A rectangular wave shaping circuit and electrical stimulation device

Abstract

The present application discloses a rectangular wave shaping circuit and an electrical stimulation device, comprising a first shaping circuit, a second shaping circuit, and an output terminal; the first shaping circuit comprises a first transformer, a first diode, and a first switch; the output terminal is connected in parallel to the two ends of the secondary coil of the first transformer, the first diode and the first switch are connected in series between the secondary coil of the first transformer and the output terminal, and when the first switch is closed, the rectangular wave shaping circuit outputs a positive half-axis waveform; the second shaping circuit comprises a second transformer, a second diode, and a second switch; the output terminal is connected in parallel to the two ends of the secondary coil of the second transformer, the second diode and the second switch are connected in series between the secondary coil of the second transformer and the output terminal, and when the second switch is closed, the rectangular wave shaping circuit outputs a negative half-axis waveform. The rectangular wave shaping circuit can weaken the interference of reverse pulses, obtain a pure rectangular wave, and can meet the requirements of outputting positive and negative half-axis waveforms.

Description

Technical Field

[0001] The present application relates to the technical field of electrical stimulation therapy, and in particular to a rectangular wave shaping circuit; and also to an electrical stimulation device. Background Art

[0002] Rectangular waves are widely found in digital circuits. Electronic components sequentially generate two levels, high and low, to form a complete rectangular wave signal. The total duration of the two levels is called the period, and the difference between the two levels is called the amplitude. By superimposing rectangular waves with different amplitudes and periods, a variety of waveforms can be obtained, such as triangle waves and trapezoidal waves. Different waveforms can produce different electrical stimulations in the human body. By developing specialized waveform combinations, the goal of treating or alleviating diseases can be achieved. Due to the special nature of muscle stimulation and electrotherapy products, the waveform requirements are becoming more stringent and diverse.

[0003] When it comes to rectangular wave shaping, traditional technical solutions introduce a reverse pulse signal into each cycle of the transformer's output waveforms of varying amplitudes due to the self-induced electromotive force. This results in poor waveform quality and the inability to produce a pure waveform. Specifically, when the transformer outputs a positive rectangular wave, after a single rectangular wave ends, the secondary coil generates a self-induced electromotive force, which creates a reverse voltage. This causes the actual output waveform to contain both the positive rectangular wave and the negative pulse waveform caused by the self-induced electromotive force. When the transformer outputs a negative rectangular wave, it also contains both the negative rectangular wave and the positive pulse waveform caused by the self-induced electromotive force.

[0004] In view of this, how to solve the above technical defects has become a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0005] The purpose of this application is to provide a rectangular wave shaping circuit that can effectively weaken the interference of reverse pulses caused by self-induced electromotive force, obtain a pure rectangular wave, and meet the requirements of outputting positive and negative half-axis waveforms. Another purpose of this application is to provide an electrical stimulation device that also has the above-mentioned technical effects.

[0006] To solve the above technical problems, the present application provides a rectangular wave shaping circuit, comprising:

[0007] a first shaping circuit, a second shaping circuit, and an output terminal;

[0008] The first shaping circuit includes a first transformer, a first diode, and a first switch; the output terminal is connected in parallel to both ends of the secondary coil of the first transformer, and the first diode and the first switch are connected in series between the secondary coil of the first transformer and the output terminal. When the first switch is closed, the secondary coil of the first transformer, the output terminal, the first diode, and the first switch form a closed loop, and the rectangular wave shaping circuit outputs a positive half-axis waveform;

[0009] The second shaping circuit includes a second transformer, a second diode, and a second switch; the output terminal is connected in parallel to the two ends of the secondary coil of the second transformer, and the second diode and the second switch are connected in series between the secondary coil of the second transformer and the output terminal. When the second switch is closed, the secondary coil of the second transformer, the output terminal, the second diode, and the second switch form a closed loop, and the rectangular wave shaping circuit outputs a negative half-axis waveform.

[0010] Optionally, the positive output end of the first shaping circuit is connected to the positive pole of the output terminal, and the negative output end of the first shaping circuit is connected to the negative pole of the output terminal; the positive output end of the second shaping circuit is connected to the negative pole of the output terminal, and the negative output end of the second shaping circuit is connected to the positive pole of the output terminal.

[0011] Optionally, the anode of the first diode is connected to the positive output end of the secondary coil of the first transformer, and the cathode of the first diode is connected to the positive electrode of the output terminal.

[0012] Optionally, the first shaping circuit further includes:

[0013] a third diode; a cathode of the third diode is connected to the positive output end of the secondary coil of the first transformer, and an anode of the third diode is connected to the negative output end of the secondary coil of the first transformer.

[0014] Optionally, the first shaping circuit further includes:

[0015] A first resistor; the first resistor is connected in parallel to both ends of the secondary coil of the first transformer.

[0016] Optionally, the anode of the second diode is connected to the positive output end of the secondary coil of the second transformer, and the cathode of the second diode is connected to the negative electrode of the output terminal.

[0017] Optionally, the second shaping circuit further includes:

[0018] A fourth diode, wherein a cathode of the fourth diode is connected to the positive output end of the secondary coil of the second transformer, and an anode of the fourth diode is connected to the negative output end of the secondary coil of the second transformer.

[0019] Optionally, the second shaping circuit further includes:

[0020] A second resistor is connected in parallel to both ends of the secondary coil of the second transformer.

[0021] Optionally, both the first switch and the second switch are solid-state relays.

[0022] In order to solve the above technical problems, the present application also provides an electrical stimulation device, including a rectangular wave shaping circuit as described in any of the above items.

[0023] The rectangular wave shaping circuit provided in this application includes:

[0024] a first shaping circuit, a second shaping circuit, and an output terminal;

[0025] The first shaping circuit includes a first transformer, a first diode, and a first switch; the output terminal is connected in parallel to both ends of the secondary coil of the first transformer, and the first diode and the first switch are connected in series between the secondary coil of the first transformer and the output terminal. When the first switch is closed, the secondary coil of the first transformer, the output terminal, the first diode, and the first switch form a closed loop, and the rectangular wave shaping circuit outputs a positive half-axis waveform;

[0026] The second shaping circuit includes a second transformer, a second diode, and a second switch; the output terminal is connected in parallel to the two ends of the secondary coil of the second transformer, and the second diode and the second switch are connected in series between the secondary coil of the second transformer and the output terminal. When the second switch is closed, the secondary coil of the second transformer, the output terminal, the second diode, and the second switch form a closed loop, and the rectangular wave shaping circuit outputs a negative half-axis waveform.

[0027] As can be seen, the rectangular wave shaping circuit provided in this application is provided with two shaping circuits, enabling the rectangular wave circuit to output a positive half-axis waveform and a negative half-axis waveform, thereby meeting the requirements for outputting positive and negative half-axis waveforms. At the same time, each shaping circuit is connected in series with a diode. By leveraging the unidirectional conductivity of the diode, the reverse pulse noise caused by the self-induced electromotive force can be effectively weakened, making the rectangular wave signal purer.

[0028] The electrical stimulation device provided in this application also has the above-mentioned technical effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the prior art and the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0030] Figure 1 A schematic diagram of a first rectangular wave shaping circuit provided in an embodiment of the present application;

[0031] Figure 2 A schematic diagram of a second rectangular wave shaping circuit provided in an embodiment of the present application;

[0032] Figure 3a A schematic diagram of the first positive half-axis waveform provided in an embodiment of the present application;

[0033] Figure 3b A schematic diagram of the first negative half-axis waveform provided in an embodiment of the present application;

[0034] Figure 4a A schematic diagram of the second positive half-axis waveform provided in an embodiment of the present application;

[0035] Figure 4b A schematic diagram of the second negative half-axis waveform provided in an embodiment of the present application;

[0036] Figure 5 A schematic diagram of a third rectangular wave shaping circuit provided in an embodiment of the present application;

[0037] Figure 6a A schematic diagram of the third positive half-axis waveform provided in an embodiment of the present application;

[0038] Figure 6b This is a schematic diagram of the third negative half-axis waveform provided in an embodiment of the present application. DETAILED DESCRIPTION

[0039] The core of this application is to provide a rectangular wave shaping circuit that can effectively weaken the interference of reverse pulses caused by self-induced electromotive force, obtain a pure rectangular wave, and meet the waveform output of positive and negative half axes. Another core of this application is to provide an electrical stimulation device, which also has the above technical effects.

[0040] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0041] Please refer to Figure 1 , Figure 1 This is a schematic diagram of a rectangular wave shaping circuit provided in an embodiment of the present application, with reference to Figure 1 As shown, the rectangular wave shaping circuit includes:

[0042] A first shaping circuit 10, a second shaping circuit 20 and an output terminal 30;

[0043] The first wave shaping circuit 10 includes a first transformer T1, a first diode D1, and a first switch K1. The output terminal 30 is connected in parallel to both ends of the secondary coil of the first transformer T1. The first diode D1 and the first switch K1 are connected in series between the secondary coil of the first transformer T1 and the output terminal 30. When the first switch K1 is closed, the secondary coil of the first transformer T1, the output terminal 30, the first diode D1, and the first switch K1 form a closed loop, and the rectangular wave shaping circuit outputs a positive half-axis waveform.

[0044] The second wave shaping circuit 20 includes a second transformer T2, a second diode D2, and a second switch K2. The output terminal 30 is connected in parallel to both ends of the secondary coil of the second transformer T2. The second diode D2 and the second switch K2 are connected in series between the secondary coil of the second transformer T2 and the output terminal 30. When the second switch K2 is closed, the secondary coil of the second transformer T2, the output terminal 30, the second diode D2, and the second switch K2 form a closed loop, and the rectangular wave shaping circuit outputs a negative half-axis waveform.

[0045] Specifically, the rectangular wave shaping circuit provided in the present application mainly includes two shaping circuits, namely a first shaping circuit 10 and a second shaping circuit 20, and an output terminal 30. The output terminal of the first shaping circuit 10 and the output terminal of the second shaping circuit 20 are both connected in parallel with the output terminal 30. Figure 2As shown, in a specific embodiment, the positive output terminal of the first shaping circuit 10 is connected to the positive electrode of the output terminal 30, and the negative output terminal of the first shaping circuit 10 is connected to the negative electrode of the output terminal 30; the positive output terminal of the second shaping circuit 20 is connected to the negative electrode of the output terminal 30, and the negative output terminal of the second shaping circuit 20 is connected to the positive electrode of the output terminal 30. In this case, when the first shaping circuit 10 and the second shaping circuit 20 are both used to output a positive semi-axis waveform, or both used to output a negative semi-axis waveform, the rectangular wave shaping circuit can output both a positive semi-axis waveform and a negative semi-axis waveform, and the first shaping circuit 10 and the second shaping circuit 20 can output simultaneously.

[0046] Specifically, the first shaping circuit 10 includes a first transformer T1, a first diode D1, and a first switch K1. The positive electrode of the output terminal 30 is connected to the positive output end of the secondary coil of the first transformer T1, and the negative electrode of the output terminal 30 is connected to the negative output end of the secondary coil of the first transformer T1. The first diode D1 and the first switch K1 are connected in series between the secondary coil of the first transformer T1 and the output terminal 30.

[0047] The rectangular wave is input to the primary coil of the first transformer T1. The first diode D1 connected in series between the secondary coil of the first transformer T1 and the output terminal 30 does not affect the first half cycle of the rectangular wave. However, since the diode has unidirectional conductivity, the first diode D1 connected in series between the secondary coil of the first transformer T1 and the output terminal 30 will play a role in the second half cycle of the rectangular wave.

[0048] When the waveform signal of the first half cycle of the primary coil input of the first transformer T1 ends, the input voltage is 0, that is, there is no voltage input to the primary coil of the first transformer T1. At this time, the secondary coil of the transformer immediately generates a self-induced electromotive force, and its voltage is the same as the voltage of the first half cycle, but in the opposite direction, thus forming a reverse loop and generating reverse noise. In the case that the secondary coil of the first transformer T1 is not connected in series with the first diode D1, the positive half-axis waveform output by the rectangular wave shaping circuit is as follows: Figure 3a When the secondary coil of the first transformer T1 is connected in series with the first diode D1, the reverse noise is greatly weakened under the action of the first diode D1. At this time, the positive half-axis waveform output by the rectangular wave shaping circuit is as follows: Figure 4a shown.

[0049] Further, refer to Figure 5 As shown, in a specific embodiment, the connection between the first diode D1 and the secondary coil of the first transformer T1 and the output terminal 30 can be: the anode of the first diode D1 is connected to the positive output end of the secondary coil of the first transformer T1, and the cathode of the first diode D1 is connected to the positive pole of the output terminal 30.

[0050] The two ends of the first switch K1 can be connected to the negative electrode of the output terminal 30 and the negative output end of the secondary coil of the first transformer T1 respectively. Therefore, when the first switch K1 is closed, a Figure 5 In the closed loop A of the current direction shown, the rectangular wave shaping circuit outputs a positive half-axis waveform.

[0051] It is understood that, in addition to the above connection method, the connection method between the first diode D1 and the secondary coil of the first transformer T1 and the output terminal 30 can also be: the cathode of the first diode D1 is connected to the negative output end of the secondary coil of the first transformer T1, and the anode of the first diode D1 is connected to the negative electrode of the output terminal 30.

[0052] In addition, in addition to the first diode D1, the first shaping circuit 10 can also be connected in series with an additional diode, such as Figure 5 As shown, one diode is connected in series between the positive output end of the secondary coil of the first transformer T1 and the positive electrode of the output terminal 30, and another diode is connected in series between the negative output end of the secondary coil of the first transformer T1 and the negative electrode of the output terminal 30. When the first switch K1 is closed, a closed loop is formed between the secondary coil of the first transformer T1, the two diodes, and the first switch K1, and the rectangular wave shaping circuit outputs a positive half-axis waveform.

[0053] Although the diode connected in series between the secondary winding of the first transformer T1 and the output terminal 30 significantly reduces reverse noise, a small amount of reverse voltage still occurs. This is because the diode always has a very small amount of leakage current. When reverse voltage occurs, the diode is not completely cut off, resulting in the formation of a reverse loop, and the reverse noise is not completely eliminated.

[0054] refer to Figure 5 As shown, in order to further reduce the reverse noise, based on the above embodiment, as a preferred implementation, the first shaping circuit 10 further includes:

[0055] The third diode D3; the cathode of the third diode D3 is connected to the positive output terminal of the secondary coil of the first transformer T1, and the anode of the third diode D3 is connected to the negative output terminal of the secondary coil of the first transformer T1.

[0056] At this point, the third diode D3, connected in parallel with the secondary coil of the first transformer T1, works in conjunction with the first diode D1 in series. In the second half of the cycle, although the leakage current of the first diode D1 forms a reverse loop, the third diode D3 begins to function, almost completely absorbing the self-induced electromotive force at this time. Furthermore, due to the unidirectional conduction of the diode, the third diode D3 does not interfere with the output of the positive half-axis wave in the first half of the cycle. The waveform output by the first shaping circuit 10 is as follows: Figure 6a shown.

[0057] Furthermore, a sudden loss of power to the coil generates a large self-induced electromotive force (EMF). This instantaneous voltage can break down electronic components exceeding their withstand voltage, or even exceed the withstand voltage of the coil itself, causing damage. Therefore, based on the above embodiment, as a preferred embodiment, the first shaping circuit 10 further includes a first resistor R1 connected in parallel across the secondary coil of the first transformer T1. Connecting the resistor in parallel across the coil ensures a current path during a sudden power outage, thereby reducing the rate of change of current and the self-induced EMF, thereby preventing breakdown of electronic components and damage to the coil.

[0058] The second shaping circuit 20 includes a second transformer T2, a second diode D2, and a second switch K2. The positive electrode of the output terminal 30 is connected to the negative output terminal of the secondary winding of the second transformer T2, and the negative electrode of the output terminal 30 is connected to the positive output terminal of the secondary winding of the first transformer T1. The second diode D2 and the second switch K2 are connected in series between the secondary winding of the second transformer T2 and the output terminal 30.

[0059] Similarly, when the waveform signal of the first half cycle of the primary coil input of the second transformer T2 ends, the input voltage is 0, that is, there is no voltage input to the primary coil of the second transformer T2. At this time, the secondary coil of the transformer immediately generates a self-induced electromotive force, and its voltage is the same as the voltage of the first half cycle, but in the opposite direction, thus forming a reverse loop and generating reverse noise. In the case that the secondary coil of the second transformer T2 is not connected in series with the second diode D2, the negative half-axis waveform output by the rectangular wave shaping circuit is as follows: Figure 3b When the secondary coil of the second transformer T2 is connected in series with the second diode D2, the reverse noise is greatly weakened under the action of the second diode D2. At this time, the negative half-axis waveform output by the rectangular wave shaping circuit is as follows: Figure 4b shown.

[0060] Further, refer to Figure 5 As shown, in a specific embodiment, the connection between the second diode D2 and the secondary coil of the second transformer T2 and the output terminal 30 can be: the anode of the second diode D2 is connected to the positive output end of the secondary coil of the second transformer T2, and the cathode of the second diode D2 is connected to the negative pole of the output terminal 30.

[0061] The two ends of the second switch K2 can be connected to the positive electrode of the output terminal 30 and the negative output end of the secondary coil of the second transformer T2 respectively. Therefore, when the second switch K2 is closed, a Figure 5 In the closed loop B of the current direction shown, the rectangular wave shaping circuit outputs a negative half-axis waveform.

[0062] Similarly, in addition to the above connection method, the connection method between the second diode D2 and the secondary coil of the second transformer T2 and the output terminal 30 can also be: the cathode of the second diode D2 is connected to the negative output end of the secondary coil of the second transformer T2, and the anode of the second diode D2 is connected to the positive electrode of the output terminal 30.

[0063] In addition, in addition to the second diode D2, the second shaping circuit 20 can also be connected in series with an additional diode, such as Figure 5 As shown, one diode is connected in series between the positive output end of the secondary coil of the second transformer T2 and the negative electrode of the output terminal 30, and another diode is connected in series between the negative output end of the secondary coil of the second transformer T2 and the positive electrode of the output terminal 30. When the second switch K2 is closed, a closed loop is formed between the secondary coil of the second transformer T2, the two diodes, the output terminal 30, and the second switch K2, and the rectangular wave shaping circuit outputs a negative half-axis waveform.

[0064] Further, refer to Figure 5 As shown, based on the above embodiment, as a preferred implementation, the second shaping circuit 20 further includes:

[0065] A fourth diode D4 has a cathode connected to the positive output end of the secondary coil of the second transformer T2 , and an anode connected to the negative output end of the secondary coil of the second transformer T2 .

[0066] At this time, the fourth diode D4 connected in parallel with the secondary coil of the second transformer T2 works in conjunction with the second diode D2 connected in series with the secondary coil of the second transformer T2. In the second half of the cycle, although the leakage current of the second diode D2 forms a reverse loop, the fourth diode D4 begins to work and can almost completely absorb the self-induced electromotive force at this time. Similarly, due to the unidirectional conduction effect of the diode, the fourth diode D4 does not cause interference when outputting the positive half-axis wave in the first half of the cycle. The waveform output by the rectangular wave shaping circuit is as follows: Figure 6b shown.

[0067] Furthermore, based on the above embodiment, as a preferred implementation, the second shaping circuit 20 further includes a second resistor R2 connected in parallel across the secondary coil of the second transformer T2. Connecting a resistor in parallel across the coil ensures a current path during a sudden power outage, thereby reducing the rate of change of current and the self-induced electromotive force, thereby preventing breakdown of electronic components and damage to the coil.

[0068] Furthermore, based on the above embodiment, as a preferred implementation, both the first switch K1 and the second switch K2 are solid-state relays. This allows for time-sharing coordination between the two transformers through the solid-state relays and the MCU circuit. Furthermore, solid-state relays offer long life and high speed, enabling the generation of high-frequency forward and reverse waveforms.

[0069] When the first transformer T1 has input, the solid-state relay in the first shaping circuit 10 can be controlled to close by the MCU circuit; when the second transformer T2 has input, the solid-state relay in the second shaping circuit 20 can be controlled to close by the MCU circuit; when both the first transformer T1 and the second transformer T2 have no input, the solid-state relays in the first shaping circuit 10 and the second shaping circuit 20 can be in the off state.

[0070] In summary, the rectangular wave shaping circuit provided in this application is provided with two shaping circuits, enabling the rectangular wave circuit to output both a positive and negative half-axis waveform, thereby meeting the requirements for positive and negative half-axis waveform output. Furthermore, each shaping circuit is connected in series with a diode. By leveraging the unidirectional conductivity of the diode, the reverse pulse noise caused by the self-induced electromotive force can be effectively weakened, making the rectangular wave signal purer.

[0071] The present application also provides an electrical stimulation device, which includes the rectangular wave shaping circuit described above. The present application does not elaborate on the electrical stimulation device provided by the present application, and reference is made to the embodiment of the rectangular wave shaping circuit described above.

[0072] Because the situation is complicated, it is impossible to list them one by one for explanation. Those skilled in the art should be aware that there may be multiple examples based on the basic principles of the embodiments provided in this application and in combination with actual conditions, and all of them should be within the scope of this application without sufficient creative work.

[0073] The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to in detail.

[0074] The above is a detailed introduction to the technical solution provided by the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only intended to help understand the method and core ideas of the present application. It should be pointed out that, for those skilled in the art, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

[0075] It should also be noted that, in this specification, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or device comprising the element.

Claims

1. A rectangular wave shaping circuit, characterized in that: include: a first shaping circuit, a second shaping circuit, and an output terminal; The first shaping circuit includes a first transformer, a first diode and a first switch; The output terminal is connected in parallel to both ends of the secondary coil of the first transformer, and the first diode and the first switch are connected in series between the secondary coil of the first transformer and the output terminal. When the first switch is closed, the secondary coil of the first transformer, the output terminal, the first diode, and the first switch form a closed loop, and the rectangular wave shaping circuit outputs a positive half-axis waveform. The second shaping circuit includes a second transformer, a second diode, and a second switch; the output terminal is connected in parallel to both ends of the secondary coil of the second transformer, and the second diode and the second switch are connected in series between the secondary coil of the second transformer and the output terminal. When the second switch is closed, the secondary coil of the second transformer, the output terminal, the second diode, and the second switch form a closed loop, and the rectangular wave shaping circuit outputs a negative half-axis waveform; The positive output terminal of the first shaping circuit is connected to the positive electrode of the output terminal, and the negative output terminal of the first shaping circuit is connected to the negative electrode of the output terminal; the positive output terminal of the second shaping circuit is connected to the negative electrode of the output terminal, and the negative output terminal of the second shaping circuit is connected to the positive electrode of the output terminal; An anode of the first diode is connected to the positive output end of the secondary coil of the first transformer, and a cathode of the first diode is connected to the positive electrode of the output terminal; The first shaping circuit further includes: The third diode; The cathode of the third diode is connected to the positive output end of the secondary coil of the first transformer, and the anode of the third diode is connected to the negative output end of the secondary coil of the first transformer.

2. The rectangular wave shaping circuit according to claim 1, characterized in that: The first shaping circuit further includes: A first resistor; the first resistor is connected in parallel to both ends of the secondary coil of the first transformer.

3. The rectangular wave shaping circuit according to claim 1, wherein: An anode of the second diode is connected to the positive output end of the secondary coil of the second transformer, and a cathode of the second diode is connected to the negative electrode of the output terminal.

4. The rectangular wave shaping circuit according to claim 3, characterized in that: The second shaping circuit further includes: A fourth diode, wherein a cathode of the fourth diode is connected to the positive output end of the secondary coil of the second transformer, and an anode of the fourth diode is connected to the negative output end of the secondary coil of the second transformer.

5. The rectangular wave shaping circuit according to claim 4, characterized in that: The second shaping circuit further includes: A second resistor is connected in parallel to both ends of the secondary coil of the second transformer.

6. The rectangular wave shaping circuit according to claim 1, wherein: The first switch and the second switch are both solid-state relays.

7. An electrical stimulation device, characterized in that The method comprises the rectangular wave shaping circuit according to any one of claims 1 to 6.

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