KR102496388B1 - Fuse circuit, fuse adjusting circuit, fuse adjusting method, program and recording medium - Google Patents

Abstract

The fuse is cut off at a desired current value regardless of the rated current of the fuse element.
The fuse element is a heating resistor 33 that adjusts the heating amount of the soluble conductors 31 and 32 that are cut by a predetermined current, the soluble conductors 31 and 32, and the heating amount of the soluble conductors 31 and 32 Using the first heat generating resistor 33 for adjusting the cooling element 34 for adjusting the cooling amount of the soluble conductors 31 and 32, the first FET 23 and the second FET 24, 1 IC 22 for controlling the current interruption characteristics of the soluble conductors 31 and 32 by controlling the heating resistor 33 or the cooling element 34 is provided. The IC 22 detects a current value using the detection resistor 21 and inputs a pulse signal with an adjusted duty ratio to the first FET 23 or the second FET 24 according to the current value.

Description

Fuse circuit, fuse adjustment circuit, fuse adjustment method, program and recording medium

The present invention relates to a fuse circuit serving as a protection circuit, and more particularly, to a fuse circuit capable of adjusting the current blocking characteristics of a fuse element, a fuse adjustment circuit, and a fuse adjustment method. This application claims priority on the basis of Japanese Patent Application No. 2014-114597 for which it applied in Japan on June 3, 2014, and this application is incorporated into this application by being referred.

Most of the secondary batteries that can be charged and used repeatedly are processed into battery packs and provided to users. In particular, in lithium ion secondary batteries with high gravimetric energy density, in order to ensure the safety of users and electronic devices, several protection circuits such as overcharge protection and overdischarge protection are generally built into the battery pack, and in certain cases, the battery pack It has the function of blocking the output of

In this type of protection circuit, there is one that performs overcharge protection or overdischarge protection operation of the battery pack by turning ON/OFF the output using a FET (Field Effect Transistor) switch incorporated in the battery pack. However, if the FET switch is short-circuited or destroyed for any reason, if a lightning surge is applied and a large current flows instantaneously, or if the output voltage drops significantly due to the life of the battery cell, or if an excessive abnormal voltage is output Even so, battery packs and electronic devices must be protected from accidents such as ignition. Therefore, in order to safely cut off the output of the battery cell in any conceivable abnormal state, a protection circuit including a fuse element having a function of cutting off a current path by an external signal is used.

As a protection element of a protection circuit suitable for such a lithium ion secondary battery or the like, as described in Patent Document 1, a soluble conductor is connected between the first electrode on the current path, the conductor layer connected to the heating element, and the second electrode to form a current path There is a case where a part of is removed and the soluble conductor on this current path is cut by self-heating due to overcurrent or by a heating element provided inside the protection element. In such a protection element, a current path is blocked by concentrating a soluble conductor in a molten liquid state on a conductor layer connected to a heating element.

Japanese Unexamined Patent Publication No. 2005-206220

Recently, EVs (Electric Vehicles) and HEVs (Hybrid Electric Vehicles) using batteries and motors are rapidly spreading. As a power source for HEVs and EVs, lithium ion secondary batteries are being used because of their energy density and output characteristics. For automobile applications, high voltage and large current are required. In addition, products requiring high voltage and large current, such as cordless power tools and electric assist bicycles, are also increasing. In connection with this, a product corresponding to a large current is also desired for the fuse element used for the protection circuit.

However, in a fuse element, when an excessive current flows, the fusible conductor that is the fuse element generates self-heating and is cut by melting, so that the fusible conductor having a higher rated current corresponding to the large current has a larger volume at the fusing portion, and thus requires more time for fusing. will do

Specifically, in the case of using a soluble conductor of the same material, when the rated current (hereinafter also referred to as an energized current) becomes large, the melting time tends to be long and the breaking characteristic deteriorates. For this reason, the fuse element using the soluble conductor for large current has the subject that the time to cut off a circuit becomes long, when an overcurrent flows, and it is difficult to break a circuit quickly.

In addition, in device design, when the characteristics of current and fusing time that can be passed to the device to be protected do not match the interruption characteristics of the soluble conductor, it is required to respond by lowering the rated current of the fuse element.

However, when the rated current of the fuse element is lowered, the resistance value of the fusible conductor becomes high, the energy loss increases, and a current exceeding the rated current momentarily flows, such as a small surge rather than a large current equivalent to a lightning surge. It has the subject that a soluble conductor is cut by melting even in the safe energization time which does not cause a failure of an apparatus only, and it becomes difficult to continue use of an apparatus.

An object of the present invention is to solve the above problems, and to provide a fuse circuit, a fuse adjusting circuit, and a fuse adjusting method capable of rapidly cutting a soluble conductor even in a fuse element having a large rated current.

In order to solve the above problems, the fuse circuit according to the present invention is a soluble conductor that is cut by a predetermined current, a temperature controller for adjusting the amount of heating or cooling of the soluble conductor, and a soluble conductor by controlling the temperature controller It is provided with a control unit for controlling the current blocking characteristics of.

In addition, the fuse adjustment circuit according to the present invention is connected to the temperature control unit and the temperature control unit for adjusting the amount of heating or cooling of the soluble conductor to be cut by a predetermined current, and controls the current applied to the temperature control unit By doing so, it is provided with a control unit for controlling the current blocking characteristics of the soluble conductor.

In addition, the fuse adjusting method according to the present invention controls the current cutoff characteristics of the soluble conductor by controlling the current applied to the temperature controller for adjusting the amount of heating or cooling of the soluble conductor to be cut by a predetermined current.

In addition, the program according to the present invention controls the current applied to the temperature control unit for adjusting the heating or cooling amount of the soluble conductor to be cut by a predetermined current to the computer, thereby controlling the current blocking characteristics of the soluble conductor The processing is executed, and the recording medium according to the present invention has this program recorded thereon.

According to the present invention, it is possible to adjust the melting time of the soluble conductor determined by the rated current of the fuse element, and the soluble conductor can be quickly cut even in a fuse element having a large rated current, and the rated current is also It is possible to select the fuse element without lowering the current.

1 is a circuit diagram illustrating a fuse circuit;
2 is a graph illustrating current blocking characteristics of a fuse element.
3 is a graph illustrating a change in a duty ratio of a pulse signal;
4 is a graph illustrating a change in a duty ratio of a pulse signal;
Fig. 5 is a circuit diagram explaining another fuse circuit;
Fig. 6 is a circuit diagram explaining another fuse circuit;
Fig. 7 is a block diagram explaining the configuration of a computer that executes processing;
8 is a flowchart illustrating a program executed by a computer and a fuse adjustment method;
9 is a graph showing evaluation results of Example 1;
10 is a graph showing evaluation results of Example 2;
11 is a graph showing evaluation results of Example 3;

Hereinafter, a fuse circuit, a fuse adjustment circuit, a fuse adjustment method, a program, and a recording medium to which the present invention is applied will be described in detail with reference to the drawings. In addition, this invention is not limited only to the following embodiment, Of course, various changes are possible within the range which does not deviate from the summary of this invention. In addition, drawings are typical, and the ratio of each dimension may differ from an actual thing. Specific dimensions and the like should be judged in consideration of the following description. In addition, it goes without saying that even between the drawings, there are portions in which the relationship or ratio of dimensions to each other is different.

Hereinafter, as shown in FIG. 1 , a battery unit 1 in which a plurality of cells of a lithium ion battery 11 are arranged in series will be described as an example.

The battery unit 1 includes a lithium ion battery 11 and a fuse circuit 12 serving as its protection circuit. The lithium ion battery 11 and the fuse circuit 12 are arranged in series. The fuse circuit 12 operates to cut off the lithium ion battery 11 from external devices of the battery unit 1 when an excessive current flows. In addition, in this example, it is not limited to a lithium ion battery, and various batteries capable of outputting a large current may be used.

[Example 1 of fuse circuit]

The fuse circuit 12 includes a detection resistor 21 connected in series with the lithium ion battery 11, an IC (Integrated Circuit) 22 connected in parallel to both ends of the detection resistor 21, and an IC ( 22) and the first FET (field effect transistor) 23 and the second FET 24 connected, the detection resistor 21, the first FET 23 and the second FET 24 and a protection element connected ( 25) is composed of

In the fuse circuit 12, the IC 22 detects a current value output from the lithium ion battery 11 using the detection resistor 21, and based on the current value detected by the IC 22, a first FET ( 23) and the second FET 24, the protection element 25 is operated, and the output circuit of the lithium ion battery 11 is cut off.

The detection resistor 21 is an electrical resistance for monitoring the current on the output circuit of the lithium ion battery 11 by the IC 22, and has a resistance value so that a large current exceeding the rated current of the protection element 25 can be detected. is set.

The IC 22 is a control unit with a built-in program that monitors the current on the output circuit of the lithium ion battery 11 and operates the first FET 23 and the second FET 24 based on the detected current value. Further, the IC 22 may be operated by a computer program instead of a built-in integrated circuit. Details of the example of the program will be described later.

The first FET 23 and the second FET 24 are switch elements that control the current flowing to the temperature controller inside the protection element 25 . The first FET 23 and the second FET 24 are configured to operate based on signals input from the IC 22 . Regarding the temperature controller, the details of the configuration of the protection element 25 will be described.

The protection element 25 is a first heat generating resistor connected to the first soluble conductor 31 and the second soluble conductor 32 arranged in series on the output circuit of the lithium ion battery 11 and the first FET 23 (33) and a cooling element (34) connected to the second FET (24).

The 1st soluble conductor 31 contains the low-melting-point metal which melts quickly by heat_generation|fever of the 1st heat generating resistor 33, For example, Pb free solder which has Sn as a main component can be used suitably.

Like the first soluble conductor 31, the second soluble conductor 32 contains a low melting point metal that is quickly melted by heat generated by the first heat generating resistor 33, for example, a Pb-free material containing Sn as a main component. Solder can be used appropriately.

In addition, when using the same material, the 1st soluble conductor 31 and the 2nd soluble conductor 32 can be integrally molded. In this case, since the 1st soluble conductor 31 and the 2nd soluble conductor 32 can be made into one fuse element, the number of parts of protection element 25 can be reduced. In addition, it goes without saying that the 1st soluble conductor 31 and the 2nd soluble conductor 32 can be made of mutually different materials.

The 1st heat generating resistor 33 constitutes a temperature control part, and is a resistance part which is arrange|positioned so that it may thermally contact the 1st soluble conductor 31 and the 2nd soluble conductor 32 on the insulating substrate not shown. The first heating resistor 33 generates heat by resistance when current flows, and can heat the first soluble conductor 31 and the second soluble conductor 32 .

The cooling element 34 is an electrical cooling component that constitutes a temperature control unit, is on an insulating substrate (not shown), and is disposed so as to thermally contact the first soluble conductor 31 and the second soluble conductor 32 . The cooling element 34 is an element capable of absorbing heat, that is, cooling, by passing an electric current, such as a Pelche element, for example. When current flows, the cooling element 34 may cool the first soluble conductor 31 and the second soluble conductor 32 that are in thermal contact with each other.

Here, the protection element 25 is a third terminal connecting the first terminal a and the second terminal b serving as the output path of the lithium ion battery 11 and the first FET 23 and the first heating resistor 33 It is a four-terminal element including c and a fourth terminal d connecting the second FET 24 and the cooling element 34. The first soluble conductor 31, the second soluble conductor 32, the first heat generating resistor 33, and the cooling element 34 each have one end at a first terminal a, a second terminal b, a third terminal c, and a second terminal. 4 It is connected to terminal d, and the other end is connected to the center of the circuit.

In the protection element 25, when an excessive current flows, the first soluble conductor 31 and the second soluble conductor 32 generate heat due to their resistance, and the first FET 23 is controlled by the IC 22. When ) is turned ON, current flows through the first heat generating resistor 33, and the first soluble conductor 31 and the second soluble conductor 32 are heated.

On the other hand, in the protection element 25, when an excessive current flows, the first soluble conductor 31 and the second soluble conductor 32 generate heat due to their resistance, and the second FET is controlled by the IC 22. By (24) being turned ON, an electric current flows through the cooling element 34, and the 1st soluble conductor 31 and the 2nd soluble conductor 32 are cooled.

Here, the fusing time (s) of the 1st soluble conductor 31 which is a fuse element, and the 2nd soluble conductor 32 is demonstrated simply using FIG.

The cutting time (s) of the first soluble conductor 31 and the second soluble conductor 32 as a reference may be represented by a curve of L1, as shown in the upper graph of FIG. 2 . On the other hand, as shown in the upper graph of FIG. 2, the melting time (s) of the fuse element having a smaller rated current than the first soluble conductor 31 and the second soluble conductor 32, the current blocking characteristic is represented by the curve of L2 can On the other hand, as shown in the upper graph of FIG. 2, the melting time (s) of the fuse element having a smaller rated current than the first soluble conductor 31 and the second soluble conductor 32, the current interruption characteristic is represented by the curve L3 can

In this way, as shown in the upper graph of FIG. 2 , the melting time of the fuse element shifts to the left as the rated current decreases, and shifts to the right as the rated current increases.

Next, when the 1st heating resistor 33 of the protection element 25 is actuated, it demonstrates using FIG. 2 about the fusing time (s) of the 1st soluble conductor 31 and the 2nd soluble conductor 32 do.

As shown in the lower graph of FIG. 2, the self-heating amount of the 1st soluble conductor 31 and the 2nd soluble conductor 32 has a characteristic like the curve H1 which increases with the increase of electric current. On the other hand, the first heating resistor 33 controls the first FET 23 to generate the most heat at a predetermined current value, for example, I1, and gradually reduces the amount of heat generated as the current value increases, so that the current It has the same characteristics as curve H2, where the calorific value becomes zero at I2. That is, the control of the first FET 23 of the IC 22 gives the same characteristic as the curve H2.

When the control of passing the current through the first heat generating resistor 33 is performed, the total heat generated by the protection element 25 is the heat generated by the first soluble conductor 31 and the second soluble conductor 32, and the first heat generating resistor ( 33), the calorific values are synthesized, and the characteristics are approximately the same as those of the curve H1'. In addition, although the calorific value of the first heating resistor 33 can be arbitrarily set by the control of the IC 22, by setting it to the same characteristic as the curve H2, the first soluble conductor 31 and the second soluble conductor 32 described later The current cut-off characteristic becomes optimal.

When the calorific value of the first heating resistor 33 is set to the same characteristic as the curve H2 by the control of the IC 22, preliminary overheating starts at I1 where the current value is smaller than the rated current and the heat amount is applied, so that the first available The current interruption characteristics of the conductor 31 and the second soluble conductor 32 change like a curve indicated by L1' in which the fusing start current is shifted to the left so as to cut even at a current I1 equal to or less than the rated current.

That is, by controlling the current supplied to the first heating resistor 33 by controlling the first FET 23 by the IC 22, the current of the first soluble conductor 31 and the second soluble conductor 32 The breaking characteristic can be shifted to the curve L2 side of the fuse element having a small rated current.

Thereby, not only the 1st soluble conductor 31 and the 2nd soluble conductor 32 can be cut by melting below a rated current, but also it becomes possible to shorten the melting time.

For example, when compared at the cutting time T3, it can be seen that the heated L1' cuts with a smaller current than the non-heated L1. Comparing at the time T2 shorter than the fusing time T3, it can be seen that similarly, the heated L1' cuts with a smaller current than the non-heated L1.

However, when compared at a time T1 shorter than the fusing time T2, the difference is hardly seen. That is, when a large current flows like I2, there is no difference in the short fusing time T1, and the current cut-off characteristics of the first soluble conductor 31 and the second soluble conductor 32 are maintained, and the current value is smaller than I2 and I1 It can be said that the reduction of the fusing time is achieved in a larger range.

Next, when the cooling element 34 of the protection element 25 is actuated, the fusing time s of the 1st soluble conductor 31 and the 2nd soluble conductor 32 is demonstrated using FIG.

As shown in the lower graph of FIG. 2, the self-heating amount of the 1st soluble conductor 31 and the 2nd soluble conductor 32 has a characteristic like the curve H1 which increases with the increase of electric current. In contrast, the cooling element 34, for example, sets a predetermined current value as I3, controls the second FET 24 so as to be most cooled at this time, and gradually reduces the amount of heat (cooling) as the current value increases. It has the same characteristics as curve H3 where the current value becomes zero at I4. That is, the control of the second FET 24 of the IC 22 gives the same characteristic as the curve H3.

When control is performed to pass an electric current through the cooling element 34, the total calorific value as the protection element 25 is the calorific value of the first soluble conductor 31 and the second soluble conductor 32 and the calorific value of the cooling element 34 (cooling) is synthesized, resulting in characteristics similar to those of curve H1". Further, the amount of heat generated (cooling) of cooling element 34 can be arbitrarily set by the control of IC 22, but by setting characteristics similar to those of curve H3, The current interruption characteristics of the first soluble conductor 31 and the second soluble conductor 32 described later become optimal.

When the calorific value (cooling) of the cooling element 34 is controlled by the IC 22 to have the same characteristics as the curve H3, since cooling starts from around the rated current, the first soluble conductor 31 and the second soluble conductor The current interruption characteristic of (32) changes like a curve indicated by L1" shifted to the right so that the fusing time becomes longer from the current I3 near the rated current to the current I4.

That is, the current supplied to the cooling element 34 is controlled by the control of the second FET 24 by the IC 22, and the current blocking characteristics of the first soluble conductor 31 and the second soluble conductor 32 can be shifted to the curve L3 side of the fuse element having a large rated current.

In this way, it is possible to take a longer time to cut the first soluble conductor 31 and the second soluble conductor 32 at a current greater than the rated current, and the first soluble conductor 31 and the first soluble conductor 31 and It can suppress that the 2nd soluble conductor 32 cut by melting.

For example, when compared at the fusing time T3, it can be seen that the L1″ that is heated rather than the uncooled L1 cuts with a larger current. When compared at the time T2 shorter than the fusing time T3, it is similarly heated more than the uncooled L1. It can be seen that one L1" melts at a large current. Comparing with the time T1 shorter than the melting time T2, similarly, it can be seen that the heated L1" cuts with a larger current than the uncooled L1. That is, the cooling element 34 cools the first soluble conductor It can be said that the current interruption characteristics of (31) and the second soluble conductor 32 are adjusted to a higher rated current.

Next, the signal for the IC 22 to control the first FET 23 will be briefly described using FIGS. 3 and 4 .

The IC 22 controls the first FET 23 using a pulse signal. That is, the IC 22 controls the current flowing through the first heating resistor 33 by controlling the ON/OFF of the first FET 23 by adjusting the pulse duty ratio, which is the ON/OFF ratio of the pulse signal. .

Specifically, as shown in FIG. 3, the IC 22 outputs a pulse signal having a duty ratio of 50% to the first FET 23 when the detected current value exceeds I1. Then, the IC 22 outputs a pulse signal to the first FET 23 so as to continuously and gradually lower the duty ratio until the detected current value reaches I2. Finally, when the detected current value reaches I2, the IC 22 sets the duty ratio to 0, that is, does not output a pulse signal to the first FET 23.

As described above, by outputting the pulse signal to the first FET 23, a current flows through the first heat generating resistor 33 according to the duty ratio, so that the amount of heat indicated by the curve H2 shown in the lower graph of FIG. 2 becomes the first It can be added to the soluble conductor 31 and the 2nd soluble conductor 32.

In addition, as shown in FIG. 4, when the detected current value exceeds I1, the IC 22 outputs a pulse signal with a duty ratio of 50% to the first FET 23, and the IC 22 detects A pulse signal may be output to the first FET 23 so as to lower the duty ratio step by step until one current value reaches I2, and when the detected current value reaches I2, the duty ratio may be set to 0. That is, in order to obtain a desired current blocking characteristic, it is only necessary to control the amount of heat generated by the first heating resistor 33 .

Next, the IC 22 controls the second FET 24 will be briefly explained.

The IC 22 controls the second FET 24 using a pulse signal. That is, the IC 22 controls the current flowing through the cooling element 34 by controlling the ON/OFF of the second FET 24 by adjusting the pulse duty ratio, which is the ON/OFF ratio of the pulse signal.

As described above, by outputting the pulse signal to the second FET 24, current flows through the cooling element 34 according to the duty ratio, so the amount of heat (cooling) shown in the curve H3 shown in the lower graph of FIG. 2 is removed. It can add to 1 soluble conductor 31 and the 2nd soluble conductor 32. In addition, since specific control can be set similarly to the signal which controls the 1st FET 23, detailed description is abbreviate|omitted.

Here, the detection resistor 21 and the IC 22 constitute the fuse adjustment circuit 20 as shown in FIG. That is, in this configuration, the fuse adjustment circuit is arranged in series between the protection element 25 and the lithium ion battery 11 . The fuse adjustment circuit 20 performs heating by the 1st heating resistor 33 by turning on the 1st FET 23, and cools by turning on the 2nd FET 24, so that the 1st soluble conductor 31 And it is possible to adjust the amount of heating for the second soluble conductor 32, the first soluble conductor 31 and the second soluble conductor 32, it operates so as to obtain an arbitrary current blocking characteristic.

[Example 2 of fuse circuit]

Next, the fuse circuit 1 of another structure is demonstrated using FIG. In addition, in this example, the same code|symbol is attached|subjected to the structure substantially equivalent to the structure of FIG. 1, and description is abbreviate|omitted.

This example is a configuration in which an external heater is used without incorporating a temperature controller like the protection element 25. Specifically, the fuse circuit 12 includes a detection resistor 21 connected in series with the lithium ion battery 11, an IC (integrated circuit) 22 connected in parallel to both ends of the detection resistor 21, and lithium A third fusible conductor (41) connected in series with the ion battery (11), a second heating resistor (42) arranged to be thermally connected to the third fusible conductor (41), an IC (22) and a second heating It is composed of a third FET 43 connected to a resistor 42.

The fuse circuit 12 shown in FIG. 5 has a simple fuse configuration including only the third fusible conductor 41 without using a special element such as a protection element 25 incorporating a heater as a temperature control unit, It has a configuration in which the second heat generating resistor 42 having a set resistance value is added as a temperature control unit, and is highly versatile and easy to handle because the resistance value can be freely changed according to the use.

[Example 3 of fuse circuit]

Next, the fuse circuit 1 of another structure is demonstrated using FIG. Note that, in this example, the same reference numerals are assigned to substantially the same configurations as those in FIGS. 1 and 5, and descriptions thereof are omitted.

This example is a configuration in which an external heater is used without incorporating a temperature controller like the protection element 25. Specifically, the fuse circuit 12 includes a detection resistor 21 connected in series with the lithium ion battery 11, an IC (Integrated Circuit) 22 connected in parallel to both ends of the detection resistor 21, and lithium ion A third soluble conductor (41) connected in series with the battery (11), a second heating resistor (42) arranged to be thermally connected to the third soluble conductor (41), an IC (22) and a second heating resistor The third FET 43 connected to (42), the third heat generating resistor 44 arranged to be thermally connected to the third soluble conductor 41, the IC 22 and the third heat generating resistor 44, It is constituted by a connected fourth FET 45.

The fuse circuit 12 shown in FIG. 5 has a simple fuse configuration including only the third fusible conductor 41 without using a special element such as a protection element 25 incorporating a heater as a temperature control unit, It is a configuration in which the second heating resistor 42 and the third heating resistor 44 with set resistance values are added as temperature controllers, and is highly versatile and excellent in that each resistance value can be freely changed according to the application. .

In addition, it is preferable that the second heat generating resistor 42 and the third heat generating resistor 44 have different resistance values. The amount of heat generated can be adjusted by a combination of heat generating resistors, for example, when only the second heat generating resistor 42 is operated and when only the third heat generating resistor 44 is operated, the second heat generating resistor 42 and the second heat generating resistor 42 are operated. 3 When operating both heating resistors 44, even when the same pulse signal is output from the IC 22, the amount of heat generated is different, so by increasing the number of heating resistors, a more complex current cut-off in combination with IC pulse signal control properties can be obtained.

In addition, in the present invention, it is not limited to the configuration of the fuse circuit as shown in the above-described FIGS. 1, 5 and 6, and a plurality of heating resistors and cooling elements can be suitably combined as a temperature control unit. needless to say

[IC Control and Program]

Fig. 7 is a block diagram showing a configuration in the case where functions of the IC 22 according to the present embodiment are executed by a computer program. This program may be built into the IC 22 or may be controlled using an external computer resource.

As shown in FIG. 7, the computer 100 includes a CPU (Central Processing Unit) 101 that performs program execution processing, and a ROM (Read Only) that stores programs executed by the CPU 101. It is composed of a Memory (read-only memory) 102 and a RAM (Random Access Memory) 103 that develops programs or data, and is configured to control each FET through an interface.

The CPU 101 controls the operation of each block of the computer 100. Specifically, the CPU 101 controls the operation of each block by, for example, reading a program for adjusting a fuse recorded in the ROM 102, deploying the program to the RAM 103, and executing the program.

The ROM 102 is, for example, a rewritable non-volatile memory, and the RAM 103 is a volatile memory.

Next, the process of adjusting the fuse executed in the computer 100 will be described concretely using the flowchart of FIG. 8 . The processing corresponding to this flowchart can be realized by the CPU 101 reading, for example, a corresponding processing program recorded in the ROM 102, developing it into the RAM 103, and executing it.

In step S101, the CPU 101 measures current values from both ends of the detected resistance value 21, and advances the process to step S102.

In step S102, the CPU 101 determines whether or not the measured current value is larger than a predetermined value. Here, the predetermined value is, for example, I1 shown in FIG. 2 . When the CPU 101 determines that the measured current value is greater than the predetermined value, the process proceeds to step S103, and when it is determined that the measured current value is equal to or less than the predetermined value, the process of step S101 is repeated.

In step S103, the CPU 101 outputs a pulse signal corresponding to the measured current value to each FET. As for the pulse signal to be output, a pulse signal obtained by adjusting the various duty ratios described above can be used.

In step S104, the CPU 101 measures current values from both ends of the detected resistance value 21, and counts up the timer counter. Here, the current value is measured because the pulse signal according to the current value is output in step S103 described above.

In step S105, the CPU 101 judges whether the measured current value is 0 or whether the count value of the timer counter has reached a predetermined time. When the CPU 101 judges that the measured current value is 0, the process proceeds to step S106, and when it judges that the measured current value is not 0, it returns to step S103 and repeats the process. Further, when the CPU 101 determines that the count value of the timer counter has reached the predetermined time, the processing proceeds to step S106, and when it is judged that the count value of the timer counter has not reached the predetermined time, the processing proceeds to step S103. Go back and repeat the process.

In step S106, the CPU 101 stops the output of the pulse signal to each FET or performs a process of setting the pulse duty ratio to 0%, and ends this process.

[Example]

Hereinafter, embodiments of the present invention will be described. In this embodiment, the current interruption characteristics of the fuse element were evaluated by adjusting the temperature controller. In addition, this invention is not limited to these Examples.

[Example 1]

As a protection element, the test was done using the built-in heater fuse (SFK-30A: made by Decceria Rouge). The rated current of the protection element was 30 A, the resistance value of the heater was 50.0 Ω, the battery voltage was 40 V, and the current passing through the protection element was evaluated in four stages of 30 A, 60 A, 80 A, and 100 A.

As the evaluation results, as shown in Table 1 and FIG. 9, when heating with a heater was not applied to the protection element for a rated current of 30 A, the fuse element did not melt and no circuit breakage was confirmed. When a pulse signal with a duty ratio of 50% was applied to the protection element and heating of 16 W was applied by a heater, the circuit was disconnected in 4.0 seconds even at a rated current of 30 A.

Next, in the case where heating by a heater was not applied to the protection element for a current of 60 A exceeding the rated current, circuit disconnection was performed at 15.0 seconds. When a pulse signal with a duty ratio of 50% was applied to the protection element and heating of 16 W was applied by a heater, the circuit was disconnected in 1.7 seconds.

Next, when heating with a heater was not applied to the protection element for a current of 80 A exceeding the rated current, circuit disconnection was performed in 3.0 seconds. When a pulse signal with a duty ratio of 30% was applied to the protection element and heating of 10 W was applied by a heater, the circuit was disconnected in 1.0 seconds.

Next, when heating with a heater was not applied to the protection element for a current of 100 A exceeding the rated current, circuit disconnection was performed in 0.8 seconds. In addition, a pulse signal was not passed through the protection element for a current of 100 A.

As described above, in Example 1, it is understood that the melting time of the fuse element can be arbitrarily controlled by applying heating by a pulse signal to the protection element. In particular, while the effect of shortening the melting time due to overheating was remarkable, it became possible to cut the fuse element even at a rated current.

[Example 2]

As the protection element, a test was conducted using a non-heater-equipped fuse (SFK-30A: manufactured by Decceria Rouge Co., Ltd.). The rated current of the protection element is 30A, the heating resistor R1 with a resistance value of 19Ω and the heating resistor R2 with a resistance value of 26Ω are used as heaters outside the protection element, the battery voltage is set to 12V, and the current flowing through the protection element is, Evaluation was performed in four stages of 30A, 60A, 80A, and 100A. In addition, the external heater and the fuse element in the protection element are configured to be thermally connected.

As for the evaluation results, as shown in Table 2 and FIG. 10, in the case where heating by a heater is not applied to the protection element for a current of 30 A, which is a rated current, the fuse element does not melt and no circuit breakage is confirmed. A total of 13.1 W of heating was applied by passing current to both the heat generating resistor R1 and the heat generating resistor R2, and the circuit was disconnected in 18.0 seconds even at a rated current of 30 A.

Next, in the case where heating by a heater was not applied to the protection element for a current of 60 A exceeding the rated current, circuit disconnection was performed at 15.0 seconds. When a current was applied only to the heating resistor R1 and heating of 7.6 W was applied by a heater, the circuit was disconnected in 8.0 seconds.

Next, when heating with a heater was not applied to the protection element for a current of 80 A exceeding the rated current, circuit disconnection was performed in 3.0 seconds. When a current was applied only to the heating resistor R2 and heating of 5.5 W was applied by a heater, the circuit was disconnected in 2.0 seconds.

Next, when heating with a heater was not applied to the protection element for a current of 100 A exceeding the rated current, circuit disconnection was performed in 0.8 seconds. In addition, about the 100 A current, heating by the heater was not carried out to the protection element.

As described above, in Example 2, by using a plurality of external heaters having different resistance values and heating the protection element, it is understood that the melting time of the fuse element can be arbitrarily controlled according to the combination of resistance values. In particular, while the effect of shortening the melting time due to overheating was remarkable, it became possible to cut the fuse element even at a rated current.

[Example 3]

As a protection element, the test was done using the built-in heater fuse (SFK-30A: made by Decceria Rouge). The rated current of the protection element was 30 A, the resistance value of the heater was 50.0 Ω, the battery voltage was 40 V, and the current passing through the protection element was evaluated in four stages of 29 A, 30 A, 60 A, and 80 A.

As for the evaluation results, as shown in Table 3 and FIG. 11, when heating with a heater was not applied to the protection element for a current of 29 A below the rated current, the fuse element did not melt and no circuit breakage was confirmed. When a pulse signal having a duty ratio of 0% was applied to the protection element and heating of 0 W was applied by a heater, circuit breakage was not confirmed.

Subsequently, when heating with a heater was not applied to the protection element for a current of 30 A, which is a rated current, the fuse element did not melt and no circuit breakage was confirmed. When a pulse signal with a duty ratio of 50% was applied to the protection element and heating of 16 W was applied by a heater, the circuit was disconnected in 4.0 seconds even at a rated current of 30 A.

Next, in the case where heating by a heater was not applied to the protection element for a current of 60 A exceeding the rated current, circuit disconnection was performed at 15.0 seconds. When a pulse signal with a duty ratio of 50% was applied to the protection element and heating of 16 W was applied by a heater, the circuit was disconnected in 1.7 seconds.

Next, when heating with a heater was not applied to the protection element for a current of 80 A exceeding the rated current, circuit disconnection was performed in 3.0 seconds. When a pulse signal with a duty ratio of 30% was applied to the protection element and heating of 10 W was applied by a heater, the circuit was disconnected in 1.0 seconds.

As described above, in Example 3, it is understood that the melting time of the fuse element can be arbitrarily controlled by applying heating by a pulse signal to the protection element. In particular, as can be seen from the comparison between 29A and 30A, it became possible to control the melting of the fuse element even in units of 1A. Specifically, by not heating with a heater or by applying cooling, the fuse element can be adjusted not to melt at 29A, and by heating with a heater and not cooling, arbitrary characteristics can be obtained at 30A. can be realized.

As described above, by using the fuse adjusting circuit according to the example of the present invention, it is possible to break the circuit even at a current lower than the rated current of the fuse element, and when it is desired to break the circuit at a current less than the rated current, the fuse It becomes possible to respond without changing the rating of the element.

In addition, by using the fuse adjustment circuit according to the example of the present invention, current interruption characteristics can be arbitrarily adjusted even in a fuse element having predetermined current interruption characteristics. Thereby, even in a fuse element with a large rated current, the melting time can be shortened. In addition, depending on the application, the fusing time can be lengthened or not cut by using a cooling element.

In addition, since the fusing time can be shortened even with a current slightly exceeding a predetermined rated current by using the fuse adjusting circuit according to the example of the present invention, the circuit is cut off even in applications where the energized time is limited, such as a mobile device. it becomes possible to do

In addition, by using the fuse adjustment circuit according to the example of the present invention, it is possible to use a fuse element having a higher rated current than the rated current required in the circuit configuration of the device. In other words, since the fuse resistance value can be lowered while obtaining desired current interruption characteristics, it becomes possible to protect connected devices as a protection circuit while avoiding energy loss.

1 : Battery unit
11 : Battery
12: fuse circuit
20: fuse adjustment circuit
21: detection resistor
22: IC
23: first FET
24: second FET
25: protection element
31: first fusible conductor
32: second fusible conductor
33: first heating resistor
34: cooling element
41: third fusible conductor
42: second heating resistor
43: third FET
44: third heating resistor
45: fourth FET
100: computer
101: CPU
102: ROM
103: RAM

Claims (41)

A soluble conductor that is cut by a predetermined current;
A temperature control unit for adjusting the amount of heating or cooling of the soluble conductor;
A fuse circuit comprising a control unit for controlling a current cut-off characteristic indicating a melting time for a conduction current value of the soluble conductor by controlling the temperature control unit. According to claim 1,
The temperature control unit is a heat generating resistor or a cooling element fuse circuit. According to claim 1 or 2,
The temperature controller is a fuse circuit that is a combination of a plurality of heat generating resistors or a plurality of cooling elements or a heat generating resistor and a cooling element. According to claim 2,
The temperature control unit is composed of the heating resistor or the cooling element having different heating or cooling characteristics, respectively. According to claim 2 or 4,
The control unit adjusts the amount of heat applied to the soluble conductor by controlling a current flowing through the heating resistor or the cooling element. According to claim 3,
The control unit adjusts the amount of heat applied to the soluble conductor by controlling a current flowing through the heating resistor or the cooling element. According to claim 5,
The control unit adjusts the amount of heat applied to the soluble conductor by pulse-controlling the current flowing through the heating resistor or the cooling element. According to claim 6,
The control unit adjusts the amount of heat applied to the soluble conductor by pulse-controlling the current flowing through the heating resistor or the cooling element. According to claim 7,
The control unit has a detection resistor disposed in series with the soluble conductor, and varies a duty ratio based on a value of a current flowing through the soluble conductor. According to claim 8,
The control unit has a detection resistor disposed in series with the soluble conductor, and varies a duty ratio based on a value of a current flowing through the soluble conductor. The method of any one of claims 1, 2 and 4,
The fuse circuit according to claim 1 , wherein the control unit has a detection resistor arranged in series with the soluble conductor, and starts control of the temperature control unit when a current value flowing through the soluble conductor exceeds a predetermined value. The method of any one of claims 1, 2 and 4,
The fuse circuit according to claim 1 , wherein the controller stops control of the temperature controller when a predetermined time elapses after starting control of the temperature controller. The method of any one of claims 1, 2 and 4,
The controller has a detection resistor arranged in series with the soluble conductor, and stops control of the temperature controller when the current value flowing through the soluble conductor becomes approximately zero after starting control of the temperature controller. A temperature control unit for adjusting the amount of heating or cooling of the soluble conductor to be cut by a predetermined current;
A fuse adjustment circuit having a control unit connected to the temperature controller and controlling a current cut-off characteristic indicating a melting time for a conduction current value of the soluble conductor by controlling a current applied to the temperature controller. According to claim 14,
The temperature control unit is a heating resistor or a cooling element, the fuse adjustment circuit. The method of claim 14 or 15,
The temperature control unit is a fuse adjusting circuit that is a combination of a plurality of heat generating resistors or a plurality of cooling elements or a heat generating resistor and a cooling element. According to claim 15,
The temperature control unit is a plurality of heat generating resistors or a plurality of cooling elements or a combination of a heat generating resistor and a cooling element, and is configured with different heating or cooling characteristics. The method of claim 15 or 17,
The control unit adjusts the amount of heat applied to the soluble conductor by controlling a current flowing through the heating resistor or the cooling element. According to claim 16,
The control unit adjusts the amount of heat applied to the soluble conductor by controlling the current flowing through the heating resistor or the cooling element. According to claim 18,
The control unit adjusts the amount of heat applied to the soluble conductor by pulse-controlling the current flowing through the heating resistor or the cooling element. According to claim 19,
The control unit adjusts the amount of heat applied to the soluble conductor by pulse-controlling the current flowing through the heating resistor or the cooling element. According to claim 20,
wherein the control unit varies a duty ratio based on a current value flowing through the soluble conductor. According to claim 21,
wherein the control unit varies a duty ratio based on a current value flowing through the soluble conductor. The method of any one of claims 14, 15 and 17,
The fuse adjustment circuit in which the control unit has a detection resistor arranged in series with the soluble conductor, and starts control of the temperature control unit when a current value flowing through the soluble conductor exceeds a predetermined value. The method of any one of claims 14, 15 and 17,
The fuse adjustment circuit, wherein the controller stops control of the temperature controller when a predetermined time elapses after starting control of the temperature controller. The method of any one of claims 14, 15 and 17,
The controller has a detection resistor disposed in series with the soluble conductor, and stops control of the temperature controller when the current value flowing through the soluble conductor becomes approximately zero after control of the temperature controller is started. . A fuse adjusting method for controlling a current cutoff characteristic representing a melting time for a current value of a soluble conductor by controlling a current applied to a temperature controller that adjusts the amount of heating or cooling of a soluble conductor to be cut by a predetermined current . The method of claim 27,
The temperature control unit is a heating resistor or a cooling element. The method of claim 27 or 28,
The temperature controller is a combination of a plurality of heat generating resistors or a plurality of cooling elements or a heat generating resistor and a cooling element. According to claim 28,
The temperature control unit is a plurality of heat generating resistors or a plurality of cooling elements or a combination of a heat generating resistor and a cooling element, and is constituted by different heating or cooling characteristics. The method of claim 28 or 30,
A fuse adjustment method for adjusting the amount of heat applied to the soluble conductor by controlling the current flowing through the heating resistor or the cooling element. According to claim 29,
A fuse adjustment method for adjusting the amount of heat applied to the soluble conductor by controlling the current flowing through the heating resistor or the cooling element. According to claim 31,
A fuse adjustment method of adjusting the amount of heat applied to the soluble conductor by pulse-controlling the current flowing through the heating resistor or the cooling element. 33. The method of claim 32,
A fuse adjustment method of adjusting the amount of heat applied to the soluble conductor by pulse-controlling the current flowing through the heating resistor or the cooling element. 34. The method of claim 33,
A fuse adjusting method of varying a duty ratio based on a current value flowing through the soluble conductor. 35. The method of claim 34,
A fuse adjusting method of varying a duty ratio based on a current value flowing through the soluble conductor. The method of any one of claims 27, 28 and 30,
A fuse adjustment method comprising: detecting a current value flowing through the soluble conductor using a detection resistor arranged in series with the soluble conductor, and starting control of the temperature controller when the current value exceeds a predetermined value. The method of any one of claims 27, 28 and 30,
A fuse adjustment method of counting an elapsed time after starting control of the temperature controller, and stopping control of the temperature controller when a predetermined time elapses. The method of any one of claims 27, 28 and 30,
After starting control of the temperature controller, detecting a current value flowing through the soluble conductor using a detection resistor disposed in series with the soluble conductor, and stopping control of the temperature controller when the current value becomes approximately zero. How to adjust the fuse. on the computer,
By controlling the current applied to the temperature controller for adjusting the amount of heating or cooling of the soluble conductor to be cut by a predetermined current, the processing of controlling the current cut-off characteristic representing the melting time for the current value of the soluble conductor A program recorded on a computer-readable recording medium to be executed. A recording medium on which the program according to claim 40 is recorded.

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