JP3017156B2 - Adjustable fixed resistor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adjustable fixed resistor, and more particularly, to an adjustable fixed resistor capable of changing a resistance value by separating an appropriate resistor from a plurality of built-in resistors. Related to resistors.

[0002]

2. Description of the Related Art For example, since the amplification degree of an operational amplifier amplifier circuit to which feedback is applied is determined by a feedback resistance, a circuit change occurs, and when adjusting the amplification degree, it is necessary to change the resistance value of the feedback resistor. is there.

Further, even in an amplifier circuit using a bipolar transistor, the amplification degree is adjusted by adjusting the base resistance value for self-bias. Therefore, when adjusting the amplification degree, it is necessary to change the base resistance.

Therefore, conventionally, in such a case, the resistor once mounted on the substrate is replaced with another resistor.

[0005]

However, the operation of replacing a resistor mounted on a board with another resistor is a complicated work such as soldering. May adversely affect the device.

The present invention has been made in view of the above problems, and has as its object to provide an adjustable fixed resistor that can easily adjust the resistance value even after being mounted on a board and does not require replacement. I do.

[0007]

In order to achieve the above object, the adjustable fixed resistor of the present invention comprises four or more resistors.
Two resistors arranged in a row, two of which are adjacent on the center side
An external connection terminal is provided at one end of the external connection terminal.
Resistor and one or more resistors arranged outside the resistor.
Connect one end of the armor so that it can be disconnected between each resistor,
And when connecting the other ends of the four or more resistors,
In each case, each resistor except between the resistors provided with the external connection terminals
The structure is such that it can be cut between arms.

According to the invention having such a configuration, a parallel resistor in which a plurality of resistors are incorporated in parallel can be used, and an appropriate resistor can be separated from these resistors.
When it is necessary to change the resistance value after mounting on the board, it is possible to separate the appropriate resistor from the parallel resistor and change the resistance value. Can be changed.

[0009] Regulating the fixed resistor according to claim 2, the plurality of resistors Ri Do rod-shaped resistor, and a connecting line
Therefore, each resistor is connected, and each resistor can be removed by cutting the connection line.

According to the invention of this structure, the electrically isolated resistors by cutting the connection line because it requires not left on the substrate, it is possible to reliably separated.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an adjustable fixed resistor according to the present invention will be described below with reference to the drawings.

FIGS. 1A and 1B show an adjustable fixed resistor according to a reference embodiment of the present invention. FIG . 1A is a perspective view, and FIG. 1B is a side view showing the AA plane in FIG. is there.

[0013] The regulated fixed resistor 1a is in this figure
Three independent pillar-shaped first and second resistors R1 and R
The second and third resistors R3 are arranged in a horizontal row with their peripheral surfaces in contact with each other. These resistors R1, R2, R
3 are each covered with, for example, plastic. Connecting lines 11 and 12 connecting these resistors R1, R2 and R3 are connected to the terminals at both end surfaces of the resistors R1, R2 and R3, respectively.
1, R2 and R3 are connected and bound to each other via connection lines 11 and 12. Here, the external connection terminal of the adjustable fixed resistor 1a is provided in the third resistor R3, and the connection line 1
1 and 12 are also used.

[0014] These resistors R1, R2, R3 is electrically connected to the connecting wires 11 and 12 at both end faces, therefore, the regulated fixed resistors 1a, as shown in FIG. 2, the first resistor R1, the second resistor R2, and the third resistor R3 are connected to the connection line 1
1 and 12 are connected in parallel.

The connection lines 11 and 12 have a first notch 11a between the first resistor R1 and the second resistor R2.
(Not shown), and a second notch 11b (not shown) is provided between the second resistor R2 and the third resistor R3. By cutting the first cutout 11a with, for example, a nipper, the first resistor R1 can be easily separated and removed from the adjustable fixed resistor 1a. And a third resistor R3. Further, by cutting the second cutout portion 11b with, for example, a nipper, the second resistor R2 can be easily separated and removed from the adjustable fixed resistor 1a. It consists of only three resistors R3.

The initial resistance value _RA of the adjustable fixed resistor 1a having the first to third resistors R1, R2, R3 is represented by the following equation (1).

[0017]

R _A = R ₁ R ₂ R ₃ / (R ₁ R ₂ + R ₂ R ₃ + R ₁ R ₃ ) (1)

[0018] Here, the resistance value of R ₁ is R1, R ₂ the resistance value of R2, R ₃ is a resistance value of R3.

[0019] Next, a specific resistance adjusting method for such control-type fixed resistors 1a with reference to FIG.

FIG . 3 shows the adjustable fixed resistor 1 shown in FIG.
shows a circuit of a, the resistance value R ₁ of the first resistor R1 is 90 ohms, the resistance value R ₂ of the second resistor R2 is 90 ohms, the case where the resistance value R ₃ of the third resistor R3 is 90 ohms Is shown.

The resistance value R _A of the first through the initial adjustment type resistors 1a having a third resistor R1, R2, R3 is represented by the above formula (1), a 30 [Omega.

When it is necessary to change the resistance value after mounting such an adjustable fixed resistor 1a on a substrate, the first cutouts 11a and 12a or the second cutouts 11b and 1b
The connection lines 11 and 12 are cut at 2b.

[0023] For example, when cutting the connection line 11, 12 in the first notch portion 11a indicated by the broken line in FIG. 3, the first resistor R1 is separated excised from regulated fixed resistors 1a, regulated The fixed resistor 1a includes a second resistor R2 and a third resistor R3. The resistance R _B of the regulated fixed resistors in this case, represented by the following formula (2).

[0024]

R _B = R ₂ R ₃ / (R ₂ + R ₃ ) (2)

[0025] Therefore, the 45Ω by substituting the resistance value (2).

When the connection lines 11 and 12 are cut at the second notch 11b shown by the broken line in the figure, the adjustable fixed resistor 1a is composed of only the third resistor R3. Therefore, the resistance value R of the adjustable fixed resistor 1a in this case is
_C becomes 90Ω.

[0027] Thus, the regulated fixed resistors 1a
Can realize three kinds of resistance values of 30Ω, 45Ω and 90Ω, and can be changed by a resistance value lower than the resistance to be used, so that the kind of resistance required in circuit design can be reduced.

Further , the use of the resistor in the vicinity of the transformer or in a portion where the base resistance value of the transistor needs to be adjusted enables the resistance adjustment without replacing the resistor.

In the above-mentioned adjustable fixed resistor 1a, the number of resistors has been described as three. However, it is needless to say that four or more resistors may be used. Although they have the same resistance, each resistor may have a different resistance.

Next, Fig. 4 will be described embodiments of the regulated fixed resistors of the present invention with reference to FIG.

As shown in FIG . 4, the adjustable fixed resistor 1b
Are a first resistor group PR1 in which a first resistor R11 and a third resistor R13 are connected in parallel, a second resistor R12 and a fourth resistor R12.
A second resistor group PR2 to which the resistor R14 is connected in parallel is connected in series.

[0032] A specific appearance of the regulated fixed resistors 1b in FIG. FIG. 5A shows the adjustable fixed resistor 1b.
5 (b) is a view as seen from plane BB in FIG. 5 (a), and FIG. 5 (c) is a view as seen from plane CC in FIG. 5 (a).

The adjustable fixed resistor 1b shown in FIG . 5 has four resistors, ie, a third resistor R13, a first resistor R11,
The second resistor R12 and the fourth resistor R14 are assembled in a horizontal row in this order. The first resistor R11 on the center side and the second resistor
External connection terminals 13 and 14 are provided on the lower end face of the resistor R12 in the drawing, respectively, and terminals on the upper side of the drawing opposite to the four resistors are connected to each other by one connection line 15. Further, the first resistor R11 and the lower terminal of the third resistor R13 forming the first resistor group PR1 are connected to each other by a connection line 16, and the second resistor R12 and the second resistor R12 forming the second resistor group PR2 are connected to each other. The lower terminals of the fourth resistor R14 are connected to each other by a connection line 17, whereby the circuit shown in FIG. 4 is realized.

Further , the third resistor R13 and the first resistor R1
Each connection line 1 that connects the terminal with 1
The first between the resistors R13 and R11 of the fifth and the 16th are the first.
Notches 15a and 16a are provided, and the third resistor R13 is separated from the first resistor R11 by cutting the connection lines 15 and 16 with, for example, a nipper at the first notches 15a and 16a. It has become. Similarly, the connection lines 15, 17 between the fourth resistor R14 and the second resistor R12 are provided with second notches 15b, 17b, and the connection lines 15, 17 are provided at the second notches 15b, 17b. 1
7, the outer fourth resistor R14 can be separated from the inner second resistor R12.

Next, a description will be given resistance adjustment method of the regulated fixed resistors 1b. As shown in FIG. 4, it is assumed that the resistance values of the four resistors of the first resistor R11 to the fourth resistor R14 are all 90Ω. The first resistor R1 shown in FIG.
The initial resistance value _RC of the adjustable fixed resistor 1b including the first to fourth resistors R14 is represented by the following equation (3).

[0036]

R _C = (R ₁₁ R ₁₃ / (R ₁₁ + R ₁₃ )) + (R ₁₂ R ₁₄ / (R ₁₂ + R ₁₄ )) (3)

[0037] In the formula, R ₁₁ is the resistance value of the first resistor R11, R ₁₂ is the resistance value of the second resistor R12, R ₁₃ is the resistance value of the third resistor R13, R ₁₄ is the fourth resistor This is the resistance value of the device R14.

[0038] 90 Substituting the resistance values in the equation (3)
Ω.

The resistance value R _D of the regulated fixed resistors when disconnected by cutting the third resistor of the outer represented by the following formula (4).

[0040]

R _D = R ₁₁ + (R ₁₂ R ₁₄ / (R ₁₂ + R ₁₄ )) (4)

[0041] a 135Ω Substituting the resistance to formula (4).

[0042] The fourth further added to the third resistor R13
When disconnecting the resistor R14 is cut, the resistance R _E of the regulated fixed resistors 1b includes a first resistor R11 second resistor R
It becomes 180Ω which is a series resistance value of 12.

[0043] Thus, regulated fixed resistors 1b embodiment of the present invention, when used as 90 ohms, by disconnecting the resistor sequentially 135Omu, can be the resistance value of 180 ohms, using resistance By changing the resistance with a higher resistance, three kinds of resistances can be realized in total.

In the embodiment of the present invention described above, the number of resistors is not limited to four, and it is of course possible to increase the number of resistors in parallel.

[0045] Regulating the fixed resistor of the present invention, as described above, combining a plurality of resistors, since the resistor can be successively different resistance values by separation,
By using it for a portion that requires adjustment of the resistance value, the resistance value can be adjusted without replacing the resistor.

[0046] For example, as shown in FIG. 6 can be used for operational amplifier feedback resistor Rf such peripheral transformer. When it is necessary to adjust the amplification degree by changing the feedback resistance value, conventionally, the feedback resistor was removed from the board and a new resistor was mounted.
Since the adjustable fixed resistor of the present invention can change the resistance value only by cutting out and separating an appropriate internal resistor, the amplification degree can be adjusted by a simple operation while being attached to the substrate.

As shown in FIG. 7, when the amplification degree needs to be adjusted by using the base resistance Rb of the bipolar transistor, an appropriate resistor inside the adjustable fixed resistor is cut out and separated. Since the resistance value can be changed simply by performing the adjustment, the amplification degree can be adjusted by a simple operation while being attached to the substrate.

Further , since the adjustable fixed resistor of the present invention can realize a plurality of resistance values with one component, it is possible to reduce the types of resistors required in circuit design and contribute to cost reduction.

[0049]

As described above, according to the adjustable fixed resistor of the present invention, a plurality of resistance values can be realized with one component attached to the substrate, so that it is necessary to change the resistance value. Is used in circuits where it is expected that
The resistance can be changed without complicated resistor replacement work.

[Brief description of the drawings]

FIGS. 1A and 1B show a reference embodiment of an adjustable fixed resistor according to the present invention, wherein FIG. 1A is a perspective view, and FIG.
It is the side view seen from the surface.

FIG. 2 is a circuit diagram of the adjustable fixed resistor shown in FIG. 1;

FIG. 3 is a circuit diagram of the adjustable fixed resistor shown in FIG. 1, showing a separating resistor.

FIG. 4 is a circuit diagram showing an embodiment of an adjustable fixed resistor according to the present invention.

[5] shows an embodiment of a regulated fixed resistors of the invention, (a) is a perspective view, (b) is a side view seen from B-B surface of the (a), is (c) ( It is the side view seen from CC plane of a).

FIG. 6 is a circuit diagram showing an example in which the adjustable fixed resistor of the present invention is applied to a feedback resistor of an operational amplifier.

FIG. 7 is a circuit diagram showing an example in which the adjustable fixed resistor of the present invention is applied to a base resistance of a bipolar transistor.

[Explanation of symbols]

 1a, 1b Adjustable fixed resistor R1 First resistor R2 Second resistor R3 Third resistor R4 Fourth resistor 11 First connection line 11a First notch 11b Second notch 12 Second connection 12a 1st notch 12b 2nd notch

Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01C 13 / 02,17 / 22,17 / 24

Claims (2)

(57) [Claims] 1. At least four resistors are arranged in a row, and one end of each of two adjacent resistors on the center side is provided at each end.
The external connection terminal is provided, and the resistor provided with the external connection terminal is arranged in parallel with the outside of the resistor.
Cut one end of one or more resistors between each resistor
And connect the other ends of the four or more resistors.
In each case, each resistor except between the resistors provided with the external connection terminals
An adjustable fixed resistor characterized in that it can be cut between arms. 2. The method according to claim 1, wherein the plurality of resistors are rod-shaped resistors.
And connect each resistor with a connection line .
To, claims and characterized by being configured so as to be able to remove each of said resistor by cutting the connection line
Item 2. An adjustable fixed resistor according to Item 1 .