An electrotherapy boost and adjustment circuit and electrotherapy equipment

Abstract

The present invention provides an electrotherapy boost and adjustment circuit and electrotherapy equipment thereof, comprising a processor, a boost circuit, a voltage doubling circuit, and a voltage sampling circuit connected in sequence, wherein the voltage sampling circuit is also connected to the processor, wherein: the processor is used to output an enable control signal; the boost circuit is used to amplify the power supply input voltage to a first output voltage; the voltage doubling circuit is used to generate a second output voltage, which is N times the first output voltage; and the voltage sampling circuit is used to provide a feedback voltage to the boost circuit to limit the second output voltage. The electrotherapy boost and adjustment circuit and electrotherapy equipment of the present invention add a capacitor voltage doubling circuit to the boost circuit, which can achieve a higher boost ratio; the circuit is safe, and there is a maximum voltage limit inside the chip; the control is simple, and only the time of the boost chip enable pin and the feedback voltage of the processor's analog-to-digital conversion circuit need to be controlled; the entire circuit system is closed-loop controlled, and the output voltage is stable.

Description

Technical Field

[0001] The present invention belongs to the field of electrotherapy equipment in physical therapy instruments, in particular to the field of low-medium frequency therapy equipment, and relates to an electrotherapy boost and adjustment circuit and electrotherapy equipment. Background Art

[0002] Electrotherapy utilizes various types of electric current and electromagnetic fields to treat illnesses. These include direct current (DC), low-frequency pulsed electrotherapy, medium-frequency pulsed electrotherapy, and high-frequency electrotherapy. All of these electrotherapy treatments require voltage. Since human skin impedance is typically above 1 kΩ, the pulse voltage of typical electrotherapy devices is approximately 50V to 100V. Conventional button batteries (CR2032) have an output voltage of 3V. To increase this voltage to 50V to 100V or higher, a boost circuit is required. Because skin impedance varies with the environment and from person to person, the high voltage of the electrotherapy device must be adjusted to ensure consistent efficacy.

[0003] Existing electrotherapy boost circuits have problems such as limited boost ratio, low circuit safety, complex control, and unadjustable output voltage. Therefore, how to provide a boost circuit and electrotherapy equipment that can meet voltage requirements, have a safe circuit, simple control, and adjustable output voltage has become an important technical problem that needs to be urgently solved by technical personnel in this field. Summary of the Invention

[0004] In view of the shortcomings of the prior art described above, the purpose of the present invention is to provide an electrotherapy boost and adjustment circuit and electrotherapy equipment to solve the problems in the prior art of limited boost ratio, low circuit safety, complex control and unadjustable output voltage of the electrotherapy boost circuit.

[0005] To achieve the above-mentioned and other related objectives, the present invention provides an electrotherapy boost and adjustment circuit, comprising a processor, a boost circuit, a voltage multiplier circuit, and a voltage sampling circuit connected in sequence, wherein:

[0006] The processor is used to output an enable control signal to the boost circuit and obtain the feedback voltage of the voltage sampling circuit;

[0007] The boost circuit is used to amplify the power input voltage into a first output voltage;

[0008] The voltage doubling circuit is used to generate a second output voltage, where the second output voltage is N times the first output voltage, where N is an integer greater than 1;

[0009] The voltage sampling circuit is used to divide the second output voltage to output the feedback voltage.

[0010] Optionally, the boost circuit includes a boost chip, an inductor, a unidirectional boost diode, a first energy storage capacitor and a second energy storage capacitor; the boost chip includes an enable terminal, a voltage input terminal, a switch output terminal, a feedback terminal and a ground terminal; one end of the inductor is connected to the power supply input voltage and the voltage input terminal, and the other end is connected to the switch output terminal and the input terminal of the unidirectional boost diode; one end of the first energy storage capacitor is connected to the power supply input voltage, and the other end is grounded; one end of the second energy storage capacitor is connected to the output terminal of the unidirectional boost diode, and the other end is grounded; the enable terminal and the feedback terminal are connected to the processor.

[0011] Optionally, the voltage doubling circuit includes a double voltage doubling circuit.

[0012] Optionally, the voltage doubling circuit includes a first voltage doubling capacitor, a second voltage doubling capacitor, a third voltage doubling capacitor, a fourth voltage doubling capacitor, a first voltage doubling diode, a second voltage doubling diode, a third voltage doubling diode and a fourth voltage doubling diode; one end of the first voltage doubling capacitor is connected to the input end of the unidirectional boost diode, and the other end is connected to the output end of the first voltage doubling diode; one end of the second voltage doubling capacitor is connected to the output end of the first voltage doubling diode and the input end of the second voltage doubling diode, and the other end is connected to the output end of the third voltage doubling diode and the input end of the fourth voltage doubling diode; one end of the third voltage doubling capacitor is connected to the input end of the unidirectional boost diode and the input end of the first voltage doubling diode, and the other end is connected to the output end of the second voltage doubling diode and the input end of the third voltage doubling diode; one end of the fourth voltage doubling capacitor is connected to the input end of the third voltage doubling diode, and the other end is connected to the output end of the fourth voltage doubling diode.

[0013] Optionally, the voltage sampling circuit includes a first sampling resistor and a second sampling resistor; one end of the first sampling resistor is connected to the output end of the voltage multiplier circuit, and the other end is connected to the processor and grounded via the second sampling resistor.

[0014] Optionally, the electrotherapy boost and adjustment circuit further includes an output energy storage capacitor, one end of the output energy storage capacitor is connected to the output end of the voltage doubler circuit, and the other end is grounded.

[0015] Optionally, the processor includes an analog-to-digital conversion circuit, which is connected to the voltage feedback circuit to obtain the feedback voltage and convert it into a digital signal, and the analog-to-digital conversion circuit is connected to the feedback end of the boost circuit.

[0016] Optionally, the electrotherapy boost and adjustment circuit controls the second output voltage by controlling the enabling time of the boost circuit.

[0017] Optionally, when the feedback voltage reaches a preset value, the processor stops outputting the enable control signal.

[0018] The present invention also provides an electrotherapy device, which includes the electrotherapy boost and adjustment circuit as described in any one of the above items.

[0019] As described above, the electrotherapy boost and adjustment circuit and electrotherapy equipment of the present invention add a capacitor voltage multiplier circuit on the basis of the boost circuit, which can achieve a higher boost ratio; the circuit is safe, and there is a maximum voltage limit inside the chip; the control is simple, and only the time of the enable pin of the boost chip and the feedback voltage of the analog-to-digital conversion circuit of the processor need to be controlled; the entire circuit system is closed-loop controlled, and the output voltage is stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Shown is a boost circuit topology.

[0021] Figure 2 Displays charging Figure 1 Simplified circuit diagram of the .

[0022] Figure 3 Displayed as discharging Figure 1 Simplified circuit diagram of the .

[0023] Figure 4 It shows a chip-type solution of a boost circuit.

[0024] Figure 5 Shown is a boost circuit implemented with discrete components.

[0025] Figure 6a Shown as a voltage doubling circuit.

[0026] Figure 6b Display as Figure 6a Voltage waveform of AC power supply.

[0027] Figure 7 It shows a boost circuit with an additional voltage doubling circuit.

[0028] Figure 8 Shown is a principle block diagram of the electrotherapy boost and regulation circuit of the present invention.

[0029] Figure 9 Shown is an example circuit diagram of the electrotherapy boost and regulation circuit of the present invention.

[0030] Component number description

[0031] 1 processor

[0032] 2 Boost circuit

[0033] 3-fold voltage circuit

[0034] 4 Voltage sampling circuit DETAILED DESCRIPTION

[0035] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention.

[0036] See also Figures 1 to 9 It should be noted that the illustrations provided in this embodiment are only used to schematically illustrate the basic concept of the present invention. Therefore, the illustrations only show components related to the present invention and are not drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component can be changed at will, and the component layout type may also be more complicated.

[0037] The boost circuit can be realized by controlling the switch tube by pulse width modulation (PWM); a boost circuit topology is as follows Figure 1 As shown, it is mainly composed of inductor L1, switch tube Q1 and diode D1. The working process can be divided into two parts: charging and discharging. When charging, the switch tube Q1 is turned on, which can be understood as a MOS tube that is equivalent to a wire directly connecting the drain and source. Figure 1 Can be simplified to Figure 2 As shown in the circuit diagram, the input voltage flows through the inductor L1, the switch Q1, and the capacitor C1. As the charging continues, the current on the inductor increases linearly. At a certain point, the inductor stores a certain amount of energy. During this process, the diode D1 is reverse biased and cut off, and the capacitor C2 provides energy to the load to keep the load working. During the discharge process, when the switch is not conducting, the switch Q1 is equivalent to being disconnected. Figure 1 Can be simplified as Figure 3 In the circuit diagram shown, due to the reverse electromotive force of the inductor, the current in the inductor cannot change suddenly, but instead discharges slowly and gradually. Since the original circuit is disconnected, the inductor can only discharge through the circuit of diode D1, the load, and capacitor C1. This means that the inductor begins to charge capacitor C2. Since capacitor C2 already provides voltage before charging capacitor C2, the voltage across the capacitor increases. Generally, the output capacitor C2 should be large enough to ensure a continuous current at the output during discharge. At the same time, the diode is generally at least a fast recovery diode.

[0038] Figure 4The chip-type solution for a boost circuit is shown, with an output voltage Vout = Vfb*(R1+R2) / R2, where U1 is a conventional boost chip and R1 and R2 are sampling resistors. If the feedback voltage Vfb is less than the reference voltage, a PWM wave pulse width control switch is added to quickly boost the voltage through the inductor L1 and diode D1. If Vfb is greater than or equal to the reference voltage, the PWM wave is stopped. The advantages of this solution are: (1) Simple design, only need to refer to the corresponding chip manual for design, the solution is mature and stable; (2) Simple processor control, only need to control the EN pin; (3) Circuit safety, there is an overcurrent protection circuit inside the chip; (4) Wide selection, can be implemented by conventional boost chips on the market. The disadvantages of this solution are: (1) The boost ratio is limited, and can only be increased to 10 times the input voltage; (2) The voltage cannot be adjusted by the processor, and can only output a fixed voltage.

[0039] Figure 5 This is another boost circuit implemented with discrete components, where PWM is generated by the processor and FB is fed back to the processor's internal AD for sampling. The pulse width of the PWM wave is adjusted based on the feedback data from FB, ultimately achieving the purpose of boosting. The advantages of this solution are: (1) low cost, requiring only a few passive components, and the core control is implemented by the processor; (2) the output voltage is adjustable, and the PWM pulse width is adjusted based on the feedback from the FB pin, ultimately achieving the purpose of adjusting the output voltage. The disadvantages of this solution are: (1) the processor control is complex, requiring the processor to control the boost circuit; (2) there is no overcurrent protection, and the overcurrent protection of the switch tube Q1 is missing; (3) the program control safety cannot be guaranteed. If the program fails, the high-voltage output voltage cannot be guaranteed; (4) the boost ratio is limited, and can only be increased to 10 times the input voltage.

[0040] Therefore, based on the characteristics of the above two circuits, a boost circuit that can meet voltage requirements, has circuit safety, simple control, and adjustable output voltage is very necessary.

[0041] The present invention adds a DC voltage doubling circuit to a conventional boost chip to boost the power supply input voltage (e.g., a 3V battery voltage) to 50V to 100V. The output voltage is adjusted by controlling the timing of the boost chip's enable terminal EN (used to receive an enable control signal SHDN output by a processor). Feedback on the boosted voltage is obtained through the analog-to-digital conversion circuit ADC of a processor (e.g., a single-chip microcomputer).

[0042] Specifically, a voltage doubler circuit is a circuit that utilizes the energy storage of a capacitor and the unidirectional conduction characteristics of a diode to double an AC voltage to a higher voltage. Figure 6aIt is shown as a voltage doubling circuit, which can increase the input voltage to 2, 3 or even higher times of the peak voltage UI through the combination of different levels of capacitors and diodes. The advantage of this capacitor-type voltage doubling circuit is that no matter how many times the UI is finally increased, there will be no excessive surge voltage on the input power supply, so that a power supply with higher output voltage can be designed using low-voltage chips. Figure 6b Display as Figure 6a Voltage waveform of AC power supply.

[0043] If an AC source is designed, it can be connected to the charge pump for voltage doubling. Figure 3 In the circuit shown, the switch node SW is an AC source, so a voltage doubler circuit can be added to achieve a 2Vo voltage output. Figure 7 As shown, the diodes and capacitors are very common devices.

[0044] It should be noted that in the voltage doubler circuit, only capacitors are used as energy storage and filtering devices, so it is suitable for low-power power supply design.

[0045] See also Figure 8 , which shows a principle block diagram of the electrotherapy boost and adjustment circuit of the present invention, including a processor 1, a boost circuit 2, a voltage doubler circuit 3 and a voltage sampling circuit 4 connected in sequence, and the voltage sampling circuit is also connected to the processor to realize closed-loop control, wherein: the processor 1 is used to output an enable control signal to the boost circuit 2 and obtain the feedback voltage of the voltage sampling circuit 4; the boost circuit 2 is used to amplify the power supply input voltage into a first output voltage; the voltage doubler circuit is used to generate a second output voltage, which is N times the first output voltage, and N is an integer greater than 1; the voltage sampling circuit 4 is used to divide the second output voltage to output the feedback voltage.

[0046] Specifically, the electrotherapy boost and adjustment circuit of the present invention adds a voltage multiplication circuit to a conventional boost circuit. The circuit's maximum output voltage is controlled by the feedback voltage-dividing resistor of the voltage sampling circuit. After voltage division by the resistors, the current output voltage (i.e., feedback voltage) is applied to the processor's analog-to-digital converter (ADC). The processor controls the enable (SHDN) time of the boost chip to control the circuit's current output voltage. When the output voltage meets the requirement, the boost chip is disabled. The present invention also adds a high-voltage energy storage circuit to prepare for high-voltage pulse output.

[0047] As an example, see Figure 9, shows an example circuit diagram of the electrotherapy boost and adjustment circuit of the present invention, wherein the boost circuit includes a boost chip U1, an inductor L1, a unidirectional boost diode D1, a first energy storage capacitor C2 and a second energy storage capacitor C4; the boost chip U1 includes an enable terminal EN, a voltage input terminal VIN, a switch output terminal SW, a feedback terminal FB and a ground terminal GND; one end of the inductor L1 is connected to the power supply input voltage Vin and the voltage input terminal VIN, and the other end is connected to the switch output terminal SW and the input end of the unidirectional boost diode D1; one end of the first energy storage capacitor C2 is connected to the power supply input voltage Vin, and the other end is grounded; one end of the second energy storage capacitor C4 is connected to the output end of the unidirectional boost diode D1, and the other end is grounded; the enable terminal EN and the feedback terminal FB are connected to the processor ( Figure 9 (not shown in the figure).

[0048] As an example, the boost chip U1 may be a conventional integrated boost chip or other suitable chip.

[0049] As an example, Figure 9 As shown, the voltage doubling circuit is used to perform 2-times voltage based on the boost chip U1, including a first voltage doubling capacitor C1, a second voltage doubling capacitor C3, a first voltage doubling diode D2 and a second voltage doubling diode D3, wherein one end of the first voltage doubling capacitor C1 is connected to the input end of the unidirectional boost diode D1, and the other end is connected to the output end of the first voltage doubling diode D2; one end of the second voltage doubling capacitor C3 is connected to the output end of the unidirectional boost diode D1 and the input end of the first voltage doubling diode D2, and the other end is connected to the output end of the second voltage doubling diode D3.

[0050] As an example, Figure 9 As shown, the voltage sampling circuit includes a first sampling resistor R1 and a second sampling resistor R2. One end of the first sampling resistor R1 is connected to the output end of the voltage multiplier circuit, and the other end is connected to the processor and grounded via the second sampling resistor R2. The first sampling resistor R1 and the second sampling resistor R2 serve as voltage limiting resistors for the second output voltage Vout, performing a voltage divider function, where Vout = Vfb*(R1+R2) / R2.

[0051] It should be noted that in other embodiments, the electrotherapy boost and adjustment circuit can use a higher multiple voltage multiplication circuit as needed, instead of Figure 9 The voltage doubler circuit shown in is limited.

[0052] As an example, Figure 9As shown, the electrotherapy boost and adjustment circuit also includes an output energy storage capacitor C5 for storing electricity for outputting high-voltage pulses. One end of the output energy storage capacitor C5 is connected to the output end of the voltage doubler circuit, and the other end is grounded.

[0053] As an example, the processor includes an analog-to-digital conversion circuit, which is connected to the voltage feedback circuit to obtain the feedback voltage Vfb and convert it into a digital signal, and the analog-to-digital conversion circuit is connected to the feedback terminal FB of the boost circuit.

[0054] As an example, the electrotherapy boost and adjustment circuit controls the feedback voltage Vfb by controlling the enable time of the boost circuit, thereby controlling the second output voltage Vout, wherein when the feedback voltage Vfb reaches a preset value, the processor stops outputting the enable control signal.

[0055] As an example, the present invention also provides an electrotherapy device, which includes the electrotherapy boost and adjustment circuit as described above, and can be used for electromyography stimulation. The high voltage of the electrotherapy device can be adjusted to ensure that the electrotherapy device has consistent effects in different environments or for skin with different impedances.

[0056] In summary, the electrotherapy boost and adjustment circuit and electrotherapy device of the present invention utilizes a capacitor voltage multiplier circuit in addition to a boost circuit, achieving a high boost ratio. The circuit is safe, with a maximum voltage limit internal to the chip. Control is simple, requiring only the timing of the boost chip's enable pin and the feedback voltage from the processor's analog-to-digital conversion circuit. The entire circuit system utilizes closed-loop control, resulting in a stable output voltage. Therefore, the present invention effectively overcomes the shortcomings of the prior art and possesses high industrial value.

[0057] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. An electrotherapy boost and adjustment circuit, characterized in that: It includes a processor, a boost circuit, a voltage doubling circuit and a voltage sampling circuit connected in sequence, wherein the voltage sampling circuit is also connected to the processor, wherein: The processor is used to output an enable control signal to the boost circuit and obtain the feedback voltage of the voltage sampling circuit; The boost circuit is used to amplify the power input voltage into a first output voltage; The voltage doubling circuit is used to generate a second output voltage, where the second output voltage is N times the first output voltage, where N is an integer greater than 1; The voltage sampling circuit is used to divide the second output voltage to output the feedback voltage; Wherein, the boost circuit includes a boost chip, an inductor, a unidirectional boost diode, a first energy storage capacitor and a second energy storage capacitor; the boost chip includes an enable terminal, a voltage input terminal, a switch output terminal, a feedback terminal and a ground terminal; one end of the inductor is connected to the power supply input voltage and the voltage input terminal, and the other end is connected to the switch output terminal and the input terminal of the unidirectional boost diode; one end of the first energy storage capacitor is connected to the power supply input voltage, and the other end is grounded; one end of the second energy storage capacitor is connected to the output terminal of the unidirectional boost diode, and the other end is grounded; the enable terminal and the feedback terminal are connected to the processor; The processor includes an analog-to-digital conversion circuit, which is connected to the voltage sampling circuit to obtain the feedback voltage and convert it into a digital signal, and the analog-to-digital conversion circuit is connected to the feedback end of the boost circuit; The processor controls the second output voltage by controlling the enabling time of the boost circuit; When the feedback voltage reaches a preset value, the processor stops outputting the enable control signal.

2. The electrotherapy boost and regulation circuit according to claim 1, characterized in that: The voltage doubling circuit includes a double voltage doubling circuit.

3. The electrotherapy boost and regulation circuit according to claim 2, characterized in that: The voltage doubling circuit includes a first voltage doubling capacitor, a second voltage doubling capacitor, a first voltage doubling diode and a second voltage doubling diode; one end of the first voltage doubling capacitor is connected to the input end of the unidirectional boost diode, and the other end is connected to the output end of the first voltage doubling diode; one end of the second voltage doubling capacitor is connected to the output end of the unidirectional boost diode and the input end of the first voltage doubling diode, and the other end is connected to the output end of the second voltage doubling diode.

4. The electrotherapy boost and regulation circuit according to claim 1, wherein: The voltage sampling circuit includes a first sampling resistor and a second sampling resistor; one end of the first sampling resistor is connected to the output end of the voltage multiplier circuit, and the other end is connected to the processor and grounded via the second sampling resistor.

5. The electrotherapy boost and regulation circuit according to claim 1, wherein: The electrotherapy boost and adjustment circuit further includes an output end energy storage capacitor, one end of the output end energy storage capacitor is connected to the output end of the voltage doubler circuit, and the other end is grounded.

6. An electrotherapy device, characterized in that: The electrotherapy device includes the electrotherapy boost and adjustment circuit as described in any one of claims 1-5.

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