Three-stage amplifying circuit for acquiring temperature signal of switch
By cascading amplification of the switch's temperature signal using a three-stage amplifier circuit, the problem of inaccurate temperature signal acquisition by the switch is solved, and weak signals are effectively amplified, thereby improving the stability and operating speed of the switch.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- UNIPOE IOT TECH CO LTD
- Filing Date
- 2025-05-21
- Publication Date
- 2026-04-21
AI Technical Summary
In existing technologies, temperature signal acquisition by switches is not accurate enough, especially the amplification effect on weak signals is insufficient, which affects the stability and operating speed of the switches.
A three-stage amplifier circuit is adopted, including a signal input terminal, a signal output terminal, a power supply, first to third transistors, first to fourth resistors, a first capacitor, and a second capacitor. Through the cascade amplification of the first to third transistors, the temperature signal of the switch is accurately acquired.
It enables accurate acquisition of temperature signals from the switch, meets the amplification requirements of weak signals, and improves the stability and operating speed of the switch.
Smart Images
Figure CN224154188U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of switches, specifically to a three-stage amplifier circuit for acquiring temperature signals from a switch. Background Technology
[0002] As a crucial relay station in a local area network (LAN), a switch provides reliable protection for the LAN. During prolonged use, components such as the circuit boards within a switch generate significant heat. As the switch temperature rises, its operating speed decreases, affecting its stability. Therefore, it is necessary to monitor the internal temperature of the switch in real time.
[0003] Therefore, temperature sensors are typically installed to continuously monitor the temperature of critical components of the switch. Currently, the acquisition of temperature signals from switches is usually quite simple, and when the temperature signal is weak, it is often impossible to acquire it accurately. Utility Model Content
[0004] This application provides a three-stage amplifier circuit for acquiring temperature signals from a switch, which can achieve accurate acquisition of temperature signals from the switch.
[0005] This application provides a three-stage amplifier circuit for acquiring temperature signals from a switch, comprising: a signal input terminal, a signal output terminal, a power supply, first to third transistors, first to fourth resistors, a first capacitor, and a second capacitor;
[0006] The base of the first transistor is connected to the signal input terminal through a first capacitor, the emitter is grounded, and the collector is connected to the base of the second transistor.
[0007] A first resistor is connected between the base of the second transistor and the power supply, and the collector of the second transistor is connected to the base of the third transistor, while the emitter is grounded.
[0008] A second resistor is connected between the base of the third transistor and the power supply, the collector of the third transistor is connected to the power supply, and the emitter is connected to the signal output terminal through a second capacitor.
[0009] One end of the third resistor is connected to the emitter of the third transistor, and the other end is grounded;
[0010] One end of the fourth resistor is connected between the second capacitor and the signal output terminal, and the other end is grounded.
[0011] In some embodiments, a fifth resistor is connected between the first capacitor and the signal input terminal.
[0012] In some embodiments, the emitter of the second transistor is connected to a sixth resistor, the other end of the sixth resistor is connected to a seventh resistor, and the other end of the seventh resistor is grounded.
[0013] The base of the first transistor is connected between the sixth and seventh resistors.
[0014] In some embodiments, the system further includes an eighth resistor and a third capacitor. One end of the eighth resistor is connected to the base of the first transistor, and the other end is connected between the sixth and seventh resistors. The third capacitor is a polarized capacitor, with its positive terminal connected between the sixth and seventh resistors and its negative terminal grounded.
[0015] In some embodiments, a ninth resistor and a tenth resistor are also included, the tenth resistor being connected between the emitter of the first transistor and ground, one end of the ninth resistor being connected between the fifth resistor and the first capacitor, and the other end being grounded.
[0016] In some embodiments, an eleventh resistor and a fourth capacitor are connected in series between the emitter of the third transistor and the emitter of the first transistor.
[0017] In some embodiments, the first transistor, the second transistor, and the third transistor are NPN transistors.
[0018] The technical solution of this application has at least the following advantages:
[0019] 1. By configuring the first to third transistors, when the switch temperature signal is input through the signal input terminal, it first undergoes a first-stage amplification through the first transistor, and then enters the second transistor from the collector of the first transistor, causing the second transistor to perform a second-stage amplification. After that, the amplified switch temperature signal enters the third transistor through the collector of the second transistor. The third transistor, acting as an emitter follower, can reduce the output impedance of the switch temperature signal. Finally, the amplified switch temperature signal is output through the signal output terminal, realizing accurate acquisition of the switch temperature signal and meeting the amplification requirements of weak signals. Attached Figure Description
[0020] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0021] Figure 1 This is a circuit diagram of a three-stage amplifier circuit for acquiring temperature signals from a switch, provided in an exemplary embodiment of this application. Detailed Implementation
[0022] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0023] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0024] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components; and they can refer to a wireless connection or a wired connection. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0025] Furthermore, the technical features involved in the different embodiments of this application described below can be combined with each other as long as they do not conflict with each other.
[0026] This application provides a three-stage amplifier circuit for temperature signal acquisition from a switch, referring to... Figure 1 The circuit includes a signal input terminal Vin, a signal output terminal Vout, a power supply, a first transistor Q1, a second transistor Q2, a third transistor Q3, first to fourth resistors R1 to R4, a first capacitor C1, and a second capacitor C2. The base of the first transistor Q1 is connected to the signal input terminal Vin via the first capacitor C1. When the switch temperature signal is input through Vin, the first capacitor C1 acts as an input coupling capacitor, isolating the DC component and allowing only the AC signal to enter the base of the first transistor Q1. The emitter of the first transistor Q1 is grounded, and its collector is connected to the base of the second transistor Q2, so that the amplified switch temperature signal is input to the second transistor Q2 through its collector.
[0027] A first resistor R1 is connected between the base of the second transistor Q2 and the positive terminal VCC of the power supply. R1 acts as a voltage divider resistor for the base of the second transistor Q2. The collector of the second transistor Q2 is connected to the base of the third transistor Q3, and its emitter is grounded. The switch temperature signal, amplified by the second transistor Q2, enters the base of the third transistor Q3 through the collector of the second transistor Q2.
[0028] A second resistor R2 is connected between the base of the third transistor Q3 and the positive terminal VCC of the power supply. The second resistor R2 serves as the base voltage divider resistor for the third transistor Q3. The collector of the third transistor Q3 is connected to the positive terminal VCC of the power supply, and the emitter is connected to the signal output terminal Vout through the second capacitor C2.
[0029] One end of the third resistor R3 is connected to the emitter of the third transistor Q3, and the other end is grounded. One end of the fourth resistor R4 is connected between the second capacitor C2 and the signal output terminal Vout, and the other end is grounded. The third resistor R3, acting as the emitter resistor of the third transistor Q3, provides DC negative feedback, stabilizing the quiescent operating point of Q3. The fourth resistor R4 serves as the load resistor for the signal output terminal Vout.
[0030] Furthermore, a fifth resistor R5 is connected between the first capacitor C1 and the signal input terminal Vin. The fifth resistor R5 acts as a series resistor at the input terminal, and together with the second capacitor C2, they form a high-pass filter to filter out low-frequency interference.
[0031] Furthermore, the emitter of the second transistor Q2 is connected to a sixth resistor R6, the other end of which is connected to a seventh resistor R7, the other end of which is grounded. The base of the first transistor Q1 is connected between the sixth resistor R6 and the seventh resistor R7. The sixth resistor R6 and the seventh resistor R7 together form a base voltage divider bias for the first transistor Q1.
[0032] Furthermore, the three-stage amplification circuit for acquiring the switch temperature signal also includes an eighth resistor R8 and a third capacitor C3. One end of the eighth resistor R8 is connected to the base of the first transistor Q1, and the other end is connected between the sixth resistor R6 and the seventh resistor R7. The third capacitor C3 is a polarized capacitor, with its positive terminal connected between the sixth resistor R6 and the seventh resistor R7, and its negative terminal grounded. The eighth resistor R8 and the third capacitor C3 form an RC filter circuit to filter out high-frequency noise in the switch temperature signal.
[0033] Furthermore, the three-stage amplifier circuit for acquiring the temperature signal from the switch also includes a ninth resistor R9 and a tenth resistor R10. The tenth resistor R10 is connected between the emitter of the first transistor Q1 and ground. One end of the ninth resistor R9 is connected between the fifth resistor R5 and the first capacitor C1, and the other end is grounded. The ninth resistor R9 and the tenth resistor R10 serve as negative feedback resistors for the emitter of the first transistor Q1, which can stabilize the DC operating point and improve linearity.
[0034] Furthermore, an eleventh resistor R11 and a fourth capacitor C4 are connected in series between the emitter of the third transistor Q3 and the emitter of the first transistor Q1. The eleventh resistor R11 is the emitter resistor of the third transistor Q3, which limits the output stage current and provides local negative feedback. The fourth capacitor C4 prevents DC components from affecting the load and transmits only AC signals. At the same time, since the emitter of the third transistor Q3 is also connected to the third resistor R3, the third resistor R3 also serves as the emitter resistor of the second transistor Q2, thereby providing DC negative feedback for the second transistor Q2 and stabilizing the quiescent operating point of the second transistor Q2.
[0035] Furthermore, the first transistor Q1, the second transistor Q2, and the third transistor Q3 are NPN type transistors. For example, their model number could be 2N2222.
[0036] This application provides a three-stage amplification circuit for acquiring temperature signals from a switch. Through the arrangement of the first to third transistors, when the switch temperature signal is input through the signal input terminal, it first undergoes a first-stage amplification by the first transistor, and then enters the second transistor from the collector of the first transistor for a second-stage amplification. Afterward, the amplified switch temperature signal enters the third transistor from the collector of the second transistor. The third transistor, acting as an emitter follower, reduces the output impedance of the switch temperature signal. Finally, the amplified switch temperature signal is output through the signal output terminal, achieving accurate acquisition of the switch temperature signal and meeting the amplification requirements of weak signals.
[0037] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this application.
Claims
1. A three-stage amplification circuit for switch temperature signal acquisition, characterized in that, include: Signal input terminal, signal output terminal, power supply, first to third transistors, first to fourth resistors, first capacitor and second capacitor; The base of the first transistor is connected to the signal input terminal through a first capacitor, the emitter is grounded, and the collector is connected to the base of the second transistor. A first resistor is connected between the base of the second transistor and the power supply, and the collector of the second transistor is connected to the base of the third transistor, while the emitter is grounded. A second resistor is connected between the base of the third transistor and the power supply, the collector of the third transistor is connected to the power supply, and the emitter is connected to the signal output terminal through a second capacitor. One end of the third resistor is connected to the emitter of the third transistor, and the other end is grounded; One end of the fourth resistor is connected between the second capacitor and the signal output terminal, and the other end is grounded.
2. The three-stage amplification circuit for switch temperature signal acquisition according to claim 1, characterized in that, A fifth resistor is connected between the first capacitor and the signal input terminal.
3. The three-stage amplification circuit for switch temperature signal acquisition according to claim 2, characterized in that, The emitter of the second transistor is connected to a sixth resistor, the other end of the sixth resistor is connected to a seventh resistor, and the other end of the seventh resistor is grounded. The base of the first transistor is connected between the sixth and seventh resistors.
4. The three-stage amplification circuit for switch temperature signal acquisition according to claim 3, characterized in that, It also includes an eighth resistor and a third capacitor. One end of the eighth resistor is connected to the base of the first transistor, and the other end is connected between the sixth and seventh resistors. The third capacitor is a polarized capacitor, with its positive terminal connected between the sixth and seventh resistors and its negative terminal grounded.
5. The three-stage amplification circuit for switch temperature signal acquisition of claim 2, wherein, It also includes a ninth resistor and a tenth resistor. The tenth resistor is connected between the emitter of the first transistor and the ground line. One end of the ninth resistor is connected between the fifth resistor and the first capacitor, and the other end is grounded.
6. The three-stage amplification circuit for switch temperature signal acquisition of claim 1, wherein, An eleventh resistor and a fourth capacitor are connected in series between the emitter of the third transistor and the emitter of the first transistor.
7. The three-stage amplification circuit for switch temperature signal acquisition of claim 1, wherein, The first transistor, the second transistor, and the third transistor are NPN type transistors.