Equipotential shielding high-value resistor, voltage divider and low-leakage constant current source

Abstract

The invention relates to a high-value resistor, in particular to an equipotential shielding high-value resistor, a voltage divider and a low-leakage constant-current source, and aims to solve the problems that in the prior art, a high-value resistor in a constant-current source is greatly influenced by humid air and electromagnetic waves in the environment in the using process; and the accuracy of the calibration result of the calibration device is severely influenced. The invention provides an equipotential shielding high-value resistor which comprises a glass tube, a high-value resistor is arranged in the glass tube, and a high-value resistor high-end pin and a high-value resistor low-end pin of the high-value resistor are respectively led out of the glass tube from two ends of the glass tube in a sealed manner; a shielding protection resistor sleeves the outer side of the glass tube, and a shielding protection resistor high-end pin and a shielding protection resistor low-end pin are arranged at the two ends of the shielding protection resistor respectively; the equipotential shielding voltage divider provided by the invention comprises the equipotential shielding high-value resistor, and the low-leakage constant current source provided by the invention comprises the equipotential shielding voltage divider.

Description

Technical Field

[0001] The present invention relates to high-value resistors, and particularly to an equipotential shielding high-value resistor, a voltage divider and a low-leakage constant current source. Background Art

[0002] A large number of special test equipment are used at the test site of liquid rocket engines. The calibration of these special test equipment is an important means to ensure the reliability of the equipment. Now, more and more special test equipment on the test bench adopts the method of on-site calibration. On-site calibration is to calibrate the special test equipment to be calibrated and the standard equipment simultaneously under the conditions of the liquid rocket engine test site. In this calibration method, the usage conditions and calibration conditions of the special test instrument to be calibrated are the same, and only the influence of environmental factors on the calibration standard device needs to be considered.

[0003] In the calibration device, the constant current source is an important part. When the output current of the constant current source changes, it will seriously affect the accuracy of the calibration result of the calibration device. At the same time, the high-value resistor inside the constant current source is greatly affected by the humid air and electromagnetic waves in the environment during use. If on-site calibration is carried out in a harsh environment, corresponding measures must be taken to reduce the influence of the humid air and electromagnetic waves in the environment on the high-value resistor inside the constant current source. Summary of the Invention

[0004] The purpose of the present invention is to solve the technical problem that the high-value resistor inside the constant current source in the prior art is greatly affected by the humid air and electromagnetic waves in the environment during use, which seriously affects the accuracy of the calibration result of the calibration device, and to provide an equipotential shielding high-value resistor, a voltage divider and a low-leakage constant current source.

[0005] To solve the above technical problem, the technical solution provided by the present invention is as follows:

[0006] An equipotential shielding high-value resistor, characterized in that:

[0007] It includes a glass tube with both ends sealed. A high-value resistor is arranged inside the glass tube. High-value resistor high-end pins and high-value resistor low-end pins are respectively arranged at both ends of the high-value resistor. The high-value resistor high-end pin and the high-value resistor low-end pin are respectively sealed and led out to the outside of the glass tube from both ends of the glass tube;

[0008] A shielding protection resistor is sleeved outside the glass tube. Shielding protection resistor high-end pins and shielding protection resistor low-end pins are respectively arranged at both ends of the shielding protection resistor;

[0009] The shielding protection resistor high-end pin is connected to the high-value resistor high-end pin to form a high-end pin.

[0010] Further, a gap is provided between the inner wall of the glass tube and the outer wall of the high-value resistor for forming a vacuum chamber after evacuation.

[0011] Further, the cross-section of the shielding protection resistor is in an annular shape.

[0012] Further, the length of the shielding protection resistor is the same as the length of the high-value resistor.

[0013] Meanwhile, the present invention also provides an equipotential shielding voltage divider, which is characterized in that: it includes a plurality of the aforementioned equipotential shielding high-value resistors, and a plurality of switches with the same number as the equipotential shielding high-value resistors;

[0014] The contactors of the plurality of switches are all connected together as the high end of the voltage divider, and the contacts of the plurality of switches are respectively connected to the high-end pins of the plurality of equipotential shielding high-value resistors in one-to-one correspondence;

[0015] The low-end pins of the shielding protection resistors of the plurality of equipotential shielding high-value resistors are connected together;

[0016] The low-end pins of the high-value resistors of the plurality of equipotential shielding high-value resistors are connected together as the low end of the voltage divider.

[0017] Further, the number of the equipotential shielding high-value resistors is 9.

[0018] Meanwhile, the present invention also provides a low-leakage constant current source, which is characterized in that: it includes the aforementioned equipotential shielding voltage divider, and resistor R1, resistor R2, resistor R3, resistor R4, resistor R5, resistor R6, a filter circuit, operational amplifier OP3, and operational amplifiers OP1 and OP2 with their non-inverting inputs grounded;

[0019] The inverting input of operational amplifier OP1 is connected to one ends of resistor R1, resistor R3 and resistor R6;

[0020] The other end of resistor R1 is connected to the power input terminal En;

[0021] The other end of resistor R3 is connected to the output of operational amplifier OP1 and the high end of the equipotential shielding voltage divider;

[0022] The other end of resistor R6 is connected to the output of operational amplifier OP2 and one end of resistor R4;

[0023] The other end of resistor R4 is connected to the inverting input of operational amplifier OP2 and one end of resistor R5;

[0024] The other end of resistor R5 is connected to the output of operational amplifier OP3, one end of the filter circuit and one end of resistor R2;

[0025] The other end of the resistor R2 is connected to the inverting input terminal of the operational amplifier OP3;

[0026] The non-inverting input terminal of the operational amplifier OP3 is connected to the other end of the filter circuit and the low end of the voltage divider of the equipotential shielding voltage divider. The low end of the voltage divider is connected to the power output terminal U0 and is used to connect the load resistor RL.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] 1. For the equipotential shielding high-value resistor provided by the present invention, the high-value resistor is installed in a glass tube with both ends sealed, which can isolate the humid air in the environment from contacting the high-value resistor in an environment with relatively high humidity, and avoid the formation of a water film on the surface of the high-value resistor by the humid air in the humid environment, thereby solving the technical problem of leakage current formed on the surface of the high-value resistor; by sleeving a shielding protection resistor outside the glass tube to shield external electromagnetic waves with the shielding protection resistor, the influence of external electromagnetic waves on the high-value resistor inside the glass tube is reduced, and the anti-interference ability of the high-value resistor is improved.

[0029] 2. For the equipotential shielding high-value resistor provided by the present invention, a gap is provided between the inner wall of the glass tube and the high-value resistor, and the gap is evacuated to form a vacuum cavity, which can improve the insulation performance of the high-value resistor and reduce the leakage current of the high-value resistor.

[0030] 3. For the equipotential shielding voltage divider provided by the present invention, by providing a plurality of equipotential shielding high-value resistors and a plurality of switches with the same number as the plurality of equipotential shielding high-value resistors, the resistance value of the entire equipotential shielding voltage divider can be adjusted by adjusting the number of switch contactors in contact with the contacts at the same time, which helps to improve the voltage division accuracy and stability of the high-value resistor.

[0031] 4. For the low-leakage constant current source provided by the present invention, by using an equipotential shielding voltage divider and an equipotential shielding high-value resistor, the leakage of current in a humid environment and the influence of external electromagnetic waves on the high-value resistor are reduced; by connecting the equipotential shielding voltage divider in series in the circuit, the resistance value of the entire equipotential shielding voltage divider is adjusted by adjusting the number of switch contactors in contact with the contacts at the same time, so as to adjust the voltage on the equipotential shielding voltage divider and the magnitude of the output voltage, so as to improve the output stability and reliability of the low-leakage constant current source. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a schematic structural diagram of Embodiment 1 of the present invention;

[0033] Figure 2 is Figure 1 the top view of

[0034] Figure 3It is a schematic diagram of the circuit structure of Embodiment 2 of the present invention;

[0035] Figure 4 It is a schematic diagram of the circuit structure of Embodiment 3 of the present invention.

[0036] Explanation of reference numerals: 1 - glass tube, 2 - high-value resistor, 3 - high-end pin of high-value resistor, 4 - low-end pin of high-value resistor, 5 - shielding protection resistor, 6 - high-end pin of shielding protection resistor, 7 - low-end pin of shielding protection resistor, 8 - gap. Detailed implementation manners

[0037] Next, in conjunction with the accompanying drawings, the technical solutions of the present invention will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0038] Embodiment 1

[0039] As Figure 1 and Figure 2 shown, an equipotential shielding high-value resistor includes a glass tube 1 with sealed ends. A high-value resistor 2 is arranged inside the glass tube 1. Loading the high-value resistor 2 into the glass tube 1 with sealed ends can isolate the humid air in the environment from contacting the high-value resistor 2 in an environment with high humidity, and avoid the formation of a water film on the surface of the high-value resistor 2 by the humid air in the humid environment, thereby solving the technical problem of forming leakage current on the surface of the high-value resistor 2. At the same time, in order to improve the insulation performance of the high-value resistor 2 and reduce the leakage current of the high-value resistor 2, a gap 8 is arranged between the inner wall of the glass tube 1 and the outer wall of the high-value resistor 2 for forming a vacuum chamber after evacuation; evacuating the space between the inner wall of the glass tube 1 and the outer wall of the high-value resistor 2 to reduce the leakage current of the high-value resistor 2.

[0040] In order to reduce the influence of external electromagnetic waves on the high-value resistor 2 inside the glass tube 1 and improve the anti-interference ability of the high-value resistor 2, a shielding protection resistor 5 is sleeved outside the glass tube 1 to shield external electromagnetic waves with the shielding protection resistor 5; the cross-section of the shielding protection resistor 5 is circular to facilitate sleeving the shielding protection resistor 5 outside the glass tube 1; in order to make the utilization rate of the shielding protection resistor 5 the highest, the length of the shielding protection resistor 5 is set to be the same as the length of the high-value resistor 2.

[0041] High-value resistors 2 are respectively provided with a high-value resistor high-end pin 3 and a high-value resistor low-end pin 4 at both ends. The high-value resistor high-end pin 3 and the high-value resistor low-end pin 4 are respectively led out and sealed from both ends of the glass tube 1 to the outside of the glass tube 1; both ends of the shielding protection resistor 5 are respectively provided with a shielding protection resistor high-end pin 6 and a shielding protection resistor low-end pin 7; the shielding protection resistor high-end pin 6 is connected to the high-value resistor high-end pin 3 to form a high-end pin.

[0042] Embodiment 2

[0043] As Figure 3 shown, an equipotential shielding voltage divider includes 9 of the aforementioned equipotential shielding high-value resistors, and 9 switches with the same number as the equipotential shielding high-value resistors; the contactors of the 9 switches are all connected to serve as the high-end of the voltage divider, and the contacts of the 9 switches are respectively connected to the high-end pins of multiple equipotential shielding high-value resistors in one-to-one correspondence; the shielding protection resistor low-end pins of the 9 equipotential shielding high-value resistors are connected;

[0044] The low-end pins of the high-value resistors of the 9 equipotential shielding high-value resistors are connected to serve as the low-end of the voltage divider.

[0045] Embodiment 3

[0046] As Figure 4 shown, a low-leakage constant current source includes the aforementioned equipotential shielding voltage divider, as well as resistor R1, resistor R2, resistor R3, resistor R4, resistor R5, resistor R6, a filter circuit, operational amplifier OP3, and operational amplifiers OP1 and OP2 with their non-inverting inputs grounded;

[0047] The non-inverting input of operational amplifier OP1 is connected to one ends of resistor R1, resistor R3, and resistor R6;

[0048] The other end of resistor R1 is connected to the power input terminal En;

[0049] The other end of resistor R3 is connected to the output terminal of operational amplifier OP1 and the high-end of the equipotential shielding voltage divider;

[0050] The other end of resistor R6 is connected to the output terminal of operational amplifier OP2 and one end of resistor R4;

[0051] The other end of resistor R4 is connected to the non-inverting input of operational amplifier OP2 and one end of resistor R5;

[0052] The other end of resistor R5 is connected to the output terminal of operational amplifier OP3, one end of the filter circuit, and one end of resistor R2;

[0053] The other end of resistor R2 is connected to the non-inverting input of operational amplifier OP3;

[0054] The non-inverting input terminal of the operational amplifier OP3 is connected to the other end of the filter circuit and the low end of the voltage divider of the equipotential shielding voltage divider. The low end of the voltage divider is connected to the power output terminal U0 and is used to connect the load resistor RL.

[0055] By adopting an equipotential shielding voltage divider and an equipotential shielding high-value resistor, the leakage of current in a humid environment and the influence of external electromagnetic waves on the high-value resistor are reduced; the equipotential shielding voltage divider is connected in series in the circuit, and the resistance value of the equipotential shielding voltage divider is adjusted by adjusting the number of contacts between the switch contactor and the contact at the same moment, so as to adjust the voltage on the equipotential shielding voltage divider and the magnitude of the output voltage, improve the output stability and reliability of the low-leakage constant current source, and facilitate the output of a more stable current.

[0056] As described above, it is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any change or replacement within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. An equipotential shielding high-value resistor, characterized in that: It includes a glass tube (1) with sealed ends. Inside the glass tube (1), a high-value resistor (2) is arranged. At both ends of the high-value resistor (2), a high-value resistor high-end pin (3) and a high-value resistor low-end pin (4) are respectively arranged. The high-value resistor high-end pin (3) and the high-value resistor low-end pin (4) are respectively sealed and led out from both ends of the glass tube (1) to the outside of the glass tube (1); A shielding protection resistor (5) is sleeved outside the glass tube (1). At both ends of the shielding protection resistor (5), a shielding protection resistor high-end pin (6) and a shielding protection resistor low-end pin (7) are respectively arranged; The shielding protection resistor high-end pin (6) is connected to the high-value resistor high-end pin (3) to form a high-end pin.

2. The equipotential shielding high-value resistor according to claim 1, characterized in that: A gap (8) is arranged between the inner wall of the glass tube (1) and the outer wall of the high-value resistor (2) for forming a vacuum cavity after evacuation.

3. The equipotential shielding high-value resistor according to claim 2, characterized in that: The cross-section of the shielding protection resistor (5) is in an annular shape.

4. The equipotential shielding high-value resistor according to claim 3, characterized in that: The length of the shielding protection resistor (5) is the same as the length of the high-value resistor (2).

5. An equipotential shielding voltage divider, characterized in that: It includes a plurality of equipotential shielding high-value resistors according to any one of claims 1 to 4, and a plurality of switches with the same number as the equipotential shielding high-value resistors; The contactors of the plurality of switches are all connected as the high end of the voltage divider. The contacts of the plurality of switches are respectively connected in one-to-one correspondence with the high-end pins of the plurality of equipotential shielding high-value resistors; The shielding protection resistor low-end pins (7) of the plurality of equipotential shielding high-value resistors are connected; The low-end pins (4) of the high-value resistors of the plurality of equipotential shielding high-value resistors are connected as the low end of the voltage divider.

6. The equipotential shielding voltage divider according to claim 5, characterized in that: The number of the equipotential shielding high-value resistors is 9.

7. A low-leakage constant current source, characterized in that: It includes the equipotential shielding voltage divider according to any one of claims 5 to 6, as well as resistor R1, resistor R2, resistor R3, resistor R4, resistor R5, resistor R6, a filter circuit, operational amplifier OP3, and operational amplifiers OP1 and OP2 with the in-phase input terminals grounded; The inverting input terminal of operational amplifier OP1 is connected to one ends of resistor R1, resistor R3, and resistor R6; The other end of resistor R1 is connected to the power input terminal En; The other end of resistor R3 is connected to the output terminal of operational amplifier OP1 and the high end of the voltage divider of the equipotential shielding voltage divider; The other end of resistor R6 is connected to the output terminal of operational amplifier OP2 and one end of resistor R4; The other end of resistor R4 is connected to the inverting input terminal of operational amplifier OP2 and one end of resistor R5; The other end of resistor R5 is connected to the output terminal of operational amplifier OP3, one end of the filter circuit, and one end of resistor R2; The other end of resistor R2 is connected to the inverting input terminal of operational amplifier OP3; The non-inverting input terminal of the operational amplifier OP3 is connected to the other end of the filter circuit and the low end of the equipotential shielding voltage divider. The low end of the voltage divider is connected to the power supply output terminal U0 and is used to connect the load resistor RL.

Images