JP2019068537A - Output device, protective apparatus, and setting method - Google Patents

Abstract

To provide an output device, etc. in which the range of a combination, of a current value and the duration time thereof, that halts power supply can be brought close to an inappropriate range for the combination.SOLUTION: The output device includes a high-frequency cutoff circuit that attenuates, among frequency components included in an inputted voltage indicating the value of current supplied at a fixed voltage from a power source to a load, at least one frequency component equal to or greater than a predetermined positive frequency, and outputs the attenuated frequency component, and a supply unit that, when the difference between a second voltage which is the input voltage obtained after the high-frequency cutoff circuit and a first voltage which is a fixed voltage smaller than the maximum value of the second voltage is equal to a predetermined difference, can supply, to a switch, a third voltage which can cut an electric power route between the power source and the load by means of the switch.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an apparatus for stopping power supply in certain cases.

  As the over-current protection circuit, a method is generally used in which a fuse that is cut when the specified current value is exceeded is installed on the power supply path, or a switch is cut when the voltage difference before and after the shunt resistance exceeds a threshold. It is done.

  FIG. 1 is a conceptual view showing an example of a general overcurrent protection mechanism.

  FIG. 1A shows an example of an overcurrent protection mechanism using a fuse. A fuse 901 is connected to the wiring between the power supply 111 and the load 112. The fuse 901 is cut when an overcurrent flows, and stops the power supply from the power supply 111 to the load 112.

  FIG. 1 (b) shows an example of an over current protection mechanism using a comparator. The comparator 131 disconnects the FET 121 when the voltage difference due to the current flowing through the resistor 141 becomes equal to or greater than the threshold, thereby stopping the power supply from the power supply 111 to the load 112.

  Here, Patent Document 1 performs on / off switching of the drive current for a predetermined load, shunts the drive current to detect an overcurrent, compares the overcurrent with a predetermined reference, and generates an error based on the comparison result. An over current protection circuit for protecting current is disclosed.

  Further, Patent Document 2 detects a voltage at a connection point between the switch unit and the load, holds the switch unit in a conductive state when the voltage does not exceed the threshold, and when the voltage exceeds the threshold. Disclosed is a power supply circuit that controls a non-conduction state through a switch control unit.

Unexamined-Japanese-Patent No. 2004-229407 Unexamined-Japanese-Patent No. 2004-236405

  Overcurrent protection from the power supply to the load should be performed by a combination of the current value and the duration of the current value. For example, when the current value is extremely larger than the rated value, it is necessary to stop the energization even if the duration of the current value is short. The reason is that even if the duration is short, the damage to the load is large. On the other hand, if the current value is a little larger than the rated value, it should be stopped if the duration of the current value is long. The reason is that damage to the load occurs as the current value continues for a long time.

  FIG. 2 is an image diagram showing an example of the range of the combination of the current value and the duration time for stopping the energization.

  In this example, there is no problem in supplying power from the power supply to the load in the safety area below the line 199 where the combination of time and current is shown in the figure. On the other hand, in the critical area where the combination of time and current is above line 199, the power supply to the load should be shut off. Note that the shape and position of the line 199 may vary depending on the type of load and power supply.

  Here, in the method using a fuse such as the method shown in FIG. 1A, it is difficult to control the cutting of the fuse accurately, particularly when the duration of the current value is short.

  Moreover, the method which FIG.1 (b) represents, and the method which patent document 1 and 2 disclose can detect a predetermined voltage value, and can stop electric power supply. However, these methods can not stop power supply by the combination of the current value and the duration of the current value.

  FIG. 3 is an image diagram showing a protection area when a general protection circuit is installed. The protection area shown in the figure is an area in which power supply is stopped by the protection circuit. In the case shown in FIG. 3, even if the combination of the current value and the duration thereof belongs to the dangerous area, the power supply is not stopped if it does not belong to the protected area.

  Although illustration is omitted, if the lower limit of the current of the protected area is lowered and the protected area is expanded, the dangerous area which does not belong to the protected area can be reduced but the safety area does not need protection. The region where current can not be conducted is expanded. That is, unnecessary operation of the protection circuit occurs.

  An object of the present invention is to provide an output device or the like which can bring the range of the combination of the current value and the duration thereof close to an inappropriate range as the combination.

  The output device of the present invention attenuates at least a part of frequency components higher than a predetermined positive frequency among frequency components included in an input voltage representing a value of current supplied from a power source to a load at a constant voltage and outputs Between the high frequency cutoff circuit, the second voltage which is the input voltage after passing the high frequency cutoff circuit, and the first voltage which is a constant voltage smaller than the maximum value of the second voltage And a supply unit capable of supplying a third voltage to the switch, the switch being capable of disconnecting a power path between the power supply and the load in a predetermined case.

  The output device and the like of the present invention can bring the range of the combination of the current value and the duration to stop the power supply close to an inappropriate range as the combination.

It is a conceptual diagram showing the example of a general over-current prevention mechanism. It is an image figure showing the example of the range of the combination of the current value and the continuation time of the current value which should stop energization. It is an image figure showing the protection field at the time of installing a general protection circuit. It is a conceptual diagram showing the example of composition of the circuit to which the protection circuit of a first embodiment is applied. It is a conceptual diagram showing the 1st example of the time change of each voltage. It is a conceptual diagram showing the 2nd example of the time change of each voltage. It is a conceptual diagram showing the 3rd example of the time change of each voltage. It is a conceptual diagram showing the 4th example of the time change of each voltage. It is a figure showing the example of a range of the combination of an electric current value and its continuation time where terminals TB-TC are disconnected. It is a conceptual diagram showing the structural example of the circuit to which the protection circuit of 2nd embodiment is applied. It is a figure showing the example of the range of the combination of the current value and its continuation time where the output of output unit 166a becomes H level. It is a figure showing the example of a range of the combination of a current value and its continuation time in which the output of output unit 166b serves as H level. It is a figure showing the example of a range of the combination of the current value which the output of output unit 166c becomes H level, and its continuation time. It is a figure showing the example of the range of the combination of the current value and the continuation time from which the output from either output unit cuts a path. It is a block diagram showing the minimum composition of the output device of an embodiment.

First Embodiment
The first embodiment relates to a protection circuit in which one unit outputs a signal for cutting a path.
[Configuration and operation]
FIG. 4 is a conceptual diagram showing a configuration of a circuit 801 a which is an example of a circuit to which the protection circuit of this embodiment is applied.

  The circuit 801a includes a power supply 111, a load 112, and a protection circuit 101a.

  The load 112 is, for example, an apparatus or device.

  The power supply 111 supplies the voltage Vs to the terminal TA of the protection circuit 101a. The current value of the current i which is a current passing through the resistor 141 changes depending on the condition of the load 112.

  The protection circuit 101a is an example of the protection circuit of the first embodiment.

  The protection circuit 101 a includes resistors 141 and 144, an FET 121, and an output unit 166. Here, FET is an abbreviation for Field effect transistor.

  The output unit 166 includes resistors 142 and 143, an RC circuit 171, and a comparator 131. Here, RC is an abbreviation for resistance and capacitor.

  The RC circuit 171 includes a resistor 161 and a capacitor 151. One terminal of the capacitor 151 is connected to a common voltage portion such as common ground or ground. The voltage Va is input to the negative input terminal of the comparator 131. The voltage Va is a value obtained by dividing the value obtained by multiplying the voltage Vs by the resistance value of the resistor 143 by the sum of the resistance values of the resistors 142 and 143. The resistors 142 and 143 are provided for the purpose of setting the value of the voltage Va.

  The voltage Ve is supplied to the terminal TC. The voltage Ve is a value obtained by subtracting the resistance value of the resistor 141 and the current value of the current i from the voltage Vs. Here, the current i is a current flowing through the resistor 141. As described above, since the voltage Vs is constant, when the value of the current i increases due to an overcurrent or the like, the value of the voltage Ve decreases by the increase.

  The voltage Ve becomes the voltage Vd by the RC circuit 171. The RC circuit 171 includes a resistor 161 and a capacitor 151. The RC circuit 171 is a high frequency cutoff circuit that can shut off part of frequency components included in the voltage Ve.

  The capacitor 151 of the RC circuit 171 attenuates the predetermined frequency component included in the voltage Ve by introducing the predetermined frequency component to the ground. For example, it is assumed that time change of voltage drop occurs in voltage Ve due to time change of rise of current i. In that case, the time change of the voltage drop is the superposition of the frequency change of the voltage drop. The RC circuit 171 attenuates a predetermined frequency component as described above, so that the time change of the voltage drop can be blunted and the degree of the voltage drop can be reduced.

  In the embodiment, the voltage drop refers to a voltage drop from a reference value of voltage. For example, the reference value of the voltage Ve is the value of the voltage Ve when the current value of the current i is a normal value.

  The degree of the attenuation can be adjusted by a combination of the capacity of the capacitor 151 and the resistance value of the resistor 161.

  On the other hand, the RC circuit 171 does not affect the DC component included in the voltage Ve.

  The voltage Vd is input to the positive input terminal of the comparator 131.

  The comparator 131 outputs a high level (H level) voltage Vt when the voltage obtained by subtracting the voltage Va from the voltage Vd is equal to or higher than the voltage Vt.

  On the other hand, when the voltage obtained by subtracting the voltage Va from the voltage Vd is less than the voltage Vt, the comparator 131 outputs the voltage Vt at a low level (L level).

  The resistance value of each of the resistors included in the output unit 166 and the capacitance of the capacitor 151 are desired to cause the comparator 131 to output the H level voltage Vt, depending on the degree of voltage drop of the voltage Ve and the duration of the voltage drop. It is adjusted and set. The adjustment is performed, for example, as follows.

  For example, it is assumed that the voltage Vt is set to be H level when the degree of voltage drop is large regardless of the duration of the voltage drop. In that case, the resistance value of the resistor 142 and the resistance value of the resistor 143 are set so that the value obtained by dividing the resistance value of the resistor 143 by the sum of the resistance value of the resistor 142 and the resistance value of the resistor 143 becomes smaller. . This is to reduce the voltage Va. If the value of the voltage Va is smaller, the voltage Vd in which the voltage drop is generated due to the voltage drop of the voltage Ve falls below the voltage Va only when the degree of the voltage drop of the voltage Ve is larger.

  Further, for example, in order to make the voltage Vt be L level when the duration of the voltage drop is short, it is effective to make the capacity of the capacitor 151 larger. When the duration of the voltage drop is short, the high frequency component included in the time change of the voltage drop is large, and the high frequency component is removed by increasing the capacity of the capacitor 151.

  From the above, the extent of the voltage drop of the voltage Ve and the range of the duration of the voltage drop when the voltage Vt becomes H level can be adjusted by the resistance value of each resistor included in the output unit 166 and the capacitance of the capacitor 151.

  When the comparator 131 outputs H level, the current ih generated by the voltage difference between the voltage Ve and H level flows through the resistor 144. Therefore, the gate voltage of the FET 121 is lower than the source voltage by a voltage Vh obtained by multiplying the resistance value of the resistor 144 by the current value of the current ih. In this case, the FET 121 disconnects between the source and the drain. The resistance value of the resistor 144 is set so that the above of the FET 121 can be performed.

  On the other hand, when the comparator 131 outputs L level, the current il generated by the voltage difference between the voltage Ve and L level flows through the resistor 144. Therefore, the gate voltage of the FET 121 is lower than the source voltage by a voltage V1 obtained by multiplying the resistance value of the resistor 144 by the current value of the current il. In this case, the FET 121 conducts between the source and the drain. The resistance value of the resistor 144 is set to enable the above-described operation of the FET 121.

  In this manner, the FET 121 disconnects between the terminals TC and TB when the comparator 131 outputs the H level. Also, when the comparator 131 outputs L level, the FET 121 conducts between the terminals TC and TB.

  When the FET 121 conducts between the terminals TC and TB, power supply from the power supply 111 to the load 112 is performed. On the other hand, when the FET 121 insulates between the terminals TC and TB, the power supply from the power supply 111 to the load 112 is stopped.

  Next, the influence on the voltage Vt of the AC voltage superimposed on the DC voltage serving as the basis of the voltage Vs will be described.

  FIG. 5 is a conceptual diagram showing a first example of time change of each of voltages Va, Vd, Ve and Vt. Here, each of voltages Va, Vd, Ve and Vt is as shown in FIG.

  The voltage Ve starts to decrease from the reference value at time T1 due to the increase of the current i shown in FIG. 4, and increases after reaching a minimum and returns to the reference value at time T2.

  On the other hand, the waveform of the frequency component of the voltage Vd is blunted by the influence of the RC circuit 171 shown in FIG. The voltage Vd starts to decrease from the reference value at time T1, reaches a local minimum, and returns to the reference value at time T3.

  The voltage Vd does not fall below the voltage Va in the period shown in FIG. Therefore, the voltage Vt of the comparator 131 shown in FIG. 4 is maintained at L level during synchronization. Thereby, the FET 121 keeps the state between the terminals TB and TC shown in FIG. 4 in a conductive state during synchronization.

  FIG. 6 is a conceptual diagram showing a second example of time change of each of voltages Va, Vd, Ve and Vt. Here, voltages Va, Vd, Ve and Vt are as shown in FIG.

  The voltage Ve starts decreasing from the reference value at time T4 due to the increase of the current i shown in FIG. 4, and increases after reaching a minimum and returns to the reference value at time T6. The amount of decrease of the voltage Ve from the reference value is larger than that shown in FIG.

  On the other hand, the waveform of the frequency component of the voltage Vd is blunted by the influence of the RC circuit 171 shown in FIG. The voltage Vd starts to decrease from the reference value at time T6, reaches a local minimum, and returns to the reference value at time T8.

  The voltage Vd falls below the voltage Va in a period between time T5 and time T7. Therefore, the voltage Vt of the comparator 131 shown in FIG. 4 switches from L level to H level at time T5. Therefore, the FET 121 disconnects between the terminals TB and TC shown in FIG. 4 at time T5.

  Furthermore, the voltage Vt switches from H level to L level at time T7. Therefore, the FET 121 conducts the terminals TB and TC at time T7.

  FIG. 7 is a conceptual diagram showing a first example of time change of each of voltages Va, Vd, Ve and Vt. Here, voltages Va, Vd, Ve and Vt are as shown in FIG.

  The voltage Ve starts decreasing from the reference value at time T9 due to the increase of the current i shown in FIG. 4, and increases after reaching a minimum and returns to the reference value at time T10.

  On the other hand, the waveform of the frequency component of the voltage Vd is blunted by the influence of the RC circuit 171 shown in FIG. The voltage Vd starts to decrease from the reference value at time T9, reaches a substantially constant value lower than the reference value, and returns to the reference value at time T11.

  The voltage Vd does not fall below the voltage Va in the period shown in FIG. Therefore, the voltage Vt of the comparator 131 shown in FIG. 4 is maintained at L level during synchronization. Thereby, the FET 121 keeps the state between the terminals TB and TC shown in FIG. 4 in a conductive state during synchronization.

  FIG. 8 is a conceptual diagram showing a third example of time change of each of voltages Va, Vd, Ve and Vt. Here, voltages Va, Vd, Ve and Vt are as shown in FIG.

  The voltage Ve starts decreasing from the reference value at time T12 due to the increase of the current i shown in FIG. 4, and increases after reaching a minimum and returns to the reference value at time T15. The amount of decrease of the voltage Ve from the reference value is larger than that shown in FIG.

  On the other hand, the waveform of the frequency component of the voltage Vd is blunted by the influence of the RC circuit 171 shown in FIG. The voltage Vd starts to decrease from the reference value at time T12, reaches a local minimum, and returns to the reference value at time T16.

  The voltage Vd falls below the voltage Va in a period between time T13 and time T14. Therefore, the voltage Vt of the comparator 131 shown in FIG. 4 switches from L level to H level at time T13. Therefore, the FET 121 disconnects between the terminals TB and TC shown in FIG. 4 at time T13.

  Then, the voltage Vt switches from H level to L level at time T14. Therefore, the FET 121 causes the terminals TB and TC to conduct at time T14.

  FIG. 9 is a diagram showing an example of the range of the combination of the value of the current i and the duration thereof in which the FET 121 shown in FIG. 4 cuts between the terminals TB and TC. When the current value i2 continues for 10000 ms or more, the FET 121 disconnects between the terminals TB and TC (disconnects between the terminals). Here, the current value i2 is a current larger than the reference current i1.

  The lower limit of the current value at which the FET 121 performs terminal-to-terminal disconnection increases with the decrease in the duration when the duration (the duration) in which the current value continues is 10000 ms or less.

The shape of the cutting region can be adjusted to some extent by appropriately selecting the value of the resistor 161 of the RC circuit 171 and the capacitance of the capacitor 151, and the values of the resistors 142 and 143 shown in FIG.
[effect]
The protection circuit according to the present embodiment is based on the magnitude of the voltage Va input to the negative input terminal of the comparator and the voltage Vd which causes the input voltage to drop by the current flowing through the shunt resistor and then pass through the RC circuit. Switch between conduction and disconnection. In that case, the relationship between the current value at which the switching from conduction to disconnection is performed and the duration of the current value can be adjusted by the value of the capacitor forming the RC circuit and the value of the voltage Va. . Accordingly, the protection circuit can bring the cut area in the combination of the current value and its duration close to the desired range.
Second Embodiment
The second embodiment is an embodiment related to a protection circuit in which a plurality of units output signals for path disconnection.
[Configuration and operation]
FIG. 10 is a conceptual diagram showing a configuration of a circuit 801 b which is an example of a circuit to which the protection circuit of this embodiment is applied.

  The circuit 801 b includes a power supply 111, a load 112, and a protection circuit 101 b.

  The power supply 111 supplies a voltage Vs, which is a constant voltage, to the terminal TA of the protection circuit 101b. The value of the current i supplied to the load 112 by the voltage Vs changes according to the condition of the load 112.

  The protection circuit 101b includes resistors 141 and 144, an FET 121, and output units 166a to 166c.

  The description of the output unit 166a is the same as the description of the output unit 166 shown in FIG. That is, the output unit 166, the resistors 142, 143 and 161, the capacitor 151, the comparator 131, the RC circuit 171, and replacement of adding the alphabet a at the end of each of the voltages Va, Vd and Vt.

  The explanation of the output unit 166b is the same as the explanation of the output unit 166 shown in FIG. That is, the output unit 166, the resistors 142, 143 and 161, the capacitor 151, the comparator 131, the RC circuit 171, and replacement of adding an alphabet b at the end of each of the voltages Va, Vd and Vt.

  The explanation of the output unit 166c is the following replacement of the explanation of the output unit 166 shown in FIG. That is, the output unit 166, the resistors 142, 143 and 161, the capacitor 151, the comparator 131, the RC circuit 171, and replacement of adding alphabet c at the end of each of the voltages Va, Vd and Vt.

  When one of the comparators 131a to 131c outputs the H level, the current ih generated by the voltage difference between the voltage Ve and the H level flows through the resistor 144. Therefore, the gate voltage of the FET 121 is lower than the source voltage by a voltage Vh obtained by multiplying the resistance value of the resistor 144 by the current value of the current ih. In this case, the FET 121 does not cut off between the source and the drain. The resistance value of the resistor 144 is set so that the above of the FET 121 can be performed.

  On the other hand, when all of the comparators 131a to 131c output L level, the current il generated by the voltage difference between the voltage Ve and the L level flows through the resistor 144. Therefore, the gate voltage of the FET 121 is lower than the source voltage by a voltage V1 obtained by multiplying the resistance value of the resistor 144 by the current value of the current il. In this case, the FET 121 disconnects between the source and the drain. The resistance value of the resistor 144 is set to enable the above-described operation of the FET 121.

  Thus, the FET 121 disconnects between the terminals TC and TB when any of the comparators 131a to 131c outputs H level. Further, when all of the comparators 131a to 131c output the L level, the FET 121 conducts between the terminals TC and TB.

  When the FET 121 conducts between the terminals TC and TB, power supply from the power supply 111 to the load 112 is performed. On the other hand, when the FET 121 insulates between the terminals TC and TB, the power supply from the power supply 111 to the load 112 is stopped.

  As described above, the degree of voltage drop of voltage Vs at which each of the outputs (voltages Vta to Vtc) from the comparators of each output unit becomes H level and the duration of the voltage drop are included in the output unit It can be adjusted by the resistance value of each resistor and the capacity of the capacitor. Then, the FET 121 disconnects between the terminals TC and TB when one of the outputs from the respective output units is at the H level. Therefore, the protection circuit 101b makes the range of the combination of the voltage drop of the voltage Vt at which the FET 121 cuts between the terminals TC and TB and the duration of the voltage drop more finely than the protection circuit of the first embodiment. It is possible to set. The specific example will be described below.

  In the output unit 166a shown in FIG. 10, the range of the combination of the current value of the current i and the duration thereof is as shown in FIG. 11 where the voltage Vta output from the output unit 166a becomes H level. As shown in. FIG. 11 is a diagram showing an example of the range of the combination of the current value and the duration thereof in which the output of the output unit 166a becomes H level.

  Further, in the output unit 166b shown in FIG. 10, as a result of setting each resistance value and the capacitance of the capacitor, the voltage Vtb which is the output of the output unit 166b becomes H level. As shown in FIG. FIG. 12 is a diagram showing an example of the range of the combination of the current value and the duration thereof in which the output of the output unit 166b becomes H level.

  Further, in the output unit 166c shown in FIG. 10, as a result of setting each resistance value and the capacitance of the capacitor, the voltage Vtc which is the output of the output unit 166c becomes H level, a combination of the current value of the current i and its duration As shown in FIG. FIG. 13 is a diagram showing an example of the range of the combination of the current value and the duration thereof in which the output of the output unit 166c becomes H level.

  In the above case, any one of voltages Vta, Vtb and Vtc cuts between terminals TC and TB. The range of the combination of the current value of current i and the duration thereof is the range represented by hatching in FIG. . FIG. 14 is a diagram showing an example of the range of the combination of the current value at which the output from any output unit cuts the path and the duration thereof. As described above, when one of the output units outputs the H level, the FET 121 shown in FIG. 10 stops the power supply from the power supply 111 to the load 112.

  Here, it is temporarily assumed that the region which is not preferable as the current supplied to the load 112 shown in FIG. 10 and the duration thereof is the dangerous region shown in FIG. The dangerous area is the area above the line 199 represented in FIG.

  In that case, the dangerous area shown in FIG. 14 is similar to the range in which the power supply from the power source 111 to the load 112 is stopped by the protection circuit 101b, which is indicated by hatching.

  Thus, the protection circuit 101b separately sets the range of the combination of the current value of the current i at which the output of each of the three output units becomes H level and its duration, and one of those outputs is H Stop the power supply at the level. Therefore, the protection circuit 101b is designed to bring the dangerous area close to the range of the combination of the current value of the current i for stopping the power supply and the duration thereof, as compared with the case of one output unit as in the first embodiment. It is easy.

The number of output units in the protection circuit according to the present embodiment is not limited to three as described above, but may be any plural number.
[effect]
The protection circuit of the present embodiment has the same configuration as the protection circuit of the first embodiment, and exhibits the same effects as the effects exhibited by the protection circuit of the first embodiment.

  The protection circuit of this embodiment separately sets the range of the combination of the current value of the current i at which the output of each of the three output units becomes H level and its duration, and one of those outputs is H level. Power supply can be shut off. Accordingly, the protection circuit is easier to design to bring the undesirable range as a combination of the current value of the current i and its duration close to the combination range in which the power supply is stopped.

  FIG. 15 is a block diagram showing the configuration of an output device 166x, which is the minimum configuration of the output device of the embodiment.

  The output device 166x includes a high frequency cutoff circuit 151x and a supply unit 131x.

  The high frequency cutoff circuit 151x attenuates at least a part of frequency components higher than a predetermined positive frequency among frequency components included in the input voltage representing the value of the current supplied from the power supply to the load at a constant voltage and outputs Do.

  The supply unit 131 x has a predetermined difference between a second voltage, which is the input voltage after passing through the high-frequency cutoff circuit, and a first voltage, which is a constant voltage smaller than the maximum value of the second voltage. In some cases, a third voltage may be supplied to the switch which may disconnect the power path between the power supply and the load by the switch.

  The output device 166x can adjust the increase amount of the current value supplying the third voltage by selecting the value of the first voltage. Further, the output device 166x can adjust the duration of the increase of the current value supplying the third voltage by adjusting the cutoff frequency of the high frequency cutoff circuit 151x. And, the value of the first voltage and the cutoff frequency are independent.

  Accordingly, the output device 166x can set the combination of the increase of the current value and the duration to supply the third voltage.

  Therefore, the output device 166x can set a combination of the increase in the current value and the duration for stopping from the power supply to the load.

  The supply of power from the power supply to the load is stopped when the combination of the increase in the current value and the duration thereof is within a predetermined range.

Therefore, the output device 166x can bring the range of the combination of the current value for stopping the power supply and the duration of the current value close to the inappropriate range as the combination.
Therefore, the output device 166x exhibits the effect described in the item of [Effect of the invention] by the above configuration.

  The high frequency cutoff circuit 151x illustrated in FIG. 15 is, for example, each of the RC circuit 171 illustrated in FIG. 4 and the RC circuits 171a to 171c illustrated in FIG.

  The supply unit 131x illustrated in FIG. 10 is, for example, each of the comparator 131 illustrated in FIG. 4 and the comparators 131a to 131c illustrated in FIG.

  As mentioned above, although each embodiment of the present invention was described, the present invention is not limited to the above-mentioned embodiment, and can carry out further modification, substitution, adjustment in the range which does not deviate from the basic technical idea of the present invention. It can be added. For example, the configuration of the elements shown in each drawing is an example to help the understanding of the present invention, and the present invention is not limited to the configuration shown in these drawings.

  In addition, part or all of the above-described embodiment may be described as in the following appendices, but is not limited to the following.

(Supplementary Note 1)
A high frequency cutoff circuit that attenuates and outputs at least a part of frequency components higher than a predetermined positive frequency among frequency components included in an input voltage representing a value of current supplied from a power source to a load at a constant voltage;
When the difference between the second voltage, which is the input voltage after passing through the high-frequency cutoff circuit, and the first voltage, which is a predetermined constant voltage smaller than the maximum value of the second voltage, is predetermined, A supply unit capable of supplying the switch with a third voltage capable of disconnecting a power path between the power supply and the load by the switch;
An output device comprising:

(Supplementary Note 2)
The output device according to appendix 1, wherein the input voltage is a voltage at a load-side terminal of a first resistor provided in the power path.

(Supplementary Note 3)
The output device according to Appendix 1 or 2, wherein the first voltage is derived from a power supply voltage output from the power supply.

(Supplementary Note 4)
The output device described in appendix 3, wherein the derivation is performed by dividing the power supply voltage by a second resistor and a third resistor.

(Supplementary Note 5)
The output device according to any one of appendices 1 to 4, wherein the high frequency cutoff circuit comprises a grounded capacitor.

(Supplementary Note 6)
The output device according to any one of appendices 1 to 5, wherein the switch is a field effect transistor.

(Appendix 7)
6. The output device according to appendix 6, wherein a fifth resistor is connected in parallel between the source and the drain of the field effect transistor.

(Supplementary Note 8)
The output device according to any one of appendices 1 to 7, wherein the supply unit is a comparator.

(Appendix 9)
The output device according to appendix 8, wherein the first voltage is inputted to the minus terminal of the comparator, and the second voltage is inputted to the plus terminal of the comparator.

(Supplementary Note 10)
A voltage drop of the second voltage and a duration of the voltage drop, each of the plurality of output units including the high frequency cutoff circuit and the supply unit, each of the output units supplying the third voltage to the switch; The output device according to any one of appendices 1 to 9, wherein the combined range of the combined ranges of is larger than any of the combination ranges.

(Supplementary Note 11)
A protective device comprising the output device according to any one of Supplementary Notes 1 to 10, and the switch.

(Supplementary Note 12)
A high frequency cutoff circuit that attenuates and outputs at least a part of frequency components higher than a predetermined positive frequency among frequency components included in an input voltage representing a value of current supplied from a power source to a load at a constant voltage;
When the difference between the second voltage, which is the input voltage after passing through the high-frequency cutoff circuit, and the first voltage, which is a predetermined constant voltage smaller than the maximum value of the second voltage, is predetermined, A supply unit capable of supplying the switch with a third voltage capable of disconnecting a power path between the power supply and the load by the switch;
In an output device comprising
The setting method which sets the range of the combination of the said value in which the said cutting | disconnection is performed, and the time which the said value continues.

(Supplementary Note 13)
15. The setting method as set forth in appendix 12, wherein the setting is performed by selection of the first voltage and the positive frequency.

101a, 101b Protection Circuit 111 Power Supply 112 Load 121 FET
131, 131a, 131b, 131c Comparator 131x supply part 141, 141a, 141b, 141c, 142, 142a, 142b, 142c, 143, 143a, 143b, 143c, 144, 161, 161a, 161b, 161c, resistance 151, 151a , 151b, 151c capacitor 151x high frequency cutoff circuit 166, 166a, 166b, 166c output unit 171, 171a, 171b, 171c RC circuit 199 line 801a, 801b circuit 901 fuse

Claims (9)

A high frequency cutoff circuit that attenuates and outputs at least a part of frequency components higher than a predetermined positive frequency among frequency components included in an input voltage representing a value of current supplied from a power source to a load at a constant voltage;
When the difference between the second voltage which is the input voltage after passing through the high frequency cutoff circuit and the first voltage which is a constant voltage smaller than the maximum value of the second voltage is a predetermined value, the power supply A supply unit capable of supplying the switch with a third voltage capable of disconnecting the power path between the switch and the load by the switch;
An output device comprising:   The output device according to claim 1, wherein the input voltage is a voltage at a load-side terminal of a first resistor provided in the power path.   The output device according to claim 1, wherein the first voltage is derived from a power supply voltage output from the power supply.   The output device according to claim 3, wherein the derivation is performed by dividing the power supply voltage by a second resistor and a third resistor.   The output device according to any one of claims 1 to 4, wherein the switch is a field effect transistor.   A voltage drop of the second voltage and a duration of the voltage drop, each of the plurality of output units including the high frequency cutoff circuit and the supply unit, each of the output units supplying the third voltage to the switch; The output device according to any one of claims 1 to 5, wherein an overlapping range of the combination of is larger than a range of any of the combinations.   A protective device comprising the output device according to any one of claims 1 to 6 and the switch. A high frequency cutoff circuit that attenuates and outputs at least a part of frequency components higher than a predetermined positive frequency among frequency components included in an input voltage representing a value of current supplied from a power source to a load at a constant voltage;
When the difference between the second voltage which is the input voltage after passing through the high frequency cutoff circuit and the first voltage which is a constant voltage smaller than the maximum value of the second voltage is a predetermined value, the power supply A supply unit capable of supplying the switch with a third voltage capable of disconnecting the power path between the switch and the load by the switch;
In an output device comprising
The setting method which sets the range of the combination of the said value in which the said cutting | disconnection is performed, and the time which the said value continues.   The setting method according to claim 8, wherein the setting is performed by selecting the first voltage and the positive frequency.

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