Direction switching device of constant current source circuit and protection system thereof

Abstract

The invention discloses a direction switching device of a constant current source circuit and a protection system of the constant current source circuit, and belongs to the technical field of power electronics, the direction switching device comprises a PCB, the constant current source circuit, a phase inverter and an analog switch are arranged on the PCB, and the analog switch performs positive and negative switching on power supply voltage of the constant current source circuit through the phase inverter. The direction switching device achieves the purpose of switching the direction of the constant current source circuit by changing the power supply voltage of the constant current source circuit. According to the direction switching device, the direction of the constant current source circuit can be switched only by using one analog switch, so that the number of wires of the direction switching device of the constant current source circuit on a PCB (Printed Circuit Board) can be obviously reduced, and weak current signals output by the constant current source circuit do not need to pass through via holes in the PCB; therefore, the electric leakage phenomenon of the direction switching device of the constant current source circuit on the PCB can be avoided.

Description

Technical Field

[0001] The present invention relates to the field of power electronics technology, and particularly relates to a direction switching device for a constant current source circuit and a protection system for a constant current source circuit. Background Art

[0002] Due to the advantages of fast response speed and high constant current accuracy of the constant current source circuit, the constant current source circuit has been widely applied in real life. Please refer to Figure 1 , Figure 1 which is a structural diagram of a direction switching device for a constant current source circuit in the prior art. When the first analog switch is switched to the constant current source circuit and the second analog switch is switched to the power ground at the same time, a positive reference voltage is provided to the constant current source circuit; when the first analog switch is switched to the power ground and the second analog switch is switched to the constant current source circuit at the same time, a negative reference voltage is provided to the constant current source circuit. In the Figure 1 shown direction switching device, two sets of analog switches are used to switch the direction of the constant current source circuit, which will result in a large number of traces on the PCB (Printed Circuit Board) and increase the number of vias on the PCB. Once the weak current signal output by the constant current source circuit passes through the vias on the PCB, a leakage phenomenon will occur on the PCB, posing a high safety hazard. Currently, there is no relatively effective solution to this technical problem.

[0003] Therefore, it can be seen that how to avoid the leakage phenomenon generated by the direction switching device of the constant current source circuit on the PCB is a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a direction switching device for a constant current source circuit and a protection system for a constant current source circuit to solve the technical problem that the direction switching device of the constant current source circuit in the prior art is prone to leakage on the PCB due to the large number of traces. The specific solutions are as follows:

[0005] To solve the above technical problem, the present invention provides a direction switching device for a constant current source circuit, including: a PCB, on which a constant current source circuit, an inverter, and an analog switch are arranged, and the analog switch switches the positive and negative of the supply voltage of the constant current source circuit through the inverter.

[0006] Preferably, the inverter includes a single operational amplifier chip, a first resistor, a second resistor, a third resistor, a fourth resistor, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, and a sixth capacitor;

[0007] Among them, the first end of the first capacitor is connected to the first end of the first resistor, the second end of the first resistor is respectively connected to the first end of the third resistor and the second end of the single operational amplifier chip, the fourth end of the single operational amplifier chip is respectively connected to the first end of the second resistor, the first end of the second capacitor and the first end of the third capacitor, the second end of the third resistor is respectively connected to the first end of the sixth capacitor and the sixth end of the single operational amplifier chip, and the seventh end of the single operational amplifier chip is respectively connected to the first end of the fourth capacitor, the first end of the fifth capacitor and the first end of the fourth resistor;

[0008] Correspondingly, the first end of the first capacitor is used to receive the first preset voltage output by the power supply chip, the first end of the sixth capacitor is used to receive the second preset voltage, the second end of the fourth resistor is used to receive the third preset voltage, the second end of the second resistor is used to receive the fourth preset voltage, and the second ends of the first capacitor, the second capacitor, the third capacitor, the fourth capacitor, the fifth capacitor and the sixth capacitor are all grounded.

[0009] Preferably, the power supply chip is specifically an ADI power supply chip.

[0010] Preferably, it further includes:

[0011] A power supply filtering circuit for filtering the power supply voltage of the ADI power supply chip.

[0012] Preferably, the analog switch includes: an ADI analog switch chip, a fifth resistor, a sixth resistor, a seventh resistor, a seventh capacitor, an eighth capacitor, a ninth capacitor, a tenth capacitor and an eleventh capacitor;

[0013] Among them, the first end of the ADI analog switch chip is respectively connected to the first end of the fifth resistor and the first end of the seventh capacitor, the seventh end of the ADI analog switch chip is respectively connected to the first end of the sixth resistor, the first end of the eighth capacitor and the first end of the ninth capacitor, and the fourth end of the ADI analog switch chip is respectively connected to the first end of the seventh resistor, the first end of the tenth capacitor and the first end of the eleventh capacitor;

[0014] Correspondingly, the second ends of the fifth resistor, the seventh capacitor, the eighth capacitor, the ninth capacitor, the tenth capacitor, and the eleventh capacitor are all grounded. The first end of the ADI analog switch chip is used to receive a preset reference voltage, the second end of the ADI analog switch chip is used to receive a first preset voltage, the eighth end of the ADI analog switch chip is used to receive a second preset voltage, the second end of the seventh resistor is used to receive a third preset voltage, the second end of the sixth resistor is used to receive a fourth preset voltage, and the sixth end of the ADI analog switch chip is used to receive a target switching signal.

[0015] Preferably, it further includes:

[0016] A signal acquisition circuit connected to the constant current source circuit for acquiring signals.

[0017] Preferably, the signal acquisition circuit includes: a standard resistor, a sampling resistor, and an ADC for signal conversion of the signals acquired by the standard resistor and the sampling resistor;

[0018] Wherein, the second end of the standard resistor is used to receive a target input signal, the first end of the standard resistor is connected to the first end of the sampling resistor, and the fourth end of the sampling resistor is grounded.

[0019] Preferably, the constant current source circuit includes: a first dual operational amplifier chip, a second dual operational amplifier chip, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, an eighteenth resistor, a nineteenth resistor, a twentieth resistor, a twelfth capacitor, a thirteenth capacitor, a fourteenth capacitor, a fifteenth capacitor, a sixteenth capacitor, a seventeenth capacitor, an eighteenth capacitor, a nineteenth capacitor, a twentieth capacitor, and a twenty-first capacitor;

[0020] Among them, the first end of the first dual operational amplifier chip is connected to the first end of the tenth resistor and the first end of the fifteenth resistor, the second end of the first dual operational amplifier chip is connected to the second end of the tenth resistor, the third end of the first dual operational amplifier chip is respectively connected to the first end of the twelfth resistor and the first end of the thirteenth resistor, the fourth end of the first dual operational amplifier chip is respectively connected to the second end of the fourteenth capacitor, the second end of the fifteenth capacitor and the second end of the eleventh resistor, the fifth end of the first dual operational amplifier chip is respectively connected to the second end of the twelfth resistor, the second end of the thirteenth resistor and the first end of the twentieth capacitor, the sixth end of the first dual operational amplifier chip is connected to the second end of the ninth resistor, the seventh end of the first dual operational amplifier chip is respectively connected to the first end of the ninth resistor and the second end of the seventeenth resistor, the eighth end of the first dual operational amplifier chip is respectively connected to the first end of the eighth resistor, the first end of the twelfth capacitor and the first end of the thirteenth capacitor, the first end of the second dual operational amplifier chip is connected to the first end of the twentieth resistor and the first end of the twentieth capacitor, the second end of the second dual operational amplifier chip is respectively connected to the seventh end of the second dual operational amplifier chip, the first end of the sixteenth resistor, the second end of the twentieth capacitor and the second end of the twenty-first capacitor, the first end of the twenty-first capacitor is connected to the second end of the twentieth resistor, the fourth end of the second dual operational amplifier chip is respectively connected to the second end of the eighteenth capacitor, the second end of the nineteenth capacitor and the second end of the nineteenth resistor, the fifth end of the second dual operational amplifier chip is respectively connected to the first end of the seventeenth resistor and the first end of the eighteenth resistor, the sixth end of the second dual operational amplifier chip is respectively connected to the second end of the fifteenth resistor and the second end of the sixteenth resistor, the eighth end of the second dual operational amplifier chip is respectively connected to the first end of the seventeenth capacitor, the first end of the sixteenth capacitor and the first end of the fourteenth resistor;

[0021] Correspondingly, the second end of the eighth resistor and the second end of the fourteenth resistor are both used to receive a third preset voltage, the first end of the eleventh resistor and the first end of the nineteenth resistor are both used to receive a fourth preset voltage, the third end of the second dual operational amplifier chip is used to receive a preset reference voltage, the second ends of the twelfth capacitor, the thirteenth capacitor, the first end of the fourteenth capacitor, the first end of the fifteenth capacitor, the second end of the sixteenth capacitor, the second end of the seventeenth capacitor, the first end of the eighteenth capacitor, the first end of the nineteenth capacitor and the second end of the eighteenth resistor are all grounded, and the first end of the thirteenth resistor is used to receive a target input signal.

[0022] Preferably, both the first dual operational amplifier chip and the second dual operational amplifier chip are chopper operational amplifier chips.

[0023] To solve the above technical problems, the present invention also provides a protection system for a constant current source circuit, including a direction switching device for a constant current source circuit as disclosed above.

[0024] It can be seen that in the direction switching device for a constant current source circuit provided by the present invention, a constant current source circuit, an inverter, and an analog switch are provided on a PCB. Among them, the analog switch can switch the positive and negative of the power supply voltage of the constant current source circuit through the inverter. Compared with the prior art, the direction switching device provided by the present invention achieves the purpose of switching the direction of the constant current source circuit by changing the power supply voltage of the constant current source circuit. In this direction switching device, only one analog switch is used to switch the direction of the constant current source circuit, which can significantly reduce the number of traces of the direction switching device of the constant current source circuit on the PCB, and enable the weak current signal output by the constant current source circuit not to pass through the vias on the PCB, thereby avoiding the leakage phenomenon generated by the direction switching device of the constant current source circuit on the PCB. Correspondingly, a protection system for a constant current source circuit provided by the present invention also has the above beneficial effects. Description of the Drawings

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to the provided drawings.

[0026] Figure 1 It is a structural diagram of a direction switching device for a constant current source circuit in the prior art;

[0027] Figure 2 It is a structural diagram of a direction switching device for a constant current source circuit provided by an embodiment of the present invention;

[0028] Figure 3 It is a schematic diagram of the principle when switching the direction of the constant current source circuit;

[0029] Figure 4 It is a structural diagram of an inverter provided by an embodiment of the present invention;

[0030] Figure 5 It is a structural diagram of a power supply chip provided by an embodiment of the present invention;

[0031] Figure 6 It is a structural diagram of an analog switch provided by an embodiment of the present invention;

[0032] Figure 7Structural diagram of another direction switching device for the constant current source circuit provided by the embodiment of the present invention;

[0033] Figure 8 Structural diagram of a constant current source circuit and a signal acquisition circuit provided by the embodiment of the present invention. Specific embodiments

[0034] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0035] Please refer to Figure 2 , Figure 2 Structural diagram of a direction switching device for a constant current source circuit provided by the embodiment of the present invention. The direction switching device includes: PCB10, on which a constant current source circuit 11, an inverter 12, and an analog switch 13 are provided. The analog switch 13 switches the positive and negative of the power supply voltage of the constant current source circuit 11 through the inverter 12.

[0036] In this embodiment, a direction switching device for a constant current source circuit is provided. By using this device to switch the direction of the constant current source circuit 11, the leakage phenomenon generated by the switching device of the constant current source circuit 11 on the PCB10 can be avoided.

[0037] In the direction switching device of the constant current source circuit, a constant current source circuit 11, an inverter 12, and an analog switch 13 are provided. Among them, the analog switch 13 can switch the positive and negative of the power supply voltage of the constant current source circuit 11 through the inverter 12.

[0038] Please refer to Figure 3 , Figure 3 Schematic diagram of the principle when switching the direction of the constant current source circuit. Assume that the output voltage of the power supply 14 is 2.5V. Combining Figure 2 and Figure 3 it can be known that when the first input terminal of the analog switch 13 is connected to the power supply 14 and the output terminal of the analog switch 13 is connected to the constant current source circuit 11, the power supply 14 can provide a positive 2.5V reference voltage to the constant current source circuit 11; when the second input terminal of the analog switch 13 is connected to the output terminal of the inverter 12, the input terminal of the inverter 12 is connected to the power supply 14, and the output terminal of the analog switch 13 is connected to the constant current source circuit 11, the power supply 14 can provide a negative 2.5V reference voltage to the constant current source circuit 11.

[0039] Obviously, in this setting method, by using the inverter 12 to switch the positive and negative of the power supply voltage of the constant current source circuit 11, the purpose of switching the direction of the constant current source circuit 11 can be achieved. Moreover, in this direction switching device, only one analog switch 13 is used to switch the direction of the constant current source circuit 11, which can significantly reduce the number of traces of the direction switching device of the constant current source circuit on the PCB, and enable the weak current signal output by the constant current source circuit 11 not to pass through the vias on the PCB10, thereby avoiding the leakage phenomenon generated by the switching device of the constant current source circuit 11 on the PCB10.

[0040] It should be noted that the device described in this application refers to a device or instrument that widely includes various components. Specifically, a direction switching device of a constant current source circuit described in this application refers to a circuit board including a PCB10, a constant current source circuit 11, an inverter 12, and an analog switch 13.

[0041] It can be seen that in the direction switching device of the constant current source circuit provided in this embodiment, a constant current source circuit, an inverter, and an analog switch are provided on the PCB. Among them, the analog switch can switch the positive and negative of the power supply voltage of the constant current source circuit through the inverter. Compared with the prior art, the direction switching device provided in this embodiment achieves the purpose of switching the direction of the constant current source circuit by changing the power supply voltage of the constant current source circuit. In this direction switching device, only one analog switch is used to switch the direction of the constant current source circuit, which can significantly reduce the number of traces of the direction switching device of the constant current source circuit on the PCB, and enable the weak current signal output by the constant current source circuit not to pass through the vias on the PCB, thereby avoiding the leakage phenomenon generated by the direction switching device of the constant current source circuit on the PCB.

[0042] Based on the above embodiments, this embodiment further describes and optimizes the technical solution. Please refer to Figure 4 , Figure 4 FIG. 13 is a structural diagram of an inverter provided in an embodiment of the present invention. As a preferred embodiment, the inverter 12 includes a single operational amplifier chip U1, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, and a sixth capacitor C6;

[0043] Among them, the first end of the first capacitor C1 is connected to the first end of the first resistor R1. The second end of the first resistor R1 is respectively connected to the first end of the third resistor R3 and the second end of the single operational amplifier chip U1. The fourth end of the single operational amplifier chip U1 is respectively connected to the first end of the second resistor R2, the first end of the second capacitor C2 and the first end of the third capacitor C3. The second end of the third resistor R3 is respectively connected to the first end of the sixth capacitor C6 and the sixth end of the single operational amplifier chip U1. The seventh end of the single operational amplifier chip U1 is respectively connected to the first end of the fourth capacitor C4, the first end of the fifth capacitor C5 and the first end of the fourth resistor R4;

[0044] Correspondingly, the first end of the first capacitor C1 is used to receive the first preset voltage output by the power supply chip. The first end of the sixth capacitor C6 is used to receive the second preset voltage. The second end of the fourth resistor R4 is used to receive the third preset voltage. The second end of the second resistor R2 is used to receive the fourth preset voltage. The second ends of the first capacitor C1, the second capacitor C2, the third capacitor C3, the fourth capacitor C4, the fifth capacitor C5 and the sixth capacitor C6 are all grounded.

[0045] In this embodiment, the inverter in the direction switching device is specifically described. That is, in practical applications, the single operational amplifier chip U1, the first resistor R1, the second resistor R2, the third resistor R3, the fourth resistor R4, the first capacitor C1, the second capacitor C2, the third capacitor C3, the fourth capacitor C4, the fifth capacitor C5 and the sixth capacitor C6 can be used to build the inverter 12, and the inverter 12 is used to switch the positive and negative of the supply voltage of the constant current source circuit 11. It should be noted that in this embodiment, the first preset voltage is +2.5V, the second preset voltage is -2.5V, the third preset voltage is +5V, and the fourth preset voltage is -5V.

[0046] In Figure 4 In the shown circuit, the second resistor R2, the second capacitor C2 and the third capacitor C3 form an RC circuit, which is used to filter the negative voltage of the single operational amplifier chip U1. The fourth capacitor C4, the fifth capacitor C5 and the fourth resistor R4 form an RC circuit, which is used to filter the positive voltage of the single operational amplifier chip U1.

[0047] Since the ADI series of chips have relatively high performance requirements in terms of EMI (Electro Magnetic Interference), size and efficiency, therefore, in practical applications, in order to ensure the stability and reliability of the inverter 11 during operation, the power supply chip can be set as an ADI power supply chip.

[0048] In addition, in order to further reduce the noise interference to the direction switching device of the constant current source circuit during operation, a power supply filter circuit for filtering the power supply voltage of the ADI power supply chip can also be provided in the direction switching device of the constant current source circuit.

[0049] It should be noted that in this application, the various ends on the single op amp chip, ADI power supply chip, ADI analog switch chip and dual op amp chip refer to the pins of the chip itself. In this application, in order to improve the readability of the application documents, the pins, input ends and output ends of various electronic components are collectively referred to as the various ends of the electronic components. This is hereby explained.

[0050] See also Figure 5 , Figure 5 This is a structural diagram of a power supply chip provided by an embodiment of the present invention. Figure 5 In FIG. 1 , U0 represents a power supply chip, and C01, C02, and C03 represent capacitors. Capacitors C01 and C02 can filter the power supply voltage of the power supply chip.

[0051] Based on the above embodiments, this embodiment further explains and optimizes the technical solution. Figure 6 , Figure 6 A structural diagram of an analog switch provided by an embodiment of the present invention. As a preferred implementation, the analog switch 13 includes: an ADI analog switch chip U2, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, a seventh capacitor C7, an eighth capacitor C8, a ninth capacitor C9, a tenth capacitor C10 and an eleventh capacitor C11;

[0052] Among them, the first end of the ADI analog switch chip U2 is respectively connected to the first end of the fifth resistor R5 and the first end of the seventh capacitor C7, the seventh end of the ADI analog switch chip U2 is respectively connected to the first end of the sixth resistor R6, the first end of the eighth capacitor C8 and the first end of the ninth capacitor C9, and the fourth end of the ADI analog switch chip U2 is respectively connected to the first end of the seventh resistor R7, the first end of the tenth capacitor C10 and the first end of the eleventh capacitor C11;

[0053] Correspondingly, the second ends of the fifth resistor R5, the seventh capacitor C7, the eighth capacitor C8, the ninth capacitor C9, the tenth capacitor C10, and the eleventh capacitor C11 are all grounded. The first end of the ADI analog switch chip U2 is used to receive a preset reference voltage, the second end of the ADI analog switch chip U2 is used to receive a first preset voltage, the eighth end of the ADI analog switch chip U2 is used to receive a second preset voltage, the second end of the seventh resistor R7 is used to receive a third preset voltage, the second end of the sixth resistor R6 is used to receive a fourth preset voltage, and the sixth end of the ADI analog switch chip U2 is used to receive a target switching signal CUR_CHANGE.

[0054] In this embodiment, the analog switch 13 in the constant current source circuit direction switching device is specifically described. The analog switch 13 provided in this embodiment is a two-way analog switch. The analog switch 13 switches the input channels of the ADI analog switch chip U2 through the target switching signal received at the sixth end of the ADI analog switch chip U2.

[0055] In Figure 6 Among them, the sixth resistor R6, the eighth capacitor C8, and the ninth capacitor C9 form a group of RC circuits, and the seventh resistor R7, the tenth capacitor C10, and the eleventh capacitor C11 form another group of RC circuits. Both groups of RC circuits are used to filter the supply voltage of the ADI analog switch chip U2.

[0056] Based on the above embodiments, this embodiment further describes and optimizes the technical solution. Please refer to Figure 7 , Figure 7 FIG. is a structural diagram of another constant current source circuit direction switching device provided by an embodiment of the present invention. As a preferred implementation manner, the above direction switching device further includes:

[0057] A signal acquisition circuit 15 connected to the constant current source circuit 11 for acquiring signals.

[0058] It can be understood that since the main application scenario of the constant current source circuit 11 is signal acquisition of high-precision instruments, therefore, in the constant current source circuit direction switching device provided in this embodiment, a signal acquisition circuit 15 for acquiring signals is also provided, so as to improve the universality of the constant current source circuit direction switching device provided in this application in practical applications.

[0059] Based on the above embodiments, this embodiment further describes and optimizes the technical solution. Please refer to Figure 8 , Figure 8The figure shows the structural diagrams of a constant current source circuit and a signal acquisition circuit provided by an embodiment of the present invention. As a preferred embodiment, the constant current source circuit 11 includes: a first dual operational amplifier chip U3, a second dual operational amplifier chip U4, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14, a fifteenth resistor R15, a sixteenth resistor R16, a seventeenth resistor R17, an eighteenth resistor R18, a nineteenth resistor R19, a twentieth resistor R20, a twelfth capacitor C12, a thirteenth capacitor C13, a fourteenth capacitor C14, a fifteenth capacitor C15, a sixteenth capacitor C16, a seventeenth capacitor C17, an eighteenth capacitor C18, a nineteenth capacitor C19, a twentieth capacitor C20, and a twenty-first capacitor C21;

[0060] Among them, the first terminal of the first dual operational amplifier chip U3 is connected to the first terminal of the tenth resistor R10 and the first terminal of the fifteenth resistor R15. The second terminal of the first dual operational amplifier chip U3 is connected to the second terminal of the tenth resistor R10. The third terminal of the first dual operational amplifier chip U3 is respectively connected to the first terminal of the twelfth resistor R12 and the first terminal of the thirteenth resistor R13. The fourth terminal of the first dual operational amplifier chip U3 is respectively connected to the second terminal of the fourteenth capacitor C14, the second terminal of the fifteenth capacitor C15, and the second terminal of the eleventh resistor R11. The fifth terminal of the first dual operational amplifier chip U3 is respectively connected to the second terminal of the twelfth resistor R12, the second terminal of the thirteenth resistor R13, and the first terminal of the twentieth capacitor C20. The sixth terminal of the first dual operational amplifier chip U3 is connected to the second terminal of the ninth resistor R9. The seventh terminal of the first dual operational amplifier chip U3 is respectively connected to the first terminal of the ninth resistor R9 and the second terminal of the seventeenth resistor R17. The eighth terminal of the first dual operational amplifier chip U3 is respectively connected to the first terminal of the eighth resistor R8, the first terminal of the twelfth capacitor C12, and the first terminal of the thirteenth capacitor C13. The first terminal of the second dual operational amplifier chip U4 is connected to the first terminal of the twentieth resistor R20 and the first terminal of the twentieth capacitor C20. The second terminal of the second dual operational amplifier chip U4 is respectively connected to the seventh terminal of the second dual operational amplifier chip U4, the first terminal of the sixteenth resistor R16, the second terminal of the twentieth capacitor C20, and the second terminal of the twenty-first capacitor C21. The first terminal of the twenty-first capacitor C21 is connected to the second terminal of the twentieth resistor R20. The fourth terminal of the second dual operational amplifier chip U4 is respectively connected to the second terminal of the eighteenth capacitor C18, the second terminal of the nineteenth capacitor C19, and the second terminal of the nineteenth resistor R19. The fifth terminal of the second dual operational amplifier chip U4 is respectively connected to the first terminal of the seventeenth resistor R17 and the first terminal of the eighteenth resistor R18. The sixth terminal of the second dual operational amplifier chip U4 is respectively connected to the second terminal of the fifteenth resistor R15 and the second terminal of the sixteenth resistor R16. The eighth terminal of the second dual operational amplifier chip U4 is respectively connected to the first terminal of the seventeenth capacitor C17, the first terminal of the sixteenth capacitor C16, and the first terminal of the fourteenth resistor R14;

[0061] Correspondingly, the second ends of the eighth resistor R8 and the fourteenth resistor R14 are both used to receive the third preset voltage, the first ends of the eleventh resistor R11 and the nineteenth resistor R19 are both used to receive the fourth preset voltage, the third end of the second dual operational amplifier chip U4 is used to receive the preset reference voltage, and the second ends of the twelfth capacitor C12, the thirteenth capacitor C13, the first end of the fourteenth capacitor C14, the first end of the fifteenth capacitor C15, the second end of the sixteenth capacitor C16, the second end of the seventeenth capacitor C17, the first end of the eighteenth capacitor C18, the first end of the nineteenth capacitor C19, and the second end of the eighteenth resistor R18 are all grounded, and the first end of the thirteenth resistor R13 is used to receive the target input signal INPUT.

[0062] In this embodiment, the constant current source circuit 11 in the constant current source circuit direction switching device is specifically described. In Figure 8 the shown constant current source circuit, two dual operational amplifier chips are used to build the constant current source circuit, so as to improve the power supply accuracy of the constant current source circuit.

[0063] In Figure 8 , the eighth resistor R8, the twelfth capacitor C12, and the thirteenth capacitor C13 form the first group of RC circuits, the eleventh resistor R11, the fourteenth capacitor C14, and the fifteenth capacitor C15 form the second group of RC circuits, and these two groups of RC circuits are both used to filter the power supply of the first dual operational amplifier chip U3; the fourteenth resistor R14, the sixteenth capacitor C16, and the seventeenth capacitor C17 form the third group of RC circuits, and the nineteenth resistor R19, the eighteenth capacitor C18, and the nineteenth capacitor C19 form the fourth group of RC circuits, and these two groups of RC circuits are both used to filter the second dual operational amplifier chip U4.

[0064] In addition, in practical applications, the first dual operational amplifier chip U3 and the second dual operational amplifier chip U4 can both be set as chopper operational amplifier chips. Because the chopper operational amplifier chip can not only maintain stable performance output under high gain, but also maintain the stability of the output signal under the condition of load change. Therefore, when the first dual operational amplifier chip U3 and the second dual operational amplifier chip U4 are both set as chopper operational amplifier chips, the stability and reliability of the constant current source circuit direction switching device during actual operation can be further improved.

[0065] As a preferred implementation manner, the signal acquisition circuit 15 includes: a standard resistor R0, a sampling resistor Rs, and an ADC for signal conversion of the signals collected by the standard resistor R0 and the sampling resistor Rs;

[0066] Among them, the second end of the standard resistor R0 is used to receive the target input signal. The first end of the standard resistor R0 is connected to the first end of the sampling resistor Rs, and the fourth end of the sampling resistor Rs is grounded.

[0067] In this embodiment, the signal acquisition circuit 15 is specifically described. That is, in practical applications, the standard resistor R0 and the sampling resistor Rs in Figure 8 can be used to acquire signals. Among them, the standard resistor R0 refers to a resistor whose resistance value does not change with temperature, and the sampling resistor Rs refers to a resistor whose resistance value can change with temperature.

[0068] In addition, through the technical solution provided in this embodiment, since the number of traces of the direction switching device on the PCB can be significantly reduced, and the complexity of the traces on the PCB can be reduced, therefore, through this direction switching device, the signal interference problem encountered by the signal acquisition circuit 15 in the prior art during signal acquisition due to the complex traces on the PCB can also be solved, and thus the stability of the signal acquisition circuit 15 during signal acquisition can be further improved.

[0069] It should be noted that in practical applications, during the operation of the circuit, the standard resistor R0 and the sampling resistor Rs provided on the PCB will generate thermoelectric potential or contact potential due to the increase in temperature. In this embodiment, during the positive and negative switching of the constant current source circuit 11, the ADC can eliminate the thermoelectric potential or contact potential generated on the standard resistor R0 and the sampling resistor Rs by collecting the output signals of the standard resistor R0 and the sampling resistor Rs, and thus the signal acquisition accuracy of the signal acquisition circuit 15 can be further improved.

[0070] Obviously, through the technical solution provided in this embodiment, the universality of the constant current source circuit direction switching device provided in this application in practical applications can be further improved.

[0071] Correspondingly, the embodiment of the present invention further provides a protection system for a constant current source circuit, including a direction switching device for a constant current source circuit as disclosed above.

[0072] The protection system for a constant current source circuit provided by the embodiment of the present invention has the beneficial effects of a direction switching device for a constant current source circuit as disclosed above.

[0073] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. For the same or similar parts among the embodiments, reference can be made to each other. Finally, it should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of another identical element in the process, method, article or device including the said element.

[0074] The above has introduced in detail a direction switching device for a constant current source circuit and a protection system for a constant current source circuit provided by the present invention. Specific examples are used in this text to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A direction switching device for a constant current source circuit, characterized in that, it includes: A PCB, on which a constant current source circuit, an inverter, and an analog switch are provided, and the analog switch switches the positive and negative of the power supply voltage of the constant current source circuit through the inverter.

2. The direction switching device for a constant current source circuit according to claim 1, characterized in that, the inverter includes a single operational amplifier chip, a first resistor, a second resistor, a third resistor, a fourth resistor, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, and a sixth capacitor; wherein, the first end of the first capacitor is connected to the first end of the first resistor, the second end of the first resistor is respectively connected to the first end of the third resistor and the second end of the single operational amplifier chip, the fourth end of the single operational amplifier chip is respectively connected to the first end of the second resistor, the first end of the second capacitor, and the first end of the third capacitor, the second end of the third resistor is respectively connected to the first end of the sixth capacitor and the sixth end of the single operational amplifier chip, and the seventh end of the single operational amplifier chip is respectively connected to the first end of the fourth capacitor, the first end of the fifth capacitor, and the first end of the fourth resistor; Correspondingly, the first end of the first capacitor is used to receive a first preset voltage output by the power supply chip, the first end of the sixth capacitor is used to receive a second preset voltage, the second end of the fourth resistor is used to receive a third preset voltage, the second end of the second resistor is used to receive a fourth preset voltage, and the second ends of the first capacitor, the second capacitor, the third capacitor, the fourth capacitor, the fifth capacitor, and the sixth capacitor are all grounded.

3. The direction switching device for a constant current source circuit according to claim 2, characterized in that, the power supply chip is specifically an ADI power supply chip.

4. The direction switching device for a constant current source circuit according to claim 3, characterized in that, it further includes: A power supply filtering circuit for filtering the power supply voltage of the ADI power supply chip.

5. The direction switching device for a constant current source circuit according to claim 1, characterized in that, the analog switch includes: an ADI analog switch chip, a fifth resistor, a sixth resistor, a seventh resistor, a seventh capacitor, an eighth capacitor, a ninth capacitor, a tenth capacitor, and an eleventh capacitor; wherein, the first end of the ADI analog switch chip is respectively connected to the first end of the fifth resistor and the first end of the seventh capacitor, the seventh end of the ADI analog switch chip is respectively connected to the first end of the sixth resistor, the first end of the eighth capacitor, and the first end of the ninth capacitor, and the fourth end of the ADI analog switch chip is respectively connected to the first end of the seventh resistor, the first end of the tenth capacitor, and the first end of the eleventh capacitor; Correspondingly, the second ends of the fifth resistor, the seventh capacitor, the eighth capacitor, the ninth capacitor, the tenth capacitor, and the eleventh capacitor are all grounded. The first end of the ADI analog switch chip is used to receive a preset reference voltage, the second end of the ADI analog switch chip is used to receive a first preset voltage, the eighth end of the ADI analog switch chip is used to receive a second preset voltage, the second end of the seventh resistor is used to receive a third preset voltage, the second end of the sixth resistor is used to receive a fourth preset voltage, and the sixth end of the ADI analog switch chip is used to receive a target switching signal.

6. The direction switching device of a constant current source circuit according to claim 1, characterized in that, further comprising: a signal acquisition circuit connected to the constant current source circuit for acquiring signals.

7. The direction switching device of a constant current source circuit according to claim 6, characterized in that, the signal acquisition circuit includes: a standard resistor, a sampling resistor, and an ADC for signal conversion of the signals acquired by the standard resistor and the sampling resistor; wherein, the second end of the standard resistor is used to receive a target input signal, the first end of the standard resistor is connected to the first end of the sampling resistor, and the fourth end of the sampling resistor is grounded.

8. The direction switching device of a constant current source circuit according to any one of claims 1 to 7, characterized in that, the constant current source circuit includes: a first dual operational amplifier chip, a second dual operational amplifier chip, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, an eighteenth resistor, a nineteenth resistor, a twentieth resistor, a twelfth capacitor, a thirteenth capacitor, a fourteenth capacitor, a fifteenth capacitor, a sixteenth capacitor, a seventeenth capacitor, an eighteenth capacitor, a nineteenth capacitor, a twentieth capacitor, and a twenty-first capacitor; Among them, the first end of the first dual operational amplifier chip is connected to the first end of the tenth resistor and the first end of the fifteenth resistor. The second end of the first dual operational amplifier chip is connected to the second end of the tenth resistor. The third end of the first dual operational amplifier chip is respectively connected to the first end of the twelfth resistor and the first end of the thirteenth resistor. The fourth end of the first dual operational amplifier chip is respectively connected to the second end of the fourteenth capacitor, the second end of the fifteenth capacitor and the second end of the eleventh resistor. The fifth end of the first dual operational amplifier chip is respectively connected to the second end of the twelfth resistor, the second end of the thirteenth resistor and the first end of the twentieth capacitor. The sixth end of the first dual operational amplifier chip is connected to the second end of the ninth resistor. The seventh end of the first dual operational amplifier chip is respectively connected to the first end of the ninth resistor and the second end of the seventeenth resistor. The eighth end of the first dual operational amplifier chip is respectively connected to the first end of the eighth resistor, the first end of the twelfth capacitor and the first end of the thirteenth capacitor. The first end of the second dual operational amplifier chip is connected to the first end of the twentieth resistor and the first end of the twentieth capacitor. The second end of the second dual operational amplifier chip is respectively connected to the seventh end of the second dual operational amplifier chip, the first end of the sixteenth resistor, the second end of the twentieth capacitor and the second end of the twenty-first capacitor. The first end of the twenty-first capacitor is connected to the second end of the twentieth resistor. The fourth end of the second dual operational amplifier chip is respectively connected to the second end of the eighteenth capacitor, the second end of the nineteenth capacitor and the second end of the nineteenth resistor. The fifth end of the second dual operational amplifier chip is respectively connected to the first end of the seventeenth resistor and the first end of the eighteenth resistor. The sixth end of the second dual operational amplifier chip is respectively connected to the second end of the fifteenth resistor and the second end of the sixteenth resistor. The eighth end of the second dual operational amplifier chip is respectively connected to the first end of the seventeenth capacitor, the first end of the sixteenth capacitor and the first end of the fourteenth resistor; Correspondingly, the second end of the eighth resistor and the second end of the fourteenth resistor are both used to receive a third preset voltage. The first end of the eleventh resistor and the first end of the nineteenth resistor are both used to receive a fourth preset voltage. The third end of the second dual operational amplifier chip is used to receive a preset reference voltage. The second ends of the twelfth capacitor, the thirteenth capacitor, the first end of the fourteenth capacitor, the first end of the fifteenth capacitor, the second end of the sixteenth capacitor, the second end of the seventeenth capacitor, the first end of the eighteenth capacitor, the first end of the nineteenth capacitor and the second end of the eighteenth resistor are all grounded. The first end of the thirteenth resistor is used to receive a target input signal.

9. A direction switching device for a constant current source circuit according to claim 8, Characterized in that, Both the first dual operational amplifier chip and the second dual operational amplifier chip are chopper operational amplifier chips.

10. A protection system for a constant current source circuit, Characterized in that, A direction switching device including a constant current source circuit according to any one of claims 1 to 9.

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