Circuit for controlling voltage scaling ratio of operational amplifier by using relay

Abstract

The utility model relates to the related field of circuit design, in particular to a circuit for controlling the voltage scaling ratio of an operational amplifier by using a relay. According to the utility model, through the OP07CP operational amplifier, the offset voltage drift voltage of the OP07CP operational amplifier is very small by utilizing the low offset voltage characteristic of the OP07CP operational amplifier, errors caused by offset voltage introduction are avoided, the precision is high, the noise is low, the common-mode rejection ratio is high, the power supply voltage range is wide, small signals can be amplified and processed more accurately, and the power supply voltage range is wide. Moreover, the voltage scaling ratio of the circuit can be dynamically adjusted, the design allows the circuit to adapt to various input signal ranges, and the universality and flexibility of the system are improved.

Description

Technical Field

[0001] This utility model relates to the field of circuit design, and in particular to a circuit that uses a relay to control the voltage scaling ratio of an operational amplifier. Background Technology

[0002] Accurate voltage data acquisition and processing are crucial in numerous fields, including industrial production, environmental monitoring, and smart homes. With the rapid development of solar cell technology, perovskite cells have emerged as a new type of photovoltaic cell. However, existing perovskite cell testers have relatively narrow testing ranges, and current voltage acquisition equipment typically only handles a limited voltage range, failing to adapt to the wide output voltage range of perovskite cells and other new photovoltaic cells. This results in incomplete test results. While acquisition equipment can sense voltage changes and generate corresponding electrical signals, it suffers from numerous limitations in practical applications. Furthermore, traditional voltage acquisition equipment is susceptible to external electromagnetic interference during signal transmission, leading to fluctuations and errors in the acquired voltage data. In scenarios requiring precise voltage data for decision-making, such as high-precision industrial production process control and scientific research experiments with stringent voltage stability requirements, the accuracy and stability of current voltage acquisition technologies are far from sufficient. The acquired results deviate significantly from the actual voltage signal, severely limiting further development and application in related fields. Summary of the Invention

[0003] Therefore, in order to overcome the above-mentioned shortcomings, this utility model provides a circuit that uses a relay to control the voltage scaling ratio of an operational amplifier, thereby solving the above-mentioned technical problems.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: a circuit for controlling the voltage scaling ratio of an operational amplifier using a relay, comprising a microcontroller, a relay, a control circuit, and an operational amplifier module. The relay is electrically connected to the microcontroller, the control circuit is connected to the relay, and the operational amplifier is connected to the control circuit. The operational amplifier is used to receive high voltage and low voltage signals output by the control circuit, and to amplify the high voltage and low voltage input signals. The processed signals are then fed back to the microcontroller.

[0005] The operational amplifier module includes at least three OP07CP operational amplifiers and a relay feedback resistor module. The three operational amplifiers are OP07CP operational amplifier A1, OP07CP operational amplifier A2, and OP07CP operational amplifier A3. The non-inverting input terminals of OP07CP operational amplifier A1 and OP07CP operational amplifier A2 are connected to the positive and negative terminals of the input signal, respectively. OP07CP operational amplifier A3 receives the output signals of OP07CP operational amplifier A1 and OP07CP operational amplifier A2 through a resistor network and performs final amplification and output. The relay feedback resistor module includes multiple resistors of different resistance values ​​connected in parallel, and each resistor is connected to the feedback loop through a relay contact connected in series with it.

[0006] The relay is used to switch different feedback resistors to dynamically adjust the voltage scaling ratio of the circuit, allowing the circuit to adapt to a variety of input signal ranges.

[0007] Preferably, the OP07CP operational amplifier and relay are both powered by independent 12V batteries. After the positive power supply terminal of the operational amplifier is connected to the control circuit, it is connected to the positive terminal of the power supply. The negative power supply line is connected to the ground terminal of the system to ensure electrical safety. On the other hand, it also provides a current loop for signal transmission and power supply between the relay, operational amplifier and microcontroller. It is connected to the ground pin of the microcontroller to form a complete signal and power transmission link.

[0008] Preferably, the battery has a voltage regulator diode between the OP07CP operational amplifier and the relay.

[0009] Preferably, when the circuit is not in operation, the power supply to the relay can be cut off by the microcontroller, so that the circuit enters a sleep mode and reduces power consumption.

[0010] Preferably, the inverting input terminal of the OP07CP operational amplifier A1 is connected to its output terminal through a resistor R1, and the inverting input terminal of the OP07CP operational amplifier A2 is connected to its output terminal through a resistor R3.

[0011] Preferably, the resistors R1 and R3 are connected by a 2KΩ resistor R2.

[0012] Preferably, the output terminal of the OP07CP operational amplifier A2 is connected to the non-inverting input terminal of the OP07CP operational amplifier A3 through a resistor R5. The non-inverting input terminal of the OP07CP operational amplifier A3 is also connected to an adjustable resistor R7 in parallel with the resistor R5, and the other end of the adjustable resistor R7 is grounded.

[0013] Preferably, the operational amplifier has 8 pins to achieve a three-level architecture functional allocation.

[0014] The beneficial effects of this utility model are:

[0015] This invention utilizes the OP07CP operational amplifier, which features low offset voltage characteristics to minimize offset voltage drift, thus avoiding errors introduced by offset voltage. Furthermore, it offers high precision, low noise, high common-mode rejection ratio, and a wide power supply voltage range, enabling more accurate amplification and processing of small signals. The amplifier also allows for dynamic adjustment of the circuit's voltage scaling ratio, allowing the circuit to adapt to various input signal ranges and improving the system's versatility and flexibility. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall circuit flow structure of the circuit design of this utility model;

[0017] Figure 2 This is a schematic diagram of the internal circuit structure of the operational amplifier module of this utility model. Detailed Implementation

[0018] To further explain the technical solution of this utility model, a detailed description is provided below through specific embodiments.

[0019] like Figure 1 and Figure 2 As shown, this utility model provides a circuit for controlling the voltage scaling ratio of an operational amplifier using a relay, including a microcontroller, a relay, a control circuit, and an operational amplifier module. The microcontroller is used to send commands.

[0020] The relay is electrically connected to the microcontroller and is used to receive instructions from the microcontroller;

[0021] The control circuit connects to the relay and is used to output high voltage and low voltage input terminals.

[0022] The operational amplifier module is connected to the control circuit. It is used to receive the high voltage and low voltage signals output by the control circuit, amplify the high voltage and low voltage input signals, and feed the processed signals back to the microcontroller.

[0023] The operational amplifier module includes:

[0024] At least three OP07CP operational amplifiers are provided, namely OP07CP operational amplifier A1, OP07CP operational amplifier A2, and OP07CP operational amplifier A3. The non-inverting input terminals of OP07CP operational amplifier A1 and OP07CP operational amplifier A2 are connected to the positive and negative terminals of the input signal, respectively. OP07CP operational amplifier A3 receives the output signals of OP07CP operational amplifier A1 and OP07CP operational amplifier A2 through a resistor network and performs final amplification and output.

[0025] The OP07CP operational amplifier utilizes its low offset voltage, low offset voltage drift, high common-mode rejection ratio, and wide power supply voltage range to perform high-precision amplification and noise suppression of small input signals, enabling more accurate amplification and processing of small signals.

[0026] The relay feedback resistor module includes a 100KΩ resistor R6, a 50KΩ resistor R61, and a 200KΩ resistor R62 connected in parallel. Resistors R61 and R62 are connected to the feedback loop through relay contacts K1 and K2 connected in series with them, respectively.

[0027] The relay is used to switch different feedback resistors to dynamically adjust the voltage scaling ratio of the circuit, allowing the circuit to adapt to a variety of input signal ranges and improving the versatility and flexibility of the system.

[0028] The input signal is simultaneously connected to the non-inverting input terminals of A1 and A2. A1 and A2 form a differential input preamplifier circuit. A1 outputs a signal to point X, and A2 outputs a signal to point Y. In this stage, the input signal is initially amplified and common-mode interference is suppressed. The signal at point X is transmitted to the inverting input terminal of A3 via R4, and the signal at point Y is transmitted to the non-inverting input terminal of A3 via R5. A3 performs differential amplification on the potential difference between points X and Y to increase the signal amplitude. A3 determines the amplification factor through the feedback loop formed by R6, R61, and R62, and outputs the processed signal as VO.

[0029] The OP07CP operational amplifier has 8 pins: pin 1 and pin 5 are zero bias terminals, pin 2 is the inverting input terminal, pin 3 is the non-inverting input terminal, pin 4 is the negative power supply terminal, pin 6 is the output terminal, pin 7 is the positive power supply terminal, and pin 8 is a no-connect pin.

[0030] The OP07CP operational amplifier implements a three-level architecture with functional allocation:

[0031] Operational amplifier A1 is a differential input stage used to receive the non-inverting input signal;

[0032] Operational amplifier A2 is a differential input stage used to receive the inverting input signal;

[0033] Operational amplifier A3 is a differential amplifier output stage that combines the signals from the first two stages and performs the final amplification.

[0034] This three-level architecture can effectively suppress common-mode interference, improve input impedance, and achieve dynamic gain adjustment by switching the feedback resistor through relays.

[0035] In this embodiment, the relay is powered by an independent 12V battery (not shown in the figure), and the OP07CP operational amplifier uses a ±12V power input. After the positive power supply terminal of the OP07CP operational amplifier is connected to the control circuit, it is connected to the positive terminal of the power supply. The negative power supply line is connected to the ground terminal of the system to ensure electrical safety. On the other hand, it also provides a current loop for signal transmission and power supply between the relay, operational amplifier and microcontroller, and is connected to the ground pin of the microcontroller to form a complete signal and power transmission link.

[0036] The battery has a Zener diode between the OP07CP operational amplifier and the relay to improve and increase the stability of the input power supply and reduce damage to the circuit.

[0037] In this embodiment, when the circuit is not in operation, the microcontroller can cut off the power supply to the relay, causing the circuit to enter a sleep mode and reduce power consumption. The relay is powered by an independent power supply. The microcontroller controls the power supply to the relay by controlling the electronic switch (not shown in the figure) in the power supply circuit. When the system is not in operation, the microcontroller sends a control signal to disconnect the electronic switch, cut off the power supply to the relay, and stop the relay from working, thereby reducing unnecessary power consumption and realizing a sleep mechanism to reduce power consumption.

[0038] In this embodiment, the inverting input terminal of the OP07CP operational amplifier A1 is connected to its output terminal through a 100KΩ resistor R1, and the inverting input terminal of the OP07CP operational amplifier A2 is connected to its output terminal through a 100KΩ resistor R3. By setting R1, A1 is configured as a unity-gain buffer to avoid generating a load effect on the signal source. R1 and R3 respectively enable A1 and A2 to form a negative feedback mechanism, constituting a voltage follower circuit structure, providing high input impedance for A1 and A2 respectively, reducing the impact on the input signal source, and ensuring stable signal transmission.

[0039] Resistors R1 and R3 are connected by a 2KΩ resistor R2. R2, together with R1 and R3, improves the symmetry and balance of the differential input circuit, helps to improve the circuit's ability to suppress common-mode signals, reduces the impact of common-mode interference on the circuit, and improves the signal-to-noise ratio.

[0040] In this embodiment, the output terminal of the OP07CP operational amplifier A2 is connected to the non-inverting input terminal of the OP07CP operational amplifier A3 through a resistor R5. The non-inverting input terminal of the OP07CP operational amplifier A3 is also connected to an adjustable resistor R7 in parallel with the resistor R5. The other end of the adjustable resistor R7 is grounded. By adjusting the resistance value of R7, the potential of the non-inverting input terminal of A3 can be changed, thereby adjusting the amplification characteristics of the circuit.

[0041] Specifically, the microcontroller issues commands based on a preset program or external input signals. These commands are then transmitted to relays, which act as switches, connecting or disconnecting the circuit according to the commands. The relays transmit signals to the control circuit, which processes and adjusts the signals. The control circuit outputs both high and low voltage signals as needed. These signals are then transmitted to the operational amplifier module. The operational amplifier module receives the high and low voltage signals from the control circuit and amplifies them using its internal circuitry. The high voltage signal is amplified by a non-inverting amplifier to output a high voltage, while the low voltage signal is amplified by an inverting amplifier to output a low voltage. The amplified high and low voltage signals are then fed back to the microcontroller via feedback paths. This feedback mechanism enables the system to monitor the output status in real time and adjust the microcontroller's commands based on the feedback information, thereby achieving closed-loop control and ensuring stable system operation.

[0042] When the states of relay contacts K1 and K2 change, the corresponding feedback resistors R61 and R62 are connected to or disconnected from the feedback loop. For example, when K1 is closed and K2 is open, R61 is connected to the feedback loop, forming a parallel or other combination relationship with R6, thereby changing the total resistance of the feedback loop. The change in the resistance of the feedback resistor directly leads to a change in the circuit gain, thereby adjusting the voltage scaling ratio. Conversely, when K1 is open and K2 is closed, the circuit gain also changes. This design allows the circuit to adapt to a variety of input signal ranges, improving the versatility and flexibility of the system.

[0043] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A circuit that uses a relay to control the voltage scaling ratio of an operational amplifier, characterized in that, include: The microcontroller is used to send commands; A relay is electrically connected to a microcontroller and is used to receive instructions from the microcontroller. The control circuit connects to the relay and is used to output high voltage and low voltage input terminals. The operational amplifier module is connected to the control circuit. It is used to receive the high voltage and low voltage signals output by the control circuit, amplify the high voltage and low voltage input signals, and feed the processed signals back to the microcontroller. The operational amplifier module includes: At least three OP07CP operational amplifiers are provided, namely OP07CP operational amplifier A1, OP07CP operational amplifier A2, and OP07CP operational amplifier A3. The non-inverting input terminals of OP07CP operational amplifier A1 and OP07CP operational amplifier A2 are connected to the positive and negative terminals of the input signal, respectively. OP07CP operational amplifier A3 receives the output signals of OP07CP operational amplifier A1 and OP07CP operational amplifier A2 through a resistor network and performs final amplification and output. The relay feedback resistor module includes multiple resistors of different resistance values ​​connected in parallel, and each resistor is connected to the feedback loop through a relay contact connected in series with it. The relay is used to switch different feedback resistors to dynamically adjust the voltage scaling ratio of the circuit, allowing the circuit to adapt to a variety of input signal ranges.

2. The circuit for controlling the voltage scaling ratio of an operational amplifier using a relay according to claim 1, characterized in that: The OP07CP operational amplifier and relay are both powered by independent 12V batteries. After the positive power supply terminal of the operational amplifier is connected to the control circuit, it is connected to the positive terminal of the power supply. The negative power supply line is connected to the ground terminal of the system to ensure electrical safety. On the other hand, it also provides a current loop for signal transmission and power supply between the relay, operational amplifier and microcontroller. It is connected to the ground pin of the microcontroller to form a complete signal and power transmission link.

3. The circuit for controlling the voltage scaling ratio of an operational amplifier using a relay according to claim 2, characterized in that: The battery has a voltage regulator diode installed between the OP07CP operational amplifier and the relay.

4. The circuit for controlling the voltage scaling ratio of an operational amplifier using a relay according to claim 2, characterized in that: When the circuit is not in operation, the microcontroller can cut off the power supply to the relay, putting the circuit into sleep mode and reducing power consumption.

5. The circuit for controlling the voltage scaling ratio of an operational amplifier using a relay according to claim 1, characterized in that: The inverting input terminal of the OP07CP operational amplifier A1 is connected to its output terminal through resistor R1, and the inverting input terminal of the OP07CP operational amplifier A2 is connected to its output terminal through resistor R3.

6. The circuit for controlling the voltage scaling ratio of an operational amplifier using a relay according to claim 5, characterized in that: The resistors R1 and R3 are connected by a resistor R2.

7. The circuit for controlling the voltage scaling ratio of an operational amplifier using a relay according to claim 1, characterized in that: The output terminal of the OP07CP operational amplifier A2 is connected to the non-inverting input terminal of the OP07CP operational amplifier A3 through a resistor R5. The non-inverting input terminal of the OP07CP operational amplifier A3 is also connected to an adjustable resistor R7 in parallel with the resistor R5, and the other end of the adjustable resistor R7 is grounded.

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