ! When a typical overvoltage and overcurrent is applied, the gap type discharge tube 21 first generates heat, but this heat generation causes the temperature fuse 22 to
This cuts off the continuous overvoltage and overcurrent applied to the gear type discharge tube 21, and at the same time prevents the continuous overvoltage and overcurrent from being applied to the electronic circuit 24.

Table 2 shows the test results for the configurations according to the two embodiments.

The material of the substrate in Table 2 is Bakelite, and the temperature fuse used is of a type operating at 7A: 115°C.

From the results in Table 2,! ! When a standard overvoltage and overcurrent is applied to a gap-type discharge tube, the temperature fuse will blow out in about 10 to 30 seconds without causing smoke or ignition on the board, and the temperature will reach 1 m.
It is clear that the system has blocked the overvoltage and overcurrent.

[Embodiment 2] A surge absorbing element for a microgap discharge tube according to the present invention is shown in FIG. After these are connected by caulking 35, the micro-gap discharge tube 31 and temperature fuse 33 are brought into close contact with each other and fixed with stainless steel wire 36. This is a so-called 3-terminal micro gear type discharge tube having three lead wires such that the lead wire 34' is wired to the electric side I and the lead wire 32 is wired to the sub circuit (equipment) (II).

By installing a temperature fuse on the source side, when continuous overvoltage and overcurrent HE is applied to the micro gear knob type discharge tube, the temperature fuse will melt due to the heat generated by the discharge tube.
As a result, one circuit is completely cut off, and continuous overvoltage and overcurrent are not applied to the discharge tube, and continuous overvoltage and overcurrent cannot be applied to the child circuit (equipment) side.

FIG. 2B shows an installation circuit diagram. In this installation circuit diagram, when a continuous flow of A71L pressure is applied from the source 43, the microgap discharge tube 41 first generates heat; The thermal fuse 42 melts and blows out due to the heat generated, cutting off the continuous overcurrent that has been applied to the micro-gap discharge tube 41, and also cutting off the circuit connecting the micro-gap discharge tube 41 to the sub-circuit 44.

Table 3 shows the test results for the configuration according to this example.

The substrate material was Bakelite, and the temperature fuse used was 7A, operating at 115°C.

■ From the results in Table 3, when continuous overvoltage and overcurrent are applied to the micro gear knob type discharge tube, the temperature fuse blows out in about 10 to 30 seconds without causing any smoke or ignition of the board.1. @It is clear that the overvoltage and overcurrent have been cut off.

[Example 3] This will be explained with reference to FIGS. 3A and CB). This structure uses two temperature fuses installed in parallel in close contact with the surge absorbing element, eliminating the polarity of the lead wires.

One lead wire portion 52 of the microgap discharge tube 51
After connecting the lead wire portions 57 and 58 of the temperature fuses 53 and 54 with the caulking 55, the two temperature fuses 53 and 54 are brought into close contact with the discharge tube 51 and fixed with stainless steel wires 56. be. These two temperature fuses 53 and 54 are provided symmetrically with respect to the surge absorbing element 51, and when connected to the power supply side and the electronic circuit (equipment) side, the polarity must be changed. I don't have it.

FIG. 3B shows the installation circuit. When a continuous overvoltage/overcurrent is detected from the power source 1/source 64, first, the discharge tube 61 generates heat, but due to the heat generation.

At the same time as the temperature fuses 62 and 63 melt and blow, and the general overvoltage and overcurrent applied to the discharge tube 61 is cut off, continuous overvoltage and overcurrent may be applied to the electronic circuit (equipment). It is prevented. In this embodiment, even if the thermal fuse 63 connected to the electronic circuit 65 blows out first, the overvoltage continues to flow through the thermal fuse 62 connected to the power supply 64! The continuous overvoltage and overcurrent can only be interrupted when a current of 4 is applied to the discharge tube 61 and the temperature fuse 62 is finally fused.

[Comparative Example] The results of applying an N-controlled overcurrent flow 1 to the surge absorption elements of a gap type discharge tube and a microgap type discharge tube were observed. A continuous overcurrent specific pressure flow load test was conducted on a gap type discharge tube and a microgap type discharge tube using Bakelite as the substrate material, with an applied voltage of 300 VAC and a current of 900 mA. In 55 seconds, the board caught fire.

1 Sat 1 Even if the current value is so small that it will not blow even a 3A fuse, which is common in general equipment, if it is continuously applied to the surge absorbing element, the surge absorbing element will heat up in several tens of seconds to several minutes. , there is a risk that the board will also catch fire.

[Effects of the Invention] The surge absorbing element of the present invention has a configuration in which a temperature fuse is installed closely on the surface of the surge absorbing element and is electrically connected in series to both the absorbing element and an electronic circuit (m unit). As a result, firstly, the surge absorption element can be protected when overvoltage and overcurrent are applied to the absorption element, thereby providing a surge absorption element that prevents the danger of smoke and ignition due to continuous overvoltage, etc. , vJ2, while protecting the surge absorbing element from continuous overvoltage and overcurrent! Thirdly, we were able to provide a surge absorption element that can cut off the lead wire circuit for the M-meter circuit and protect the T-voltage circuit itself, and thirdly, we have created a safe surge that is protected from over-voltage and over-current loads of 1M. Fourth, technical effects such as being able to provide an absorption element circuit and, at the same time, being able to provide a surge absorption element equipped with a means for protecting equipment circuits from overvoltage energization (circle) were obtained.

[Brief explanation of drawings]

1A and 18 are a sectional view showing the structure of one example of the surge absorbing element of the present invention, and a diagram showing an installation circuit. Figures 2A and 2B are a sectional view showing the structure of an example of the surge absorbing element of the present invention, and a diagram showing the circuit for mounting. Figures 3A and 3B show an embodiment of the surge absorbing element of the present invention, using two temperature fuses installed in parallel and in close contact with the absorbing element. FIG. 1 is a cross-sectional view showing the structure of a micro-gap discharge tube without lead wire polarity, and a diagram showing an installation circuit. [Explanation of symbols of main parts 11.21, , Gap type discharge tube 12.12',
14,14 ° 39. Lead. 13.22 ,,ff 1 degree fuse tS, ,,caulking 16. ,,Stainless wire 23, ,It source 24, ,Electronic circuit (or equipment) 31.41 ,,Microgap discharge tube 32.
32°, 34, 34°61. Lead. 33.42 , Temperature fuse 35 , Crimping 36. ,, stainless steel wire 43,
,,Power supply 44, ,Electronic circuit (or equipment) 51.61 ,,Microgap discharge tube 52.
57.58. ,, Lead. 53.54,62,63. ,,temperature fuse 55,,,
Caulk 36. ,,stainless steel wire 64,,,power supply
65. ,, Equipment circuit patent applicant Mitsubishi Mining and Cement Co., Ltd. Agent Patent attorney Hiroshi Kuramochi (1 other person) Figure 1A Figure 18 Figure 3A Yo IB Commissioner of the Patent Office Kuro 1) Mr. Yu Akira
(Route 71U)
taTMA ``Address as above 5-1 Marunouchi-chome, Chiyoda-ku, Tokyo ``Mitsubishi Mining Cement Co., Ltd. (4) Representative Masaya Fujimura 5 seconds] 4, Agent address 1, Kanda-Suda-cho, Chiyoda-ku, Tokyo 101 2-5, correct the [operating voltage] in the second line of page 2 of the description of the contents of the invention that increases due to the amendment to [times]. Correct it to [Filling pressure]. Correct [melting and C to C in the first line from the bottom of page 4. Correct [4] in the fourth column of 34!J in Table 4 on page 20. [55
[Seconds]].

Claims (1)

[Claims] A thermal fuse is installed in close contact with the surface of the surge absorbing element, and the thermal fuse is connected in series to both the surge absorbing element and the equipment circuit to be protected by the surge absorbing element. A surge absorption element that protects both the equipment circuitry and the absorption element against continuous overvoltage and overcurrent loads.