A continuously tunable analog phase shifter with constant gain

Abstract

The utility model relates to a continuously adjustable analog phase shifter of gain constancy relates to an amplifier, in order to solve the problem that the phase cannot be continuously automatically regulated and the gain is strictly invariable in the existing phase shift method. The opposite phase input of the operational amplifier is connected with one end of resistance R4 and one end of resistance R5, the same phase input of the operational amplifier is connected with one end of resistance R1 and one end of photosensitive resistance R3, the output of the operational amplifier is connected with the other end of resistance R5, and the output of the operational amplifier is used as the phase shift signal output end, the other end of resistance R4 is connected with the other end of resistance R1 and one end of resistance R2 simultaneously, and the other end of resistance R4 is used as the phase shift signal input end, the other end of resistance R2 is connected with the other end of photosensitive resistance R3, the positive pole of the light emitting device of the photoelectric coupling resistance tube is the phase shift control end, and the negative pole of the light emitting device is grounded. The beneficial effect is that the continuous automatic regulation of signal is realized, and the gain is invariable.

Description

Technical Field

[0001] This utility model relates to an amplifier. Background Technology

[0002] In analog signal processing, it is often necessary to adjust the phase angle of the signal during operation. This is achieved by controllably changing the circuit parameters to induce a phase shift in the signal, thereby adjusting the phase of the signal while keeping the circuit gain (amplification factor) constant.

[0003] For example, in a high-precision inductive synchro angle measurement system, it is necessary to keep the phases of the sine and cosine output signals of the two-phase excitation power supply constant. Since the distortion error of the two signals is required to be small at the same time, multi-stage filtering is required, including bandpass filtering. The combined effect of various factors and filtering stages causes the two-phase signals to drift with time and temperature, and the phases of the two phases also change uncontrollably. Through the phase detection stage (phase detector), the drift difference of the two phase angles is detected. That is, the two sine wave (sine and cosine) signals that were originally 90° out of phase are no longer 90° out of phase after the phase drift, but are at an angle near 90°. The phase detection result is used to drive an amplifier with controllable phase shift and constant gain to shift the phases of the two sine signals so that the two phases still maintain a 90° phase difference.

[0004] In analog signal processing circuits, there are various methods to achieve phase shifting. For example, phase shifting can be achieved in a phase-locked loop (PLL). Different resistors are often used to complete analog signal processing. Digital methods mainly achieve phase shifting by adding or subtracting frequency divider pulses. These methods cannot continuously and automatically adjust the phase, and analog phase shifting schemes are often accompanied by gain changes. Utility Model Content

[0005] The purpose of this invention is to solve the problem that existing phase shifting methods cannot continuously and automatically adjust the phase while maintaining a strictly constant gain. It proposes a continuously adjustable analog phase shifter with constant gain.

[0006] The present invention provides a continuously adjustable analog phase shifter with constant gain, comprising an operational amplifier T1, resistors R1, R2, R4, and R5, and an optocoupler G1.

[0007] The inverting input terminal of the operational amplifier T1 is connected to one end of resistor R4 and one end of resistor R5; the non-inverting input terminal of the operational amplifier T1 is connected to one end of resistor R1 and one end of photoresistor R3 of optocoupler G1; the output terminal of the operational amplifier T1 is connected to the other end of resistor R5, and the output terminal of the operational amplifier T1 serves as the phase-shifting signal output terminal.

[0008] The other end of resistor R4 is connected to both the other end of resistor R1 and one end of resistor R2, and the other end of resistor R4 serves as the input terminal of the phase-shift signal.

[0009] The other end of resistor R2 is connected to the other end of photoresistor R3 of optocoupler resistor G1.

[0010] The positive terminal of the light-emitting device of the optocoupler resistor G1 is the phase-shift control terminal; the negative terminal of the light-emitting device of the optocoupler resistor G1 is grounded.

[0011] Furthermore, it also includes controlling the current source;

[0012] The control current source is electrically connected to the positive terminal of the light-emitting device of the optocoupler resistor G1; the control current source is used to adjust the light intensity of the light-emitting device.

[0013] Furthermore, the control current source is a programmable current source.

[0014] Furthermore, it also includes capacitor C1;

[0015] One end of capacitor C1 is connected to the non-inverting input of operational amplifier T1; the other end of capacitor C1 is connected to the negative terminal of the light-emitting device of optocoupler resistor G1.

[0016] Furthermore, the optocoupler G1 is an integrated surface-mount device, and the dark resistance of the photoresistor R3 is ≥1MΩ, and the light resistance is ≤500Ω.

[0017] Furthermore, the light-emitting device of the optocoupler resistor G1 is a light-emitting diode D1.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] The present invention provides a continuously adjustable analog phase shifter with constant gain, which can determine the sensitivity of signal phase adjustment as needed; the signal has almost no additional amplitude change when adjusting the phase, that is, the gain remains unchanged; the circuit is simple and easy to debug; the circuit works reliably; the phase shift adjustment is convenient to drive; and it realizes continuous automatic adjustment of the passing signal with strictly constant gain. Attached Figure Description

[0020] Figure 1 This is a circuit diagram of a continuously adjustable analog phase shifter with constant gain, as described in Specific Implementation Method 1. Detailed Implementation

[0021] Specific Implementation Method 1: Combination Figure 1This embodiment describes a continuously adjustable analog phase shifter with constant gain, comprising an operational amplifier T1, resistors R1, R2, R4, R5, and an optocoupler G1.

[0022] The inverting input terminal of the operational amplifier T1 is connected to one end of resistor R4 and one end of resistor R5; the non-inverting input terminal of the operational amplifier T1 is connected to one end of resistor R1 and one end of photoresistor R3 of optocoupler G1; the output terminal of the operational amplifier T1 is connected to the other end of resistor R5, and the output terminal of the operational amplifier T1 serves as the phase-shifting signal output terminal.

[0023] The other end of resistor R4 is connected to both the other end of resistor R1 and one end of resistor R2, and the other end of resistor R4 serves as the input terminal of the phase-shift signal.

[0024] The other end of resistor R2 is connected to the other end of photoresistor R3 of optocoupler resistor G1.

[0025] The positive terminal of the light-emitting device of the optocoupler resistor G1 is the phase-shift control terminal; the negative terminal of the light-emitting device of the optocoupler resistor G1 is grounded.

[0026] In this embodiment, by adjusting the input current at the phase-shift control terminal, the phase angle can be adjusted to lead or lag. By changing the values ​​of resistors R1, R2, R4, and R5, and in conjunction with changing the illuminance of the light-emitting device, the photoresistor R3 can be changed, thereby altering the sensitivity of the phase-shifting circuit to changes in the photoresistor R3. The circuit described above achieves phase shifting of an analog signal with constant gain. The phase is adjusted via the photoresistor R3, eliminating mechanical contacts, resulting in fast response and long lifespan. The overall circuit structure is simple, easy to debug, and suitable for phase fine-tuning in analog signal processing systems. The output signal exhibits no additional amplitude changes and maintains consistent gain.

[0027] Specific Implementation Method Two: This implementation method further defines the continuously adjustable analog phase shifter with constant gain described in Specific Implementation Method One. In this implementation method, a control current source is also included.

[0028] The control current source is electrically connected to the positive terminal of the light-emitting device of the optocoupler resistor G1; the control current source is used to adjust the light intensity of the light-emitting device.

[0029] In this embodiment, the light intensity of the light-emitting device is adjusted by controlling the current source to generate current. The current source can be adjusted remotely or automatically, supporting a closed-loop control system, improving system integration and automation level, and is suitable for intelligent measurement and control systems.

[0030] Specific Implementation Method 3: This implementation method further defines the continuously adjustable analog phase shifter with constant gain described in Specific Implementation Method 2. In this implementation method, the control current source is a programmable current source.

[0031] In this embodiment, the programmable current source supports digital control interfaces (such as MCU, FPGA) to facilitate system integration; it enables software-defined phase adjustment to adapt to complex control strategies; and it improves adjustment accuracy and repeatability, making the phase shifter suitable for high-precision measurement and feedback systems.

[0032] Specific Implementation Method Four: This implementation method further defines the continuously adjustable analog phase shifter with constant gain described in Specific Implementation Method One. In this implementation method, capacitor C1 is also included.

[0033] One end of capacitor C1 is connected to the non-inverting input of operational amplifier T1; the other end of capacitor C1 is connected to the negative terminal of the light-emitting device of optocoupler resistor G1.

[0034] In this embodiment, capacitor C1 is used to suppress high-frequency noise, improve signal stability, enhance frequency response characteristics, strengthen the circuit's anti-interference capability, and help smooth the phase adjustment process, avoiding sudden changes or oscillations.

[0035] Specific Implementation Method 5: This implementation method further defines the continuously adjustable analog phase shifter with constant gain described in Specific Implementation Method 1. In this implementation method, the optocoupler resistor G1 is an integrated surface mount device, and the dark resistance of the photoresistor R3 is ≥1MΩ and the bright resistance is ≤500Ω.

[0036] In this embodiment, the integrated surface mount device is small in size and easy to integrate, making it suitable for modern SMT processes; the photoresistor R3 has a wide resistance range and high adjustment sensitivity; the high dark-to-light resistance ratio ensures a wide phase shift range and high control accuracy; therefore, the above settings can improve system reliability and consistency, making it suitable for mass production.

[0037] Specific Implementation Method Six: This implementation method further defines the continuously adjustable analog phase shifter with constant gain described in Specific Implementation Method One. In this implementation method, the light-emitting device of the optocoupler resistor G1 is a light-emitting diode D1.

[0038] In this embodiment, the light-emitting diode D1 has the advantages of low cost, fast response, long life, easy driving, small control current, low power consumption, and good linearity when matched with the photoresistor, which is conducive to achieving smooth phase shift; in addition, the light-emitting diode D1 has strong versatility, which facilitates device selection and maintenance.

[0039] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. A continuously adjustable analog phase shifter with constant gain, characterized in that, This includes operational amplifier T1, resistors R1, R2, R4, and R5, and optocoupler G1; The inverting input terminal of the operational amplifier T1 is connected to one end of resistor R4 and one end of resistor R5; the non-inverting input terminal of the operational amplifier T1 is connected to one end of resistor R1 and one end of photoresistor R3 of optocoupler G1; the output terminal of the operational amplifier T1 is connected to the other end of resistor R5, and the output terminal of the operational amplifier T1 serves as the phase-shifting signal output terminal. The other end of resistor R4 is connected to both the other end of resistor R1 and one end of resistor R2, and the other end of resistor R4 serves as the input terminal of the phase-shift signal. The other end of resistor R2 is connected to the other end of photoresistor R3 of optocoupler resistor G1. The positive terminal of the light-emitting device of the optocoupler resistor G1 is the phase-shift control terminal; the negative terminal of the light-emitting device of the optocoupler resistor G1 is grounded.

2. The continuously adjustable analog phase shifter with constant gain according to claim 1, characterized in that, It also includes controlling the current source; The control current source is electrically connected to the positive terminal of the light-emitting device of the optocoupler resistor G1; The control current source is used to adjust the light intensity of the light-emitting device.

3. A continuously adjustable analog phase shifter with constant gain according to claim 2, characterized in that, The control current source is a programmable current source.

4. A continuously adjustable analog phase shifter with constant gain according to claim 1, characterized in that, It also includes capacitor C1; One end of capacitor C1 is connected to the non-inverting input of operational amplifier T1; the other end of capacitor C1 is connected to the negative terminal of the light-emitting device of optocoupler resistor G1.

5. A continuously adjustable analog phase shifter with constant gain according to claim 1, characterized in that, The optocoupler G1 is an integrated surface-mount device, and the dark resistance of the photoresistor R3 is ≥1MΩ and the light resistance is ≤500Ω.

6. A continuously adjustable analog phase shifter with constant gain according to claim 1, characterized in that, The light-emitting device of the optocoupler resistor G1 is a light-emitting diode D1.

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