A voltage stabilizing circuit

Abstract

The present invention relates to the technical field of voltage stabilizing circuits, and provides a voltage stabilizing circuit. A main feedback detection circuit and a sub-feedback detection circuit connected in parallel are arranged to respectively detect the output voltage of the circuit in a load state and the no-load voltage in a no-load state, and to use two detection loops to specifically feedback the voltage changes of the voltage stabilizing circuit in a load state and in a no-load state; by arranging a first voltage detection terminal at a voltage output terminal of a transformer, the output voltage can be detected at the first time the transformer outputs; and by connecting the second voltage detection terminal to the no-load voltage output terminal, the no-load voltage of the circuit when no-load is monitored in real time; and by feeding back corresponding output voltage adjustment data and no-load voltage adjustment data to a main control module at the first time, the output voltage of the voltage stabilizing circuit is stabilized within an upper and lower fluctuation range of 5%, thereby greatly improving the stability of the output voltage of the voltage stabilizing circuit.

Description

Technical Field

[0001] The present invention relates to the technical field of voltage stabilizing circuits, and in particular to a voltage stabilizing circuit. Background Art

[0002] A voltage stabilizer is a device in electronic engineering that is designed to automatically maintain a constant voltage. A voltage stabilizer includes at least a simple "feedforward" design or a negative feedback control loop. Voltage stabilizers are often used in power supply systems, working with rectifiers, electronic filters and other devices to provide a stable output voltage to microprocessors and other components. In a distributed power distribution system, a voltage stabilizer is generally installed in a substation to ensure that a stable voltage can be output to users when the output power varies.

[0003] See also Figure 1 , the traditional 431 voltage stabilization circuit collects the output voltage (the transformer output voltage after filtering by the filter circuit) by setting the sampling point at the positive output end of the power supply (the output end of the filter circuit). However, this voltage sampling feedback method cannot feedback the change of the output voltage in advance. The feedback signal (the change of the output voltage) can only be fed back to the PWM end of U1 after the bus voltage drops, and then the action of U1 is controlled under the drive of the feedback signal. In summary, the slow feedback rate causes a huge drop in the output voltage of the main output circuit, and it is impossible to ensure that the output voltage fluctuation remains within the standard fluctuation range. For example, in the dynamic response state of 0.5Hz\1Hz\2Hz\15Hz and when switching between heavy and light loads, the output voltage of the voltage regulator drops by nearly 30%. Summary of the invention

[0004] The present invention provides a voltage stabilizing circuit, which solves the technical problems that the output voltage drops seriously and the output voltage stability is low due to the untimely feedback of the feedback circuit of the existing voltage stabilizer.

[0005] In order to solve the above technical problems, the present invention provides a voltage stabilizing circuit, comprising a transformer and a main control module, and also comprising a main feedback detection circuit and a sub-feedback detection circuit connected in parallel, and a signal feedback circuit connected in series with the main feedback detection circuit and the sub-feedback detection circuit;

[0006] The first voltage detection terminal and the first feedback output terminal of the main feedback detection circuit are respectively connected to the voltage output terminal of the transformer and the signal input terminal of the signal feedback circuit;

[0007] The second voltage detection terminal and the second feedback output terminal of the auxiliary feedback detection circuit are respectively connected to the no-load voltage output terminal of the transformer and the signal input terminal of the signal feedback circuit;

[0008] The signal output end of the signal feedback circuit is connected to the voltage feedback end of the main control module, and is used to generate a first feedback signal and a second feedback signal according to the detection results of the main feedback detection circuit and the auxiliary feedback detection circuit, respectively, and feed them back to the main control module;

[0009] When the voltage stabilizing circuit is in a load state, the main feedback detection circuit detects the output voltage of the transformer through the first voltage detection terminal, obtains corresponding output voltage adjustment data and outputs it to the signal feedback circuit, the signal feedback circuit generates the first feedback signal according to the output voltage adjustment data and feeds it back to the main control module, the main control module adjusts the output pulse according to the first feedback signal, and then dynamically regulates the output voltage;

[0010] When the voltage stabilization circuit is in a no-load state, the auxiliary feedback detection circuit detects the no-load voltage of the transformer through the second voltage detection terminal, obtains corresponding no-load voltage adjustment data and outputs it to the signal feedback circuit. The signal feedback circuit generates the second feedback signal according to the no-load voltage adjustment data and feeds it back to the main control module. The main control module adjusts the output pulse according to the second feedback signal, thereby dynamically regulating the no-load voltage.

[0011] This basic scheme sets up a main feedback detection circuit and a sub-feedback detection circuit in parallel, which respectively detect the output voltage of the circuit in a loaded state and the no-load voltage in a no-load state, and uses two detection loops to specifically detect the voltage change of the feedback voltage stabilizing circuit; by setting the first voltage detection terminal at the voltage output terminal of the transformer, the output voltage can be detected at the first time the transformer outputs, and combined with a small-capacity capacitor, the sensitivity and reaction rate of the signal feedback are greatly improved; and by connecting the second voltage detection terminal to the no-load voltage output terminal, the no-load voltage of the circuit when it is no-load is monitored in real time; when a change in the voltage value is detected, the main feedback detection circuit and the sub-feedback detection circuit are driven to switch to the corresponding working mode in time, and the corresponding output voltage adjustment data and no-load voltage adjustment data are fed back to the main control module at the first time, so that the output voltage of the voltage stabilizing circuit is stabilized within an upper and lower fluctuation range of 5%, thereby greatly improving the stability of the output voltage of the voltage stabilizing circuit.

[0012] In a further embodiment, the main feedback detection circuit includes a first sampling module, a first detection module and a first isolation module connected in sequence; the sampling end of the first sampling module is the first voltage detection end; one end of the first isolation module is connected to the first detection module, and the other end is connected to the signal feedback circuit;

[0013] The first sampling module is used to collect the output voltage of the transformer voltage output terminal;

[0014] The first detection module is used to compare and calculate the output voltage with a first preset voltage threshold to obtain the output voltage adjustment data;

[0015] The first isolation module is used to isolate the feedback loop of the auxiliary feedback detection circuit to prevent data cross interference.

[0016] In this solution, a first sampling module is arranged to detect the output voltage of the voltage output terminal of the transformer in real time, thereby realizing high-precision and high-efficiency detection of the output voltage fluctuation of the voltage stabilizing circuit. Through the voltage comparison function of the first detection module, the output voltage is accurately compared with the first preset voltage threshold, and the corresponding output voltage adjustment data is obtained, so that the output voltage is adjusted at the first time, which greatly improves the stability of the output voltage of the voltage stabilizing circuit; and the first isolation module is arranged to isolate the main feedback detection circuit and the auxiliary feedback detection circuit, thereby effectively preventing data confusion caused by the crossover of data of the two sets of feedback loops.

[0017] In a further embodiment, the secondary feedback detection circuit includes a second detection module and a second isolation module; one end of the second detection module is connected to the second voltage detection end, and the other end is connected to the signal feedback circuit through the second isolation module;

[0018] The second detection module is used to compare and calculate the no-load voltage with a second preset voltage threshold to obtain the no-load voltage adjustment data;

[0019] The second isolation module is used to isolate the feedback loop of the main feedback detection circuit to prevent data cross interference.

[0020] This solution uses the voltage comparison function of the second detection module to accurately compare the no-load voltage with the second preset voltage threshold and obtain the corresponding no-load voltage adjustment data, so as to adjust the control voltage in the first time so that the no-load voltage is stabilized within a safe fluctuation range, effectively preventing circuit losses caused by excessive no-load voltage and reducing the power loss of the voltage stabilization circuit in the sleep state; and also isolates the main feedback detection circuit and the auxiliary feedback detection circuit by setting a second isolation module, effectively preventing data confusion caused by the crossover of data between the two sets of feedback loops.

[0021] In a further embodiment, the first detection module includes a first voltage dividing component and a first voltage comparing component connected in series; one end of the first voltage dividing component is connected to the first sampling module, and the other end is connected to the input end of the first voltage comparing component; the output end of the first voltage comparing component is connected to the first isolation module;

[0022] The first voltage dividing component is used to perform voltage dividing processing on the collected output voltage to obtain a first collected voltage value;

[0023] The first voltage comparison component is used to compare the first collected voltage value with a first preset voltage threshold to obtain the output voltage adjustment data.

[0024] In this solution, a first voltage-dividing component is provided to divide the high output voltage obtained by the first sampling module to obtain a first collected voltage value of a low voltage, so that the first voltage comparison component can obtain output voltage adjustment data corresponding to the output voltage only by comparing the first collected voltage value with a first preset voltage threshold, and reflect the high voltage with the low voltage, and see the big from the small, thereby reducing the load power of the feedback circuit and achieving accurate feedback of the output voltage.

[0025] In a further embodiment, the second detection module includes a second voltage-dividing component and a second voltage-comparing component connected in series, and a first filtering component connected in parallel with the second voltage-dividing component; one end of the second voltage-dividing component is connected to the second voltage detection end, and the other end is connected to the second voltage-comparing component; one end of the first filtering component is connected to the second voltage-dividing component, and the other end is grounded;

[0026] The second voltage dividing component is used to perform voltage dividing processing on the collected no-load voltage to obtain a second collected voltage value;

[0027] The first filtering component is used to filter the second collected voltage value to avoid false triggering of the second voltage comparison component;

[0028] The second voltage comparison component is used to compare the second collected voltage value with a second preset voltage threshold to obtain the no-load voltage adjustment data.

[0029] In this solution, a second voltage-dividing component is arranged to divide the acquired high-voltage output voltage to obtain a second collected voltage value of a low voltage, so that the second voltage comparison component can obtain the no-load voltage adjustment data corresponding to the no-load voltage only by comparing the second collected voltage value with the second preset voltage threshold, thereby reflecting the high voltage with the low voltage and seeing the big from the small, thereby reducing the load power of the feedback circuit and achieving accurate feedback of the output voltage.

[0030] In a further embodiment, the first voltage comparison component and the second voltage comparison component have the same circuit structure, both comprising a voltage-dividing resistor and a voltage-stabilizing element connected in series; one end of the voltage-stabilizing element is grounded, its input end is connected to the voltage-dividing component, and its output end is connected to the signal feedback circuit through the voltage-dividing resistor;

[0031] When the input voltage at the input end of the voltage stabilizing element meets the voltage adjustment condition, the output end thereof is connected to the ground end, thereby connecting the signal feedback circuit, the voltage dividing component and the ground loop of the voltage stabilizing element, and changing the output current of the ground loop;

[0032] The voltage adjustment condition includes a main feedback condition and a sub-feedback condition;

[0033] The main feedback condition is that the first collected voltage value is higher than a first preset voltage threshold;

[0034] The secondary feedback condition is that the second collected voltage value is lower than a second preset voltage threshold.

[0035] The voltage stabilizing element includes an operational amplifier comparator or a voltage stabilizer.

[0036] This solution utilizes the comparison function of the voltage stabilizing element to compare the output voltage, no-load voltage with the first preset voltage threshold and the second preset voltage threshold in real time, accurately obtains the current voltage output fluctuation data of the voltage stabilizing circuit, and realizes the conduction of the signal feedback circuit, the voltage divider component and the grounding loop of the voltage stabilizing element by connecting its own output terminal and the ground terminal, and then dynamically adjusts the voltage output pulse (i.e., the output voltage or no-load voltage) of the voltage regulator by changing the output current of the voltage feedback terminal on the main control module.

[0037] In a further implementation scheme, the first sampling module includes a first diode and a filter capacitor; the positive electrode of the first diode is connected to the voltage output end of the transformer, and the negative electrode is connected to the first detection module; one end of the filter capacitor is connected to the negative electrode of the first diode, and the other end is grounded.

[0038] This solution uses a rectifier diode and a small-capacity filter capacitor, and uses their rectification and filtering functions to reduce the pulsation of the output voltage; the small-capacity characteristics of the filter capacitor are used to greatly improve the feedback sensitivity and feedback rate of the main feedback detection circuit, thereby achieving timely adjustment of the output voltage of the voltage stabilization circuit, making its output voltage more stable.

[0039] In a further embodiment, the signal feedback circuit includes a third voltage divider component and a photocoupler connected in series; the photocoupler is used to generate the first feedback signal and the second feedback signal according to the output voltage adjustment data and the no-load voltage adjustment data and feed them back to the main control module.

[0040] This solution ensures that when the output of the voltage stabilization circuit is stable (when the voltage stabilization elements in the main feedback detection circuit and the auxiliary feedback detection circuit are not conducting), the feedback voltage at the signal input terminal can meet the minimum conduction voltage of the photocoupler, thereby ensuring conduction between the feedback circuit and the main control module.

[0041] In a further embodiment, the first preset voltage threshold is less than the second preset voltage threshold.

[0042] This solution sets the first preset voltage threshold of the main feedback detection circuit to be smaller than the second preset voltage threshold of the auxiliary feedback detection circuit, and quickly and intuitively obtains a start signal through the relationship between the detected output voltage or no-load voltage and the first preset voltage threshold or the second preset voltage threshold, thereby driving the first voltage comparison component or the second voltage comparison component to switch from the sleep mode to the working mode, and feedback and adjust the output voltage or no-load voltage.

[0043] In a further embodiment, the first isolation module and the second isolation module are respectively a second diode and a third diode, and the anodes of the second diode and the third diode are both connected to the signal feedback circuit.

[0044] This solution uses the unidirectional conduction characteristics of the diode to set up the first isolation module and the second isolation module, while respectively realizing the signal feedback between the main feedback detection circuit and the auxiliary feedback detection circuit and the main control module, it also avoids data confusion caused by the crossover of data between the two sets of feedback loops. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a hardware circuit diagram of the prior art provided by an embodiment of the present invention;

[0046] Figure 2 It is a system framework diagram of a partial structure of a voltage stabilizing circuit provided by an embodiment of the present invention;

[0047] Figure 3 The embodiment of the present invention provides Figure 2 Hardware circuit diagram;

[0048] Figure 4 is a complete hardware circuit diagram of a voltage stabilizing circuit provided by an embodiment of the present invention;

[0049] Among them: a first voltage detection terminal V1, a first voltage detection terminal V2, a voltage feedback terminal V3, a main control module U1; a main feedback detection circuit 1, a first sampling module 11, a first detection module 12, a first voltage dividing component 121, a first voltage comparing component 122; a first isolation module 13; a secondary feedback detection circuit 2, a second detection module 21, a second voltage dividing component 211, a second voltage comparing component 212, a first filtering component 213; a second isolation module 22; a signal feedback circuit 3, a third voltage dividing component 31, and a photoelectric coupler U2. DETAILED DESCRIPTION

[0050] The following specifically illustrates the implementation mode of the present invention in conjunction with the accompanying drawings. The embodiments are provided for illustrative purposes only and cannot be understood as limiting the present invention. The accompanying drawings are provided for reference and illustration only and do not constitute a limitation on the scope of patent protection of the present invention, because many changes can be made to the present invention without departing from the spirit and scope of the present invention.

[0051] An embodiment of the present invention provides a voltage stabilizing circuit, such as Figure 2 , Figure 3 , Figure 4 As shown, in this embodiment, it includes a transformer T1 and a main control module U1, and also includes a main feedback detection circuit 1 and a sub-feedback detection circuit 2 connected in parallel, and a signal feedback circuit 3 connected in series with the main feedback detection circuit 1 and the sub-feedback detection circuit 2;

[0052] The first voltage detection terminal V1 and the first feedback output terminal of the main feedback detection circuit 1 are connected to the voltage output terminal of the transformer T1 and the signal input terminal of the signal feedback circuit 3 respectively;

[0053] The second voltage detection terminal V2 and the second feedback output terminal of the auxiliary feedback detection circuit 2 are respectively connected to the no-load voltage output terminal of the transformer T1 and the signal input terminal of the signal feedback circuit 3;

[0054] The signal output end of the signal feedback circuit 3 is connected to the voltage feedback end V3 of the main control module U1, and is used to generate a first feedback signal and a second feedback signal according to the detection results of the main feedback detection circuit 1 and the auxiliary feedback detection circuit 2, respectively, and feed them back to the main control module U1;

[0055] When the voltage stabilizing circuit is in a load state, the main feedback detection circuit 1 detects the output voltage of the transformer T1 through the first voltage detection terminal V1, obtains corresponding output voltage adjustment data and outputs it to the signal feedback circuit 3. The signal feedback circuit 3 generates the first feedback signal according to the output voltage adjustment data and feeds it back to the main control module U1. The main control module U1 adjusts the output pulse according to the first feedback signal, thereby dynamically regulating the output voltage.

[0056] When the voltage stabilizing circuit is in a no-load state, the auxiliary feedback detection circuit 2 detects the no-load voltage of the transformer T1 through the second voltage detection terminal V2, obtains the corresponding no-load voltage adjustment data and outputs it to the signal feedback circuit 3. The signal feedback circuit 3 generates the second feedback signal according to the no-load voltage adjustment data and feeds it back to the main control module U1. The main control module U1 adjusts the output pulse according to the second feedback signal, thereby dynamically regulating the no-load voltage.

[0057] In this embodiment, a main feedback detection circuit 1 and a sub-feedback detection circuit 2 are arranged in parallel to detect the output voltage of the circuit in a load state and the no-load voltage in a no-load state, respectively, and the voltage change of the feedback voltage stabilizing circuit is detected in a targeted manner by using two detection loops; by arranging the first voltage detection terminal V1 at the voltage output terminal of the transformer T1, the output voltage can be detected at the first time when the transformer T1 outputs, and combined with a small-capacity capacitor, the sensitivity and reaction rate of the signal feedback are greatly improved; and by connecting the second voltage detection terminal V2 to the no-load voltage output terminal, the no-load voltage of the circuit when it is no-load is monitored in real time; when a change in the voltage value is detected, the main feedback detection circuit 1 and the sub-feedback detection circuit 2 are driven to switch to the corresponding working mode in time, and the corresponding output voltage adjustment data and no-load voltage adjustment data are fed back to the main control module U1 at the first time, so that the output voltage of the voltage stabilizing circuit is stabilized within the upper and lower fluctuation range of 5%, thereby greatly improving the stability of the output voltage of the voltage stabilizing circuit.

[0058] In this embodiment, the main feedback detection circuit 1 includes a first sampling module 11, a first detection module 12 and a first isolation module 13 connected in sequence; the sampling end of the first sampling module 11 is the first voltage detection end V1; one end of the first isolation module 13 is connected to the first detection module 12, and the other end is connected to the signal feedback circuit 3;

[0059] The first sampling module 11 is used to collect the output voltage of the voltage output end of the transformer T1;

[0060] The first detection module 12 is used to compare and calculate the output voltage with a first preset voltage threshold to obtain the output voltage adjustment data;

[0061] The first isolation module 13 is used to isolate the feedback loop of the auxiliary feedback detection circuit 2 to prevent data cross interference.

[0062] In this embodiment, a first sampling module 11 is provided to detect the output voltage of the voltage output terminal of the transformer T1 in real time, thereby realizing high-precision and high-efficiency detection of the output voltage fluctuation of the voltage stabilizing circuit. Through the voltage comparison function of the first detection module 12, the output voltage is accurately compared with the first preset voltage threshold, and the corresponding output voltage adjustment data is obtained, so that the output voltage is adjusted at the first time, which greatly improves the stability of the output voltage of the voltage stabilizing circuit; and the first isolation module 13 is provided to isolate the main feedback detection circuit 1 and the auxiliary feedback detection circuit 2, thereby effectively preventing data confusion caused by the crossover of data of the two groups of feedback loops.

[0063] In this embodiment, the first detection module 12 includes a first voltage dividing component 121 and a first voltage comparing component 122 connected in series; one end of the first voltage dividing component 121 is connected to the first sampling module 11, and the other end is connected to the input end of the first voltage comparing component 122; the output end of the first voltage comparing component 122 is connected to the first isolation module 13;

[0064] The first voltage dividing component 121 is used to perform voltage dividing processing on the collected output voltage to obtain a first collected voltage value;

[0065] The first voltage comparison component 122 is used to compare the first collected voltage value with a first preset voltage threshold to obtain the output voltage adjustment data.

[0066] In this embodiment, a first voltage-dividing component 121 is provided to divide the high voltage output voltage obtained by the first sampling module 11 to obtain a first collected voltage value of a low voltage, so that the first voltage comparison component 122 can obtain output voltage adjustment data corresponding to the output voltage only by comparing the first collected voltage value with a first preset voltage threshold, and reflect the high voltage with the low voltage, and see the big from the small, thereby reducing the load power of the feedback circuit and achieving accurate feedback of the output voltage.

[0067] In this embodiment, the first sampling module 11 includes a first diode and a filter capacitor; the anode of the first diode is connected to the voltage output end of the transformer T1, and the cathode is connected to the first detection module 12; one end of the filter capacitor is connected to the cathode of the first diode, and the other end is grounded.

[0068] This embodiment uses a rectifier diode and a small-capacity filter capacitor, and utilizes their rectification and filtering functions to reduce the pulsation of the output voltage; utilizing the small-capacity characteristics of the filter capacitor, the feedback sensitivity and feedback rate of the main feedback detection circuit 1 are greatly improved, thereby achieving timely adjustment of the output voltage of the voltage stabilizing circuit, making its output voltage more stable.

[0069] In this embodiment, the auxiliary feedback detection circuit 2 includes a second detection module 21 and a second isolation module 22; one end of the second detection module 21 is connected to the second voltage detection terminal V2, and the other end is connected to the signal feedback circuit 3 through the second isolation module 22;

[0070] The second detection module 21 is used to compare and calculate the no-load voltage with a second preset voltage threshold to obtain the no-load voltage adjustment data;

[0071] The second isolation module 22 is used to isolate the feedback loop of the main feedback detection circuit 1 to prevent data cross interference.

[0072] This embodiment uses the voltage comparison function of the second detection module 21 to accurately compare the no-load voltage with the second preset voltage threshold, and obtains the corresponding no-load voltage adjustment data, so as to adjust the control voltage in the first time, so that the no-load voltage is stabilized within a safe fluctuation range, effectively preventing circuit loss caused by excessive no-load voltage and reducing the power loss of the voltage stabilizing circuit in the sleep state; and also isolates the main feedback detection circuit 1 and the auxiliary feedback detection circuit 2 by setting a second isolation module 22, effectively preventing data confusion caused by the crossover of data between the two sets of feedback loops.

[0073] In this embodiment, the second detection module 21 includes a second voltage dividing component 211 and a second voltage comparing component 212 connected in series, and a first filtering component 213 connected in parallel with the second voltage dividing component 211; one end of the second voltage dividing component 211 is connected to the second voltage detecting terminal V2, and the other end is connected to the second voltage comparing component 212; one end of the first filtering component 213 is connected to the second voltage dividing component 211, and the other end is grounded;

[0074] The second voltage dividing component 211 is used to perform voltage dividing processing on the collected no-load voltage to obtain a second collected voltage value;

[0075] The first filtering component 213 is used to filter the second collected voltage value to avoid false triggering of the second voltage comparison component 212;

[0076] The second voltage comparison component 212 is used to compare the second collected voltage value with a second preset voltage threshold to obtain the no-load voltage adjustment data.

[0077] In this embodiment, a second voltage-dividing component 211 is provided to divide the acquired high-voltage output voltage to obtain a second collected voltage value of a low voltage, so that the second voltage comparison component 212 can obtain the no-load voltage adjustment data corresponding to the no-load voltage only by comparing the second collected voltage value with the second preset voltage threshold, thereby reflecting the high voltage with the low voltage and seeing the big from the small, thereby reducing the load power of the feedback circuit and achieving accurate feedback of the output voltage.

[0078] In this embodiment, the first voltage comparison component 122 and the second voltage comparison component 212 have the same circuit structure, both comprising a voltage-dividing resistor and a voltage-stabilizing element connected in series; the voltage-stabilizing element grounding end is grounded, the input end is connected to the voltage-dividing component, and the output end is connected to the signal feedback circuit 3 through the voltage-dividing resistor;

[0079] When the input voltage at the input end of the voltage stabilizing element meets the voltage adjustment condition, the output end thereof is connected to the ground end, thereby connecting the signal feedback circuit 3, the voltage dividing component and the ground loop of the voltage stabilizing element, and changing the output current of the ground loop;

[0080] The voltage adjustment condition includes a main feedback condition and a sub-feedback condition;

[0081] The main feedback condition is that the first collected voltage value is higher than a first preset voltage threshold;

[0082] The secondary feedback condition is that the second collected voltage value is lower than a second preset voltage threshold.

[0083] The voltage stabilizing element includes but is not limited to an operational amplifier comparator and a voltage stabilizer, and the voltage stabilizer includes a TL431 voltage stabilizer and a TL432 voltage stabilizer.

[0084] This embodiment utilizes the comparison function of the voltage stabilizing element to compare the output voltage, no-load voltage with the first preset voltage threshold and the second preset voltage threshold in real time, and accurately obtains the current voltage output fluctuation data of the voltage stabilizing circuit (which is collected in real time through the first voltage detection terminal V1 or the second voltage detection terminal V2), and realizes the conduction of the grounding loop of the signal feedback circuit 3, the voltage divider component and the voltage stabilizing element by connecting its own output terminal and the ground terminal, and then dynamically adjusts the voltage output pulse (i.e., the output voltage or no-load voltage) of the voltage stabilizer by changing the output current of the voltage feedback terminal V3 on the main control module U1.

[0085] In this embodiment, the signal feedback circuit 3 includes a third voltage-dividing component 31 and a photocoupler U2 connected in series; the third voltage-dividing component 31 is used to ensure that the feedback voltage is maintained above a certain conduction threshold to prevent the photocoupler U2 from entering a dead zone; the photocoupler U2 is used to generate the first feedback signal and the second feedback signal according to the output voltage adjustment data and the no-load voltage adjustment data and feed them back to the main control module.

[0086] In this embodiment, a third voltage divider component 31 connected in series is provided on the circuits of the main feedback detection circuit 1 and the auxiliary feedback detection circuit 2 to ensure that when the output of the voltage stabilization circuit is stable (when the voltage stabilization elements in the main feedback detection circuit 1 and the auxiliary feedback detection circuit 2 are not conducting), the feedback voltage at the signal input terminal satisfies the minimum conduction voltage of the photocoupler U2, thereby ensuring conduction between the feedback circuit and the main control module U1.

[0087] In this embodiment, the first preset voltage threshold is smaller than the second preset voltage threshold.

[0088] In this embodiment, by setting the first preset voltage threshold of the main feedback detection circuit 1 to be smaller than the second preset voltage threshold of the auxiliary feedback detection circuit 2, a start signal is obtained quickly and intuitively through the relationship between the detected output voltage or no-load voltage and the first preset voltage threshold or the second preset voltage threshold, so as to drive the first voltage comparison component 122 or the second voltage comparison component 212 to switch from the sleep mode to the working mode, and to feedback and adjust the output voltage or the no-load voltage.

[0089] In this embodiment, the first isolation module 13 and the second isolation module 22 are respectively a second diode D5 and a third diode D6, and the anodes of the second diode D5 and the third diode D6 are both connected to the signal feedback circuit 3. This embodiment uses the unidirectional conduction characteristics of the diode to set the first isolation module 13 and the second isolation module 22, and while respectively realizing the signal feedback between the main feedback detection circuit 1 and the auxiliary feedback detection circuit 2 and the main control module U1, it also avoids data confusion caused by the crossover of data between the two groups of feedback loops.

[0090] See also Figure 4 In this embodiment, the photoelectric coupler U2 includes 4 ports, of which the 3rd terminal is grounded, the 4th terminal (signal output terminal) is connected to the main control module U1, and the 2nd terminal of the photoelectric coupler U2 is the signal input terminal of the signal feedback circuit 3. The third voltage divider component 31 includes a resistor R21 and a resistor R22 connected in series, one end of the R22 is connected to the no-load voltage output terminal, and the other end is connected to the resistor R21 and the 1st terminal of the photoelectric coupler U2; one end of the resistor R21 is connected to the resistor R22 and the 1st terminal of the photoelectric coupler U2, and the other end is connected to the 2nd terminal of the photoelectric coupler U2.

[0091] The main feedback detection circuit 1 includes a resistor R29, resistors R31-R33, a resistor R40, capacitors C17-C18, an anti-interference diode D5, a voltage stabilizing diode D8 and a voltage stabilizing element U3; the first sampling module 11 includes the voltage stabilizing diode D8 and the capacitor C18; the first voltage dividing component 121 includes the resistor R40, the resistors R31-R33 and the capacitor C17; the first voltage comparison component 122 includes the resistor R29 and the voltage stabilizing element U3; the first isolation module 13 includes the anti-interference diode D5.

[0092] Among them, the positive electrode of the voltage stabilizing diode D8 is connected to the voltage output end of the transformer T1, and the negative electrode is grounded and connected to the resistor R40 through the capacitor C18; the other end of the resistor R40 is connected to the input end of the voltage stabilizing element U3, the resistor R32, the resistor R33 and the capacitor C17, the other ends of the resistor R32 and the resistor R33 are grounded, the other end of the capacitor C17 is connected to the output end of the voltage stabilizing element U3 through the resistor R31, and the ground end of the voltage stabilizing element U3 is grounded; the positive electrode of the anti-interference diode D5 is connected to the 2 ends of the photoelectric coupler U2, and the negative electrode is connected to the output end of the voltage stabilizing element U3 through the resistor R29.

[0093] The secondary feedback detection circuit 2 includes a resistor R23, resistors R25 to R28, a resistor R30, capacitors C15 to C16, an anti-interference diode D6 and a voltage stabilizing element U4; the second voltage dividing component 211 includes the resistors R25 to R27, the resistor R30 and the capacitor C15; the first filtering component 213 includes the resistor 28 and the capacitor C16; the second voltage comparison component 212 includes the resistor R23 and the voltage stabilizing element U4; the second isolation module 22 includes the anti-interference diode D6.

[0094] Among them, one end of the resistor R30 is connected to the no-load voltage output end, and the other end is connected to the input end of the voltage stabilizing element U4, the resistor R25, the resistor R26, the resistor R27, and the resistor R28. The other end of the resistor R28 is grounded through the capacitor C16, and the other ends of the resistor R26 and the resistor R27 are grounded. The other end of the resistor R25 is connected to the output end of the voltage stabilizing element U4 through the capacitor C15 (the positions of the resistor R25 and the capacitor C15 can be interchanged), and the ground end of the voltage stabilizing element U4 is grounded; the positive electrode of the anti-interference diode D6 is connected to the 2 ends of the photoelectric coupler U2, and the negative electrode is connected to the output end of the voltage stabilizing element U4 through the resistor R23.

[0095] The first preset voltage threshold and the second preset voltage threshold are voltage comparison thresholds of the voltage stabilizing element U3 and the voltage stabilizing element U4, respectively; and also include a first set voltage value and a second set voltage value corresponding to the first preset voltage threshold and the second preset voltage threshold, respectively, the first set voltage value and the second set voltage value are a standard output voltage and a standard no-load voltage, respectively.

[0096] See also Figure 2 In this embodiment, the working principle of the feedback circuit is as follows:

[0097] When the circuit is in a load state, the main feedback detection circuit 1 directly obtains the output voltage of the transformer T1 through the first voltage detection terminal V1. After the output voltage is subjected to voltage stabilization filtering by the voltage stabilizing diode D8 and the capacitor C18 and voltage division processing and filtering processing by the first voltage dividing component 121, a first collected voltage value is obtained and input into the input terminal of the voltage stabilizing element U3; the voltage stabilizing element U3 compares the first collected voltage value with the first preset voltage threshold value by using its own comparison function. When the first collected voltage value is lower than the first preset voltage threshold value, the voltage stabilizing element U3 is not turned on. When the first collected voltage value is higher than the first preset voltage threshold value, its output terminal and the ground terminal are turned on, that is, the resistor R22, the 1st terminal and the 2nd terminal of the photoelectric coupler U2, the resistor R21, the anti-interference diode D5, the resistor R29 and the voltage stabilizing element U3 are turned on. At this time, the voltage stabilizing element U3 is equivalent to an equivalent resistor, and the size of its resistance value is mapped to the output voltage adjustment data. Because the total loop voltage remains unchanged, when the resistance value of the voltage stabilizing element U3 changes, the current value of the entire ground loop will also change; thereby changing the brightness of the light-emitting diode in the photocoupler U2, and the resistance value of the phototransistor changes accordingly, that is, the feedback current at the end of the photocoupler U24 changes synchronously. Finally, the output pulse is adjusted by the feedback current control main control module U1, thereby dynamically regulating the output voltage.

[0098] When the circuit is in a no-load state (the main control module U1 changes from the working mode to the sleep mode), the auxiliary feedback detection circuit 2 detects the no-load voltage output by the transformer T1 through the second voltage detection terminal V2 (the cathode of the diode D7). The no-load voltage is divided by the second voltage divider component 211 and filtered by the first filter component 213 to obtain a second collected voltage value and input it into the input end of the voltage stabilizing element U4. The voltage stabilizing element U4 compares the second collected voltage value with the second preset voltage threshold using its own comparison function. When the second collected voltage value is lower than the second voltage threshold, the voltage stabilizing element U4 is not turned on. When the second collected voltage value is higher than the second voltage threshold, its output end and the ground end are turned on, that is, the resistor R22, the 1st and 2nd ends of the photoelectric coupler U2, the resistor R21, the anti-interference diode D6, the resistor R23 and the voltage stabilizing element U4 are turned on. At this time, the voltage stabilizing element U4 is equivalent to an equivalent resistor, and the size of its resistance value is mapped to the no-load voltage adjustment data. Because the total loop voltage remains unchanged, when the resistance value of the voltage stabilizing element U4 changes, the current value of the entire ground loop will also change; thereby changing the brightness of the light-emitting diode in the photocoupler U2, and the resistance value of the phototransistor changes accordingly, that is, the feedback current at the end of the photocoupler U24 changes synchronously. Finally, the main control module U1 is controlled by the feedback current to adjust the output pulse, effectively controlling the no-load voltage within the set range.

[0099] When switching from no-load to load mode, the main control module U1 switches to working mode, and its output frequency is switched to high frequency (frequency greater than 30KHZ). At this time, the voltage across the capacitor C18 is stabilized at the first preset voltage threshold, and the output voltage is stabilized within the fluctuation range of the first set voltage value under the regulation of the first feedback signal.

[0100] When the load switches to the no-load mode, the main control module U1 switches to the sleep mode, and its output frequency switches to a low frequency (the frequency depends on the internal setting of the main control module U1); the voltage frequency across the capacitor C18 is synchronized with the frequency of the main control module and does not exceed the second set voltage threshold. At the same time, because of the voltage fluctuation across the capacitor C18, the auxiliary feedback detection circuit 2 is driven to generate the no-load voltage adjustment data and feed it back to the main control module U1 until the no-load voltage is stabilized within the fluctuation range of the second set voltage value.

[0101] The voltage feedback compensation is performed in this cycle.

[0102] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A voltage stabilizing circuit, comprising a transformer and a main control module, characterized in that: It also includes a main feedback detection circuit and a sub-feedback detection circuit connected in parallel, and a signal feedback circuit connected in series with the main feedback detection circuit and the sub-feedback detection circuit; The first voltage detection terminal and the first feedback output terminal of the main feedback detection circuit are respectively connected to the voltage output terminal of the transformer and the signal input terminal of the signal feedback circuit; The second voltage detection terminal and the second feedback output terminal of the auxiliary feedback detection circuit are respectively connected to the no-load voltage output terminal of the transformer and the signal input terminal of the signal feedback circuit; The signal output end of the signal feedback circuit is connected to the voltage feedback end of the main control module, and is used to generate a first feedback signal and a second feedback signal according to the detection results of the main feedback detection circuit and the auxiliary feedback detection circuit, respectively, and feed them back to the main control module; When the voltage stabilizing circuit is in a load state, the main feedback detection circuit detects the output voltage of the transformer through the first voltage detection terminal, obtains corresponding output voltage adjustment data and outputs it to the signal feedback circuit, the signal feedback circuit generates the first feedback signal according to the output voltage adjustment data and feeds it back to the main control module, the main control module adjusts the output pulse according to the first feedback signal, and then dynamically regulates the output voltage; When the voltage stabilization circuit is in a no-load state, the auxiliary feedback detection circuit detects the no-load voltage of the transformer through the second voltage detection terminal, obtains corresponding no-load voltage adjustment data and outputs it to the signal feedback circuit, the signal feedback circuit generates the second feedback signal according to the no-load voltage adjustment data and feeds it back to the main control module, the main control module adjusts the output pulse according to the second feedback signal, and then dynamically regulates the no-load voltage; The main feedback detection circuit comprises a first sampling module, a first detection module and a first isolation module which are connected in sequence; the sampling end of the first sampling module is the first voltage detection end; one end of the first isolation module is connected to the first detection module, and the other end is connected to the signal feedback circuit; The first sampling module is used to collect the output voltage of the transformer voltage output terminal; The first detection module is used to compare and calculate the output voltage with a first preset voltage threshold to obtain the output voltage adjustment data; The first isolation module is used to isolate the feedback loop of the auxiliary feedback detection circuit to prevent data cross interference; The auxiliary feedback detection circuit includes a second detection module and a second isolation module; one end of the second detection module is connected to the second voltage detection end, and the other end is connected to the signal feedback circuit through the second isolation module; The second detection module is used to compare and calculate the no-load voltage with a second preset voltage threshold to obtain the no-load voltage adjustment data; The second isolation module is used to isolate the feedback loop of the main feedback detection circuit to prevent data cross interference; The first detection module comprises a first voltage dividing component and a first voltage comparing component connected in series; one end of the first voltage dividing component is connected to the first sampling module, and the other end is connected to the input end of the first voltage comparing component; the output end of the first voltage comparing component is connected to the first isolation module; The first voltage dividing component is used to perform voltage dividing processing on the collected output voltage to obtain a first collected voltage value; The first voltage comparison component is used to compare the first collected voltage value with a first preset voltage threshold to obtain the output voltage adjustment data; The second detection module comprises a second voltage divider component and a second voltage comparison component connected in series, and a first filter component connected in parallel with the second voltage divider component; one end of the second voltage divider component is connected to the second voltage detection end, and the other end is connected to the second voltage comparison component; one end of the first filter component is connected to the second voltage divider component, and the other end is grounded; The second voltage dividing component is used to perform voltage dividing processing on the collected no-load voltage to obtain a second collected voltage value; The first filtering component is used to filter the second collected voltage value to avoid false triggering of the second voltage comparison component; The second voltage comparison component is used to compare the second collected voltage value with a second preset voltage threshold to obtain the no-load voltage adjustment data; The signal feedback circuit includes a third voltage-dividing component and a photoelectric coupler connected in series; the photoelectric coupler is used to generate the first feedback signal and the second feedback signal according to the output voltage adjustment data and the no-load voltage adjustment data and feed them back to the main control module.

2. A voltage stabilizing circuit as claimed in claim 1, characterized in that: The first voltage comparison component and the second voltage comparison component have the same circuit structure, and both include a voltage-dividing resistor and a voltage-stabilizing element connected in series; the grounding end of the voltage-stabilizing element is grounded, the input end is connected to the voltage-dividing component, and the output end is connected to the signal feedback circuit through the voltage-dividing resistor; When the input voltage at the input end of the voltage stabilizing element meets the voltage adjustment condition, the output end thereof is connected to the ground end, thereby connecting the signal feedback circuit, the voltage dividing component and the ground loop of the voltage stabilizing element, and changing the output current of the ground loop; The voltage adjustment condition includes a main feedback condition and a sub-feedback condition; The main feedback condition is that the first collected voltage value is higher than a first preset voltage threshold; The secondary feedback condition is that the second collected voltage value is lower than a second preset voltage threshold.

3. A voltage stabilizing circuit as claimed in claim 1, characterized in that: The first sampling module includes a first diode and a filter capacitor; the anode of the first diode is connected to the voltage output end of the transformer, and the cathode is connected to the first detection module; one end of the filter capacitor is connected to the cathode of the first diode, and the other end is grounded.

4. A voltage stabilizing circuit as claimed in claim 2, characterized in that: The first preset voltage threshold is less than the second preset voltage threshold; and the voltage stabilizing element includes an operational amplifier comparator and a voltage stabilizer.

5. A voltage stabilizing circuit as claimed in claim 1, characterized in that: The first isolation module and the second isolation module are respectively a second diode and a third diode, and anodes of the second diode and the third diode are both connected to the signal feedback circuit.

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