CN209841948U - Adjustable Hall voltage sensor - Google Patents

Abstract

The utility model discloses a hall voltage sensor with adjustable, including direct current voltage input circuit, hall element, working current circuit, vice limit electric current forming circuit, adjustable proportion circuit, voltage input circuit is used for being passed the voltage conversion and being primary side current, primary side current passes through primary side coil forms primary side magnetic field, hall element includes primary side coil and vice limit coil, the working current circuit is used for providing working current, vice limit electric current forming circuit is used for enlargiing hall voltage and converts into vice limit electric current, vice limit electric current passes through vice limit coil forms vice limit magnetic field, adjustable proportion circuit is used for adjusting the conveying proportion, makes output voltage adjustable, the utility model provides an adjustable hall voltage sensor has that sensing precision is high, the continuous adjustable characteristics of conveying proportion.

Description

Adjustable Hall Voltage Sensor

technical field

The utility model relates to a sensor, in particular to an adjustable Hall voltage sensor.

Background technique

At present, there are two types of sensors used for DC voltage isolation at home and abroad. One is the photoelectric sensor based on the photoelectric effect. This type of sensor has high sensing accuracy and good linearity under the condition of constant ambient temperature, but when the ambient temperature When changing, the dark current and photocurrent of the photosensitive device will change with the change of temperature, so only DC isolation can be achieved, and it is difficult to achieve the purpose of high-precision isolation transmission and detection of DC voltage. The other type is the Hall voltage sensor, which has the characteristics of high sensing accuracy, good linearity, and small temperature drift. The characteristics of the magnetic balance principle based on the Hall effect are: First, due to the magnetic balance principle, it can be The output current can accurately reflect the current value of the primary side, and the output voltage can accurately reflect the voltage value of the primary side. Therefore, the sensor developed by this principle can theoretically have the characteristics of high sensing accuracy and good linearity. , The second is the high isolation between the output and the input, which is very conducive to electrical isolation.

In a modern system that uses computers for 4-remote monitoring (remote control, remote adjustment, remote signaling, and telemetry), an electrical isolation test is required between the industrial computer and the controlled equipment in the monitoring system to ensure the safe and reliable operation of the industrial computer. Among them, the DC voltage isolation detection is usually realized by the Hall voltage sensor. The Hall voltage sensor not only has high sensing accuracy and good linearity, but also has small temperature drift, and its sensing accuracy and linearity change very little in the temperature range of -40°C to 75°C. Therefore, it has been widely used in isolation detection and isolation monitoring technology. However, in the detection system of the industrial computer, since there are many voltages to be detected, and the voltage values are different, even greatly different, the requirements for the input voltage range of the industrial computer are certain. In this case, if the output voltage of the sensor is the same as the input voltage The ratio (transmission ratio) of the sensor is fixed, so in some cases (the voltage is too high or too low), the output voltage of the sensor cannot meet the requirements of the industrial computer for the input voltage. In order to meet the requirements of the industrial computer for the input voltage, the output voltage of the sensor has to be reprocessed, which often reduces the accuracy.

Contents of the invention

The purpose of the present invention is to solve the problem that the transmission ratio of the detection voltage of the Hall voltage sensor in the prior art is fixed. When the detection system needs to detect many voltages and the voltage values are different, the output voltage of the sensor needs to be reprocessed. This processing The test accuracy is often reduced, so the utility model provides an adjustable Hall voltage sensor, which has the characteristics of high sensing accuracy and continuously adjustable transmission ratio.

The utility model provides technical scheme as follows:

Adjustable Hall voltage sensors, including:

A DC voltage input circuit, used to convert the transmitted voltage into a primary current, and the primary current passes through the primary coil to form a primary magnetic field;

Hall element N ₃ , the Hall element N ₃ includes a primary coil and a secondary coil;

An operating current circuit for providing an operating current;

The secondary current forming circuit is used to amplify and convert the Hall voltage into a secondary current, and the secondary current passes through the secondary coil to form a secondary magnetic field;

The adjustable ratio circuit is used to adjust the transmission ratio so that the output voltage can be adjusted.

Further, the adjustable ratio circuit includes at least one adjustable resistor R ₀₁ .

Further, the adjustable ratio circuit includes a resistor R ₀₂ and an adjustable resistor R ₀₁ , one end of the resistor R ₀₂ is connected to the secondary voltage output end, the other end of the resistor R ₀₂ is grounded, and the adjustable resistor R ₀₁ is connected in series to the voltage output end and resistor R ₀₂ .

Further, the working current circuit includes a resistor R ₄ , a positive power supply, a resistor R ₅ , and a negative power supply. Pin 1 of the Hall element N ₃ is connected to the positive power supply through the resistor R ₄ , and 3 pins of the Hall element N _{3 The} pin is connected to the negative power supply through the resistor R5.

Further, the working current circuit further includes a filter capacitor C ₃ , the positive pole of the filter capacitor C ₃ is connected to the positive power supply, and the negative pole of the filter capacitor C ₃ is connected to the negative power supply.

Further, the adjustable Hall voltage sensor also includes an offset elimination circuit for eliminating the additional voltage.

Further, the offset elimination circuit includes an operational amplifier N ₁ , a resistor R ₁ , and a resistor R ₂ , the b-cp1 end of the operational amplifier N ₁ is connected to the cp2 end of the operational amplifier N ₁ via a capacitor C ₁ , and the operational amplifier N 1 The _iput2 end of N1 is connected to pin ₂ of the Hall element N3 via _a resistor R1, the _iput1 end _of the operational amplifier N1 is connected to pin ₄ of the Hall element N3 via a resistor R2, and the _vout of the operational amplifier N1 The terminal outputs the processed signal to the secondary current forming circuit.

Further, the secondary current forming circuit includes a first transistor Q ₁ and a second transistor Q ₂ , the collector of the first transistor Q ₁ is connected to the output terminal of the offset elimination circuit, and the first transistor Q 1 The base of _a transistor Q1 is connected to the positive power supply, the emitter of the _first transistor Q1 is connected to the collector of the _second transistor _Q2 , and the emitter of the second transistor Q2 is connected to eliminate the offset At the output end of the circuit, the base of the second triode _Q2 is connected to the negative power supply, and the collector of the second triode _Q2 is connected to the signal output end.

Further, the secondary current forming circuit further includes a first switching diode D ₁ and a second switching diode D ₂ , the anode of the first switching diode D ₁ is connected to the base of the second triode Q ₂ , the first switching diode _The cathode of D1 is connected to the collector of the second transistor _Q2 , the anode of the _second switching diode D2 is connected to the collector of the second transistor _Q2 , and the cathode of the _second switching diode D2 is connected to the first transistor The base of Q ₁ , the first switching diode D ₁ and the second switching diode D ₂ are BAV99.

Compared with prior art, the beneficial effect of the present invention is:

1. The adjustable Hall voltage sensor disclosed in the utility model adopts an adjustable ratio circuit, which solves the problem that the output voltage cannot be adjusted in the prior art, and can realize continuous adjustment of the transmission ratio, and adjust the input voltage of different voltage ranges to be available. The voltage detected by the industrial computer.

2. The utility model solves the problem that the detection system needs to reprocess the output voltage of the sensor in the prior art by adopting an adjustable ratio circuit, and can realize the effect of improving the test accuracy;

_3. The utility model adopts the offset elimination circuit to eliminate the additional voltage brought by the Hall element N3 to the Hall voltage due to the unequal potential effect and many other reasons including processing, thereby improving the accuracy of the test.

4. Due to the high isolation between the output and the input of the utility model, it is very beneficial to the electrical isolation, thereby reducing the measurement error.

Description of drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention , for those skilled in the art, other drawings can also be obtained based on these drawings without creative work.

Fig. 1 is the schematic diagram of Hall effect magnetic balance in the prior art;

Fig. 2 is the functional block diagram of the adjustable Hall voltage sensor provided by the embodiment of the utility model;

Fig. 3 is the schematic diagram of the circuit connection of the adjustable proportional circuit provided by the embodiment of the present invention;

Fig. 4 is a secondary side circuit diagram of the adjustable Hall voltage sensor provided by the embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. example. Based on the embodiments of the present utility model, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

The adjustable Hall voltage sensor of the embodiment of the utility model is described below with reference to the accompanying drawings.

Fig. 1 is the principle diagram of Hall effect magnetic balance in the prior art, the magnetic flux and the secondary current I _O generated by the transmitted voltage _U1 through the primary current value IP _of the equivalent resistance R on the primary side (by the Hall voltage via the Hall voltage) When the magnetic flux generated by the secondary coil is balanced, the secondary current value I _O will accurately reflect the primary current value I _P , and the voltage drop U _O of the secondary current I _O on R ₀ will be accurately Reflecting the primary side voltage value U ₁ , this is the magnetic balance principle based on the Hall effect, which is also referred to as the magnetic balance principle or the Hall effect closed-loop principle.

Fig. 2 is the functional block diagram of the adjustable Hall voltage sensor provided by the embodiment of the present invention. The adjustable voltage sensor developed by using the magnetic balance principle based on the Hall effect and the adjustable proportional circuit includes:

A DC voltage input circuit, which is connected to the primary coil, converts the transmitted voltage into a primary current I _P , and the current passes through the primary coil to form a primary magnetic field.

Adjustable ratio circuit, the adjustable ratio circuit is connected to the secondary side voltage output terminal, so that the output voltage U _O can be continuously adjusted to meet various test requirements. Specifically, refer to Fig. 3, which is provided by the embodiment of the present invention Schematic diagram of the circuit connection of the adjustable ratio. The adjustable ratio circuit includes a resistor R ₀₂ and an adjustable resistor R _01. One end of the resistor R ₀₂ is connected to the secondary voltage output terminal, and the other end of the resistor R ₀₂ is grounded. The adjustable resistor R ₀₁ is connected in series Between the voltage output terminal and the resistor R ₀₂ , so that when the primary side magnetic flux and the secondary side magnetic flux balance, the secondary side current value I _O will accurately reflect the primary side current value I _P , and the secondary side voltage value U _O will accurately reflect Primary side voltage value U ₁ . Therefore, the purpose of adjusting the transmission ratio can be achieved by adjusting the resistance value of the adjustable resistor R ₀₁ .

The secondary current forming circuit is connected to the secondary coil to amplify and convert the Hall voltage into a secondary current I _O , and the current passes through the secondary coil to form a secondary magnetic field.

A working current circuit, the working current circuit is connected to the secondary current forming circuit, and the circuit can provide working current for the Hall element N ₃ , the secondary current forming circuit and the offset elimination circuit.

The offset elimination circuit, which is connected to the secondary current forming circuit, can eliminate the additional voltage brought by the Hall element _N3 to the Hall voltage due to the unequal potential effect and reasons including processing.

As shown in Figure 4, as a specific embodiment of the working current circuit of the present invention, the working current circuit includes a resistor R ₄ , a positive power supply, a resistor R ₅ , and a negative power supply. The working current circuit provides a working circuit for the Hall element N ₃ , The specific connection method of the circuit is as follows:

Pin 1 (VCC+) of Hall element N ₃ is connected to the positive power supply through resistor R ₄ , the positive power supply provides +15V DC voltage for the circuit, pin 3 (VCC-) of Hall element N ₃ is connected to negative power supply through resistor R ₅ power supply, the negative supply provides a DC voltage of -15V for this circuit.

In order to eliminate unnecessary AC components in the DC power supply, the working current circuit further includes a filter capacitor C ₃ , the positive pole of the filter capacitor C ₃ is connected to the positive power supply, and the negative pole of the filter capacitor C ₃ is connected to the negative power supply.

As shown in Figure 4, as a specific embodiment of the offset elimination circuit of the present invention, the offset elimination circuit includes a general-purpose operational amplifier N ₁ , a resistor _{R 1} , and a resistor R ₂ . The additional voltage brought by the bit effect and the reason including processing to the Hall voltage, the specific connection method of the circuit is as follows:

_The Vcc+ terminal of the general operational amplifier N1 is connected to the positive power supply. _The model of the general operational amplifier N1 is LM201. The positive power supply provides +15V DC voltage for the circuit. _The Vcc- terminal of the general operational amplifier N1 is connected to the negative power supply. The negative power supply provides a DC voltage of -15V for the circuit, the b _- cp1 terminal of the operational amplifier N1 is connected to the _cp2 terminal of the operational amplifier N1 through the capacitor _C1 , and the _iput2 terminal _of the operational amplifier N1 is connected to the Hall element through the resistor R1 Pin 2 of N ₃ , the iput1 terminal of operational amplifier N ₁ is connected to pin 4 of Hall element N ₃ through resistor R ₂ , and the vout terminal of operational amplifier N ₁ outputs the processed signal to the secondary current forming circuit.

For the convenience of adjusting the zero point, the offset elimination circuit also includes resistors R ₇ , R ₆ , and R ₈ . These resistors form a bias current circuit. The specific connection methods are as follows:

Pin ₁ of Hall element N3 is connected to one end of resistor _R7 , the other end of resistor _R7 is connected to one end of resistor _R6 , and the other end of resistor R6 is connected to pin ₃ of Hall element N3, resistor _R7 and resistor _R One end connected to ₆ is connected to the iput2 end of the general-purpose operational amplifier N ₁ through the resistor R ₈ .

As shown in Figure 4, as a specific embodiment of the secondary current forming circuit of the present invention, the secondary current forming circuit includes a first triode Q ₁ , a second triode Q ₂ , a resistor R ₃ and a capacitor C ₂ , The model used by the _first triode Q1 is 3904, the model used by the second triode _Q2 is 3906, the collector of the _first triode Q1 is connected to the _vout terminal of the general-purpose operational amplifier N1, and the first triode _The base of the transistor Q1 is connected to the positive power supply, the emitter of the second transistor _Q2 is connected to the _vout terminal of the operational amplifier N1, the base of the second transistor _Q2 is connected to the negative power supply, and the _first transistor Q1 The emitter of the transistor Q2 is connected to the collector of the second transistor _Q2 , the collector of the second transistor _Q2 is connected to the vout terminal, _one end of the resistor _R3 is connected to the pin ₂ of the Hall element N3 through the resistor R1, and the resistor R The other end of ₃ is connected to the vout end via capacitor C ₂ . The secondary current forming circuit is connected to the secondary coil through an operational amplifier N ₁ , amplifies the Hall voltage and converts it into a secondary current I _O , and the current passes through the secondary coil to form a secondary magnetic field.

In order to make the secondary current forming circuit work more stably, the circuit also includes a first switching diode D ₁ and a second switching diode D ₂ , the type of the switching diode is BAV99, and the anode of the first switching diode D ₁ is connected to the second and third The base of the transistor _Q2 , the cathode of the _first switching diode D1 is connected to the collector of the second transistor _Q2 , the anode of the _second switching diode D2 is connected to the collector of the second transistor _Q2 , the second The cathode of the _second switching diode D2 is connected to the base of the _first triode Q1.

The above are only examples of the present application, and are not intended to limit the present application. For those skilled in the art, various modifications and changes may occur in this application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the scope of the claims of the present application.

Claims (9)

1. The adjustable Hall voltage sensor is characterized in that, comprising: A DC voltage input circuit for converting the transmitted voltage into a primary current, and the primary current passes through the primary coil to form a primary magnetic field; Hall element N ₃ , the Hall element N ₃ includes a primary coil and a secondary coil; An operating current circuit for providing an operating current; The secondary current forming circuit is used to amplify and convert the Hall voltage into a secondary current, and the secondary current passes through the secondary coil to form a secondary magnetic field; The adjustable ratio circuit is used to adjust the transmission ratio so that the output voltage can be adjusted. 2 . The adjustable Hall voltage sensor according to claim 1 , wherein the adjustable ratio circuit includes at least one adjustable resistor R ₀₁ . 3. The adjustable Hall voltage sensor according to claim 1, wherein the adjustable ratio circuit comprises a resistor R ₀₂ and an adjustable resistor R ₀₁ , one end of the resistor R ₀₂ is connected to the secondary voltage output terminal, and the resistor The other end of R ₀₂ is grounded, and the adjustable resistor R ₀₁ is connected in series between the voltage output terminal and the resistor R ₀₂ . 4. The adjustable Hall voltage sensor according to claim ₁ , characterized in that, the working current circuit includes a resistor R4, a positive power supply, a resistor R5, and a negative power supply, and pin _{1 of} the Hall element N3 passes through the _The resistor R4 is connected to the positive power supply, and pin ₃ of the Hall element _N3 is connected to the negative power supply through the resistor R5. 5. The adjustable Hall voltage sensor according to claim 4, wherein the working current circuit further comprises a filter capacitor C ₃ , the positive pole of the filter capacitor C ₃ is connected to a positive power supply, and the filter capacitor C ₃ Connect the negative pole to the negative power supply. 6. The adjustable Hall voltage sensor according to claim 1, characterized in that, the adjustable Hall voltage sensor further comprises an offset elimination circuit for eliminating the additional voltage. 7. The adjustable Hall voltage sensor according to claim 6, wherein the offset elimination circuit includes an operational amplifier N ₁ , a resistor R ₁ , and a resistor R ₂ , and the b-cp1 terminal of the operational amplifier N _{1 The} cp2 end of the operational amplifier N1 is connected through the capacitor _C1 , the _iput2 end of the operational amplifier N1 is connected to the pin _{2 of} the Hall element N3 through the resistor R1, and the _iput1 end _of the operational amplifier N1 is connected through the resistor R2 pin ₄ of the hall element N3, and the _vout terminal of the operational amplifier N1 outputs the processed signal to the secondary current forming circuit. 8. The adjustable Hall voltage sensor according to claim 1, wherein the secondary current forming circuit comprises a first triode Q ₁ and a second triode Q ₂ , the first triode _The collector of the transistor Q1 is connected to the output terminal of the offset elimination circuit, the base of the _first transistor Q1 is connected to the positive power supply, and the emitter of the _first transistor Q1 is connected to the second transistor _Q2 The collector of the second transistor Q2 is connected to the output terminal of the offset elimination circuit, the base of the second transistor _Q2 is connected to the negative power supply, and the collector of the _second transistor _Q2 is connected to the signal output. 9. The adjustable Hall voltage sensor according to claim 8, wherein the secondary current forming circuit further comprises a first switching diode D ₁ and a second switching diode D ₂ , the first switching diode D ₁ The anode is connected to the base of the second transistor _Q2 , the cathode of the _first switching diode D1 is connected to the collector of the second transistor _Q2 , and the anode of the _second switching diode D2 is connected to the second transistor _Q2 The collector and the cathode of the _second switching diode D2 are connected to the base of the _first triode Q1, and the _first switching diode D1 and the _second switching diode D2 are BAV99.