Driving circuit applied to rubidium releasing agent

Abstract

The invention relates to a driving circuit applied to a rubidium releasing agent.The driving circuit comprises a multi-signal collecting circuit, a power voltage adjusting circuit, an instruction generating circuit, a working mode switching circuit, a voltage / current converting circuit, a system state indicating circuit and an upper computer. A rubidium releasing agent is rapidly heated, driving current is set in two modes of manual adjustment and upper computer instruction, the stability and precision of the driving current are improved by collecting signals of output current and conducting closed-loop control, a power supply unit of a circuit is automatically adjusted through a digital potentiometer, the power consumption of the driving circuit is effectively reduced, and the reliability of the driving circuit is improved. And stable work when the driving current changes in a large range is realized. The circuit is also suitable for other large-current constant-current receiver circuits.

Description

Technical Field

[0001] The invention belongs to the technical field of inertial measurement sensors, in particular to a driving circuit applied to a rubidium releaser. Background Art

[0002] After nearly three decades of development, inertial sensors based on atomic interferometry have moved from the laboratory to the outdoors, showing great application potential in the fields of geodesy, geophysics, inertial navigation, etc. The primary technology for achieving atomic interferometry is to prepare a sufficient number of atoms and slow down and capture the vacuum atoms by cooling the laser. Taking the rubidium atom interferometer as an example, the atoms in the vacuum are mainly generated by the rubidium atom gas chamber or the rubidium atom releaser.

[0003] The rubidium atom gas chamber is mainly composed of filled rubidium atoms and a sealed glass container. When in use, the glass needs to be broken to release the rubidium atoms. The required rubidium atoms are generated by a rubidium generator dispenser containing rubidium compounds and sustained-release agents. The rubidium atom release agent is ionized and released by an external driving current, and the release amount is controlled by the size of the driving current. The stability of the rubidium atom release amount is closely related to the final measurement accuracy. Therefore, a high-precision rubidium release agent drive circuit that generates a constant heating current needs to be designed.

[0004] The currently used rubidium releaser driving circuit sets the working current to enable the atom interferometer to prepare a sufficient number of atoms in the working state. This process takes a long time and is not conducive to the rapid startup of the device. At the same time, the open-loop voltage-controlled current source circuit architecture is not conducive to improving the accuracy of the rubidium atomic flux. In the case of large output current, the heat loss of the power MOSFET in the driving circuit increases accordingly, causing the device to heat up and affect the long-term working stability of the rubidium atom interferometer. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and propose a driving circuit applied to a rubidium releaser to achieve the adjustment of the driving current within a larger output range; at the same time, a small current heat preservation measure is added to achieve the rapid temperature rise of the rubidium releaser, and the driving current is set in two modes: manual adjustment and host computer instruction. The signal of the output current is collected and closed-loop controlled to improve the stability and accuracy of the driving current. Finally, a digital potentiometer is used to automatically adjust the power supply unit of the circuit, effectively reducing the power consumption of the driving circuit, and achieving stable operation when the driving current changes over a large range.

[0006] The present invention solves the technical problem by adopting the following technical solutions:

[0007] A driving circuit for a rubidium releaser comprises a multi-signal acquisition circuit, a voltage / current conversion circuit, an instruction generation circuit, a working mode switching circuit, a voltage / current conversion circuit, a system status indication circuit and a host computer, wherein the instruction generation circuit and the host computer are connected to each other, the instruction generation circuit is respectively connected to the working mode switching circuit and the system status indication circuit, the working mode switching circuit, the voltage / current conversion circuit, the multi-signal acquisition circuit and the instruction generation circuit are connected in series, and the voltage / current conversion circuit, the power supply voltage adjustment circuit and the multi-signal acquisition circuit are connected in series.

[0008] Moreover, the instruction generation circuit, the working mode switching circuit, the multi-signal acquisition circuit, the system status indication circuit and the host computer are composed of an analog-to-digital converter with a microcontroller circuit as the core, an analog switch and a host computer display and control program, and the voltage / current conversion circuit for generating a constant current for heating is realized by a constant current receiver current sink circuit.

[0009] Moreover, the working mode switching circuit includes a CMOS SPDT switch ADG1419 K1 and a CMOS SPDT switch ADG1419 K2, wherein the SB pin of the CMOS SPDT switch ADG1419 K1 inputs a working current setting signal, the IN pin of the CMOS SPDT switch ADG1419 K1 inputs a control instruction 1 signal, the D pin of the CMOS SPDT switch ADG1419 K1 outputs a heating current setting signal, the SA pin of the CMOS SPDT switch ADG1419 K1 is connected to the D pin of the CMOS SPDT switch ADG1419 K2, the SB pin of the CMOS SPDT switch ADG1419 K2 inputs a host computer instruction setting signal, the IN pin of the CMOS SPDT switch ADG1419 K2 inputs a control instruction 2 signal, and the SA pin of the CMOS SPDT switch ADG1419 K2 outputs a warming current setting signal.

[0010] Moreover, the voltage / current conversion circuit includes an operational amplifier N2A, a resistor R1, a resistor R2, a resistor R3, a resistor R7, a capacitor C2 and a MOSFET V1, wherein a set value signal is input to pin 3 of the operational amplifier N2A, pin 8 of the operational amplifier N2A is connected to a power supply, pin 4 of the operational amplifier N2A is grounded, pin 2 of the operational amplifier N2A is respectively connected to one end of the resistor R2 and the resistor R7, the other end of the resistor R2 is connected to one end of the capacitor C2, the other end of the capacitor C2 is connected to pin 1 of the operational amplifier N2A and one end of the resistor R1, the other end of the resistor R1 is connected to the gate of the MOSFET V1, the other end of the resistor R7 is respectively connected to one end of the resistor R3 and the source of the MOSFET V1, and the drain of the MOSFET V1 is connected to the rubidium generator dispenser.

[0011] Moreover, the multi-signal acquisition circuit includes a resistor R16, a resistor R17, a resistor R18, a resistor R19, a capacitor C11, a capacitor C12, a capacitor 13, a capacitor C14, a capacitor 15, a capacitor C16, a capacitor C17, a capacitor C18 and a multi-channel analog-to-digital converter N4, wherein the UA signal is connected to one end of the resistor R16, the other end of the resistor R16 is respectively connected to the capacitor C11, the capacitor C12 and the AIN0 pin of the multi-channel analog-to-digital converter N4, and the other ends of the capacitor C11 and the capacitor C12 are grounded; wherein the UB signal is connected to one end of the resistor R17, the other end of the resistor R17 is respectively connected to the capacitor C11, the capacitor C12 and the AIN0 pin of the multi-channel analog-to-digital converter N4 C13, capacitor C14 and the AIN1 pin of the multi-channel analog-to-digital converter N4, and the other ends of capacitor C13 and capacitor C14 are grounded; wherein the UC signal is connected to one end of resistor R18, and the other end of resistor R18 is respectively connected to capacitor C15, capacitor C16 and the AIN2 pin of the multi-channel analog-to-digital converter N4, and the other ends of capacitor C15 and capacitor C16 are grounded; wherein the UD signal is connected to one end of resistor R19, and the other end of resistor R19 is respectively connected to capacitor C17, capacitor C18 and the AIN3 pin of the multi-channel analog-to-digital converter N4, and the other ends of capacitor C17 and capacitor C18 are grounded.

[0012] Moreover, the UA signal is the power input terminal of the Rb rubidium generator dispenser, the UB signal is the gate of the MOSFET of the current source circuit, the UC signal is the series connection terminal of the monitoring resistor and the drain of the MOSFET, the UB signal is the gate of the MOSFET of the current source circuit, the UC signal is the source of the MOSFET of the current source circuit, and the UD signal represents the power supply voltage of the rubidium generator dispenser.

[0013] The advantages and positive effects of the present invention are:

[0014] The present invention constructs a driving circuit for rubidium releaser through a multi-signal acquisition circuit, an instruction generation circuit, a working mode switching circuit, a voltage / current conversion circuit, a system state indication circuit and a host computer. The drive current is adjusted within a larger output range, a small current insulation measure is added, and the rubidium releaser is quickly heated. The drive current is set in two modes: manual adjustment and host computer instruction. The signal of the output current is collected and closed-loop controlled to improve the stability and accuracy of the drive current. The power supply unit of the circuit is automatically adjusted by a digital potentiometer, which effectively reduces the power consumption of the drive circuit and realizes stable operation when the drive current changes over a large range. The circuit is also suitable for other large current constant current receiver circuits. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the structure of the rubidium generator dispenser;

[0016] Figure 2 It is a system schematic diagram of the rubidium source heating device of the present invention;

[0017] Figure 3 It is a schematic diagram of the switching function of the constant current source working mode of the present invention;

[0018] Figure 4 This is a circuit diagram of a constant current receiver of the present invention;

[0019] Figure 5 This is a schematic diagram of the data acquisition and system working status indication circuit of the present invention;

[0020] Figure 6 FIG. 4 is a schematic diagram of a power supply voltage adjustment circuit according to the present invention.

[0021] Description of labels:

[0022] 1. Cathode of the device; 2. Alkali metal-doped organic layer; 3. Anode; 4. Glass medium. DETAILED DESCRIPTION

[0023] The present invention is further described in detail below with reference to the accompanying drawings.

[0024] like Figure 1 The figure shows the structure and scheme of the rubidium generator dispenser, which indicates that the rubidium generator dispenser in the atomic interferometer includes the cathode 1, the alkali metal doped organic layer 2, the anode 3, and the glass medium 4. When the dispenser is heated with a constant current, the amount of evaporated alkali metal atoms increases steadily over time.

[0025] A driving circuit for a rubidium release agent, such as Figure 2 As shown, it includes a multi-signal acquisition circuit, a voltage / current conversion circuit, an instruction generation circuit, a working mode switching circuit, a voltage / current conversion circuit, a system status indication circuit and a host computer, wherein the instruction generation circuit and the host computer are connected to each other, the instruction generation circuit is respectively connected to the working mode switching circuit and the system status indication circuit, and the working mode switching circuit, the voltage / current conversion circuit, the multi-signal acquisition circuit and the instruction generation circuit are connected in series. The instruction generation circuit, the working mode switching circuit, the multi-signal acquisition circuit, the system status indication circuit and the host computer are composed of an analog-to-digital converter with a microcontroller circuit as the core, an analog switch and a host computer display control program, and the voltage / current conversion circuit that generates a constant current for heating is realized by a constant current receiver current sink circuit.

[0026] like Figure 3As shown, the working mode switching circuit includes a CMOS SPDT switch ADG1419 K1 and a CMOS SPDT switch ADG1419 K2, wherein the SB pin of the CMOS SPDT switch ADG1419 K1 inputs a working current setting signal, the IN pin of the CMOS SPDT switch ADG1419 K1 inputs a control instruction 1 signal, the D pin of the CMOS SPDT switch ADG1419K1 outputs a heating current setting signal, the SA pin of the CMOS SPDT switch ADG1419 K1 is connected to the D pin of the CMOS SPDT switch ADG1419 K2, the SB pin of the CMOS SPDT switch ADG1419 K2 inputs a host computer instruction setting signal, the IN pin of the CMOS SPDT switch ADG1419K2 inputs a control instruction 2 signal, and the SA pin of the CMOS SPDT switch ADG1419 K2 outputs a holding current setting signal.

[0027] The working mode switching circuit can realize that when the atomic interferometer is not in working state, the rubidium generator dispenser maintains a certain initial temperature, but does not generate excitation of rubidium atoms. Once the atomic interferometer enters the working mode, it can reach a stable state in a relatively short time. The present invention adopts two CMOS SPDT switches, and three working modes can be realized through the control instructions sent by the host computer: a, manual adjustment of the current value; b, the host computer automatically sets the current value; c, insulation / heating state.

[0028] like Figure 4 As shown, the voltage / current conversion circuit includes an operational amplifier N2A, a resistor R1, a resistor R2, a resistor R3, a resistor R7, a capacitor C2 and a MOSFET V1, wherein a set value signal is input to pin 3 of the operational amplifier N2A, pin 8 of the operational amplifier N2A is connected to a power supply, pin 4 of the operational amplifier N2A is grounded, pin 2 of the operational amplifier N2A is respectively connected to one end of the resistor R2 and one end of the resistor R7, the other end of the resistor R2 is connected to one end of the capacitor C2, the other end of the capacitor C2 is connected to pin 1 of the operational amplifier N2A and one end of the resistor R1, the other end of the resistor R1 is connected to the gate of the MOSFET V1, the other end of the resistor R7 is respectively connected to one end of the resistor R3 and the source of the MOSFET V1, and the drain of the MOSFET V1 is connected to the rubidium generator dispenser.

[0029] The rubidium generation and distribution device is connected to the source of the MOSFET at the output end of the power supply and the constant current receiver circuit, and a current detection resistor is added on the ground side to form a constant current circuit in the direction of current inflow. The current value is proportional to the set voltage and inversely proportional to the detection resistor. Since the detection resistor directly affects the accuracy of the rubidium source heating circuit, it causes resistance temperature drift when working at a high current for a long time. Therefore, a low temperature coefficient and high power detection resistor is required in the design, which can be achieved by connecting multiple power resistors in series and parallel when necessary.

[0030] like Figure 5 As shown, the multi-signal acquisition circuit includes a resistor R16, a resistor R17, a resistor R18, a resistor R19, a capacitor C11, a capacitor C12, a capacitor 13, a capacitor C14, a capacitor 15, a capacitor C16, a capacitor C17, a capacitor C18 and a multi-channel analog-to-digital converter N4, wherein the UA signal is connected to one end of the resistor R16, the other end of the resistor R16 is respectively connected to the capacitor C11, the capacitor C12 and the AIN0 pin of the multi-channel analog-to-digital converter N4, and the other ends of the capacitor C11 and the capacitor C12 are grounded; wherein the UB signal is connected to one end of the resistor R17, the other end of the resistor R17 is respectively connected to the capacitor C 13, capacitor C14 and the AIN1 pin of the multi-channel analog-to-digital converter N4, and the other ends of capacitor C13 and capacitor C14 are grounded; wherein the UC signal is connected to one end of resistor R18, and the other end of resistor R18 is respectively connected to capacitor C15, capacitor C16 and the AIN2 pin of the multi-channel analog-to-digital converter N4, and the other ends of capacitor C15 and capacitor C16 are grounded; wherein the UD signal is connected to one end of resistor R19, and the other end of resistor R19 is respectively connected to capacitor C17, capacitor C18 and the AIN3 pin of the multi-channel analog-to-digital converter N4, and the other ends of capacitor C17 and capacitor C18 are grounded.

[0031] The multi-signal acquisition circuit uses a multi-channel analog-to-digital converter to digitize the analog electrical signal, thereby obtaining real-time information of the key working points of the driving circuit of the rubidium releaser, and thus generating a closed-loop control of the power supply voltage to achieve the purpose of reducing the power consumption of the circuit. In the figure, UA is the power input terminal of the Rb generator dispenser. Under normal circumstances, the voltage signal can be the power supply of the line, or it can be generated by secondary conversion of the power supply through a step-down converter, and connected to one end of the rubidium generator dispenser at the same time; UB is the S pole of the MOSFET of the current source circuit, and is connected to the other end of the rubidium generator dispenser at the same time. The heating current enters the control circuit from this point after passing through the rubidium generator dispenser from the power supply; UC is the monitoring resistor and the D pole of the MOSFET in series. Therefore, the voltage values ​​of these three points represent the current source power supply voltage, the S and D pole voltages of the MOSFET, and the value of the distributor drive current can also be calculated.

[0032] like Figure 6The schematic diagram of the power supply voltage adjustment circuit is shown, which can reduce the heat loss of the circuit and improve the reliability of components. According to the set current, the actual output current and the source-drain voltage difference of the MOSFET, the Uds of the MOSFET is reduced as much as possible under the premise of ensuring that the output current meets the requirements, thereby reducing the power loss of the field effect tube itself, reducing heat generation, and improving reliability. The present invention uses a programmable chip FPGA, a multi-channel analog-to-digital conversion chip, an output voltage adjustable voltage stabilizing chip and a digital potentiometer as core components to achieve the above functions. Among them, N2 is a step-down converter that can continuously output 10A current; R15 uses a 256-tap, low-drift digital potentiometer with a temperature coefficient of less than 5ppm / ℃, and uses a 3-wire SPI communication interface; N4 is a 24-bit multi-channel analog-to-digital converter that can realize 4-channel differential or 8-channel single-point input, with a data output rate of up to 30SPS, and a built-in low-noise, variable-gain operational amplifier that can communicate with a microprocessor through a 2-wire SPI interface. The specific implementation process is step 1: receiving the current setting command, adjusting +Vp to the maximum output value; step 2: after the output current is stable, if Uds is greater than 0.5V, slowly reduce +Vp until the appropriate power supply voltage is reached. In this process, N4 will collect the voltage signals of each point in the form of digital quantities and send them to FPGA. FPGA will adjust the setting value of R15 digital potentiometer according to the rubidium source heating current and MOSFET voltage signal, and adjust +Vp according to the voltage divider ratio of R15.

[0033] The working method of the present invention is:

[0034] When the controller is correctly connected to the rubidium generator dispenser, the Cathode of the rubidium generator dispenser is connected to the output end of the step-down transformer N2, and the Anode is connected to the drain of MOSFETV1. The set value of the heating current is adjusted by sending instructions from the host computer or manually adjusting the potentiometer to achieve the insulation function. In the standby state, the controller outputs a small current, and in the working state, it outputs a larger current according to demand, so that the working state can be quickly reached after the system is started. When working, the electrical signal of the Dispenser power output stage is collected and calculated in real time through the host computer and the multi-signal acquisition circuit (ADC chip N4) module, and the N2 output voltage Vp is dynamically adjusted through the digital potentiometer R15 to reduce the heat loss of the heating power MOSFET. High-precision Dispenser heating current control is achieved by controlling the voltage-current conversion circuit (operational amplifier N2).

[0035] It should be emphasized that the embodiments described in the present invention are illustrative rather than restrictive. Therefore, the present invention includes but is not limited to the embodiments described in the specific implementation manner. Any other implementation manners derived by those skilled in the art based on the technical solution of the present invention also fall within the scope of protection of the present invention.

Claims

1. A driving circuit for a rubidium releaser, characterized in that: It includes a multi-signal acquisition circuit, an instruction generation circuit, a working mode switching circuit, a voltage / current conversion circuit, a power supply voltage adjustment circuit, a system status indication circuit and a host computer, wherein the instruction generation circuit and the host computer are connected to each other, the instruction generation circuit is respectively connected to the working mode switching circuit and the system status indication circuit, the working mode switching circuit, the voltage / current conversion circuit, the multi-signal acquisition circuit and the instruction generation circuit are connected in series, and the voltage / current conversion circuit, the power supply voltage adjustment circuit and the multi-signal acquisition circuit are connected in series.

2. The driving circuit for rubidium release agent according to claim 1, characterized in that: The command generation circuit, the working mode switching circuit, the multi-signal acquisition circuit, the system status indication circuit and the host computer are composed of an analog-to-digital converter with a microcontroller circuit as the core, an analog switch and a host computer display and control program. The voltage / current conversion circuit for generating a constant current for heating is realized by a constant current receiver current sink circuit.

3. The driving circuit for rubidium release agent according to claim 1, characterized in that: The working mode switching circuit includes a CMOS SPDT switch ADG1419 K1 and a CMOS SPDT switch ADG1419 K2, wherein the SB pin of the CMOS SPDT switch ADG1419 K1 inputs a working current setting signal, the IN pin of the CMOS SPDT switch ADG1419 K1 inputs a control instruction 1 signal, the D pin of the CMOS SPDT switch ADG1419 K1 outputs a heating current setting signal, the SA pin of the CMOS SPDT switch ADG1419 K1 is connected to the D pin of the CMOS SPDT switch ADG1419 K2, the SB pin of the CMOS SPDT switch ADG1419K2 inputs a host computer instruction setting signal, the IN pin of the CMOS SPDT switch ADG1419 K2 inputs a control instruction 2 signal, and the SA pin of the CMOS SPDT switch ADG1419 K2 outputs a warming current setting signal.

4. The driving circuit for rubidium release agent according to claim 1, characterized in that: The voltage / current conversion circuit includes an operational amplifier N2A, a resistor R1, a resistor R2, a resistor R3, a resistor R7, a capacitor C2 and a MOSFET V1, wherein a set value signal is input to pin 3 of the operational amplifier N2A, pin 8 of the operational amplifier N2A is connected to a power supply, pin 4 of the operational amplifier N2A is grounded, pin 2 of the operational amplifier N2A is respectively connected to one end of the resistor R2 and one end of the resistor R7, the other end of the resistor R2 is connected to one end of the capacitor C2, the other end of the capacitor C2 is connected to pin 1 of the operational amplifier N2A and one end of the resistor R1, the other end of the resistor R1 is connected to the gate of the MOSFET V1, the other end of the resistor R7 is respectively connected to one end of the resistor R3 and the source of the MOSFET V1, and the drain of the MOSFET V1 is connected to a rubidium generator dispenser.

5. The driving circuit for rubidium release agent according to claim 1, characterized in that: The multi-signal acquisition circuit includes a resistor R16, a resistor R17, a resistor R18, a resistor R19, a capacitor C11, a capacitor C12, a capacitor 13, a capacitor C14, a capacitor 15, a capacitor C16, a capacitor C17, a capacitor C18 and a multi-channel analog-to-digital converter N4, wherein the UA signal is connected to one end of the resistor R16, the other end of the resistor R16 is respectively connected to the capacitor C11, the capacitor C12 and the AIN0 pin of the multi-channel analog-to-digital converter N4, and the other ends of the capacitors C11 and C12 are grounded; wherein the UB signal is connected to one end of the resistor R17, the other end of the resistor R17 is respectively connected to the capacitors C 13, capacitor C14 and the AIN1 pin of the multi-channel analog-to-digital converter N4, and the other ends of capacitor C13 and capacitor C14 are grounded; wherein the UC signal is connected to one end of resistor R18, and the other end of resistor R18 is respectively connected to capacitor C15, capacitor C16 and the AIN2 pin of the multi-channel analog-to-digital converter N4, and the other ends of capacitor C15 and capacitor C16 are grounded; wherein the UD signal is connected to one end of resistor R19, and the other end of resistor R19 is respectively connected to capacitor C17, capacitor C18 and the AIN3 pin of the multi-channel analog-to-digital converter N4, and the other ends of capacitor C17 and capacitor C18 are grounded.

6. The driving circuit for rubidium release agent according to claim 5, characterized in that: The UA signal is the power input terminal of the Rb rubidium generator dispenser, the UB signal is the gate of the current source circuit MOSFET, the UC signal is the source of the current source circuit MOSFET, and the UD signal represents the power supply voltage of the rubidium generator dispenser.

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