System for realizing isolated modulation circuit

Abstract

The utility model relates to the technical field of modulation circuits, in particular to a system for realizing an isolated modulation circuit, which comprises an M1 power supply circuit for providing voltage required by the circuit; the M2 microcontroller unit MCU is used for controlling the whole circuit; the M3 digital-to-analog conversion circuit can be realized through a DAC (Digital-to-Analog Converter) or a PWM (Pulse-Width Modulation) integral or a resistance network, and converts digital signals into analog signals for realizing signal waves; the M4 amplification / comparison circuit is used for further amplifying the signal; the M5 current control circuit is used for realizing signal separation of the VCC power supply circuit and the VDD power supply circuit; the M6 current sampling and feedback circuit is used for realizing current sampling and feeding back a signal to the M4 to form a closed-loop circuit; the M7 driving circuit is used for realizing various carrier signals; an M8 transformer performs isolation and amplification to realize isolation and power amplification of the modulated waveform; according to the utility model, the functions of simple waveform correction and dummy load are completed, no-load output of the transformer is prevented from generating over-high voltage, the isolation of the circuit is improved, the safety is high, and the control is stable.

Description

Technical Field

[0001] The utility model relates to the technical field of modulation circuits, in particular to a system for realizing an isolated modulation circuit. Background Art

[0002] There are generally two uses in AM modulation circuits. One is signal modulation, which is used for communication; the other is waveform modulation, which amplifies power and is used for energy transmission, such as medium-frequency and low-frequency physiotherapy devices. In waveform modulation applications, a signal generator is often used to couple with an oscillation circuit and drive power amplification. This method belongs to open-loop control. When the load changes, the output current follows the load change, and constant current output cannot be achieved. The current signal is not stable enough. If a class AB amplifier is used to drive the output, the efficiency is low and the heat is high. Utility Model Content

[0003] The purpose of the utility model is to provide a system for realizing an isolated modulation circuit to solve the problems raised in the above background technology.

[0004] To achieve the above-mentioned purpose, the utility model provides the following technical solution: a system for realizing an isolated modulation circuit, comprising:

[0005] M1 power supply circuit, providing the voltage required by the circuit;

[0006] M2 microcontroller unit MCU, used for the control of the entire circuit;

[0007] M3 digital-to-analog conversion circuit can be realized through DAC or PWM integration or resistor network to convert digital signals into analog signals for the realization of signal waves;

[0008] M4 amplifier / comparison circuit further amplifies the signal;

[0009] M5 current control circuit realizes signal separation of VCC and VDD power supply circuits;

[0010] M6 current sampling and feedback circuit realizes current sampling and feeds back the signal to M4 to form a closed loop circuit;

[0011] M7 driving circuit, used to realize various carrier signals;

[0012] M8 transformer isolation and amplification to achieve isolation and power amplification of the modulated waveform;

[0013] The M9 RC network and output complete the simple waveform correction and dummy load function to prevent the transformer from generating excessively high voltage at no-load output.

[0014] Preferably, the M2 microcontroller unit MCU is used to implement the control of the M3 digital-to-analog conversion and the control of the M7 drive circuit.

[0015] Preferably, the independence of the signal wave and the carrier wave is achieved by controlling the M3 digital-to-analog conversion circuit and the M7 driving circuit, and different applications can be achieved by changing the waveform of M3 and the frequency or duty cycle of M7.

[0016] Preferably, the M3 digital-to-analog conversion circuit is implemented through a DAC or PWM integration or a resistor network to convert digital signals into analog signals for the realization of signal waves.

[0017] Preferably, the M4 amplification / comparison circuit drives the M5 current control circuit and adjusts the driving signal size in real time through the M6 ​​current sampling and feedback circuit to control the current stability of the M5 current control circuit.

[0018] Preferably, the M5 current control circuit adopts a two-stage circuit to realize signal separation of the VCC and VDD power supply circuits. The first-stage power driving tube adopts a P tube, such as PNP or PMOS, to form a constant current control circuit with the control tube; the second-stage control tube generally adopts an N tube, such as an NPN tube or an NMOS tube, and is connected to a sampling resistor and a feedback circuit to the M4 amplification / comparison circuit, so that the M4 amplification / comparison circuit, the M5 current control circuit, and the M6 ​​current sampling and feedback circuit constitute signal amplification, driving and constant current control.

[0019] Compared with the prior art, the beneficial effects of the utility model are:

[0020] The circuit is simple to implement and easy to make;

[0021] Isolate the modulation circuit from the output circuit to improve safety;

[0022] The isolation design facilitates the amplification of the output waveform and achieves power boost;

[0023] Can realize constant current control and keep the output current stable;

[0024] Solve the oscillation problem caused by constant current control directly driving the isolation transformer. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the utility model. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0027] See also Figure 1 , the utility model provides a technical solution:

[0028] A system for implementing an isolated modulation circuit, comprising:

[0029] M1 power supply circuit, providing the voltage required by the circuit;

[0030] The M2 microcontroller unit MCU is used to control the entire circuit; the M2 microcontroller unit MCU is used to realize the control of the M3 digital-to-analog conversion and the M7 drive circuit. By controlling the M3 digital-to-analog conversion circuit and the M7 drive circuit, the signal wave and the carrier wave are independent. By changing the waveform of M3 and the frequency or duty cycle of M7, different applications can be realized, such as low-frequency physical therapy equipment or medium-frequency physical therapy equipment.

[0031] The M3 digital-to-analog conversion circuit can be realized through DAC or PWM integration or resistor network, which converts digital signals into analog signals for the realization of signal waves; such as generating triangle waves, sine waves, rectangular waves, etc. The output amplitude of M9 can be controlled by adjusting the output signal amplitude of M3. In the application of multi-channel modulation circuits, in order to facilitate the adjustment of the amplitude of the output part M9 waveform, a digital potentiometer or analog potentiometer is generally added in series between M3 and M4. It can also be realized by using multi-channel DAC.

[0032] The M4 amplifier / comparison circuit further amplifies the signal; the signal wave generated by the M3 digital-to-analog conversion circuit generally has weak driving and load-carrying capabilities, and needs to further improve the signal capabilities, so it is necessary to further amplify the signal through the M4 amplifier / comparison circuit. At the same time, the M4 amplifier / comparison circuit drives the M5 current control circuit and adjusts the drive signal size in real time through the M6 ​​current sampling and feedback circuit to control the current stability of the M5 current control circuit.

[0033] The M5 current control circuit realizes the signal separation of the VCC and VDD power supply circuits; the M5 current control circuit adopts a two-stage circuit to realize the signal separation of the VCC and VDD power supply circuits. The first-stage power driving tube adopts a P tube, such as PNP or PMOS, and forms a constant current control circuit with the control tube; the second-stage control tube generally adopts an N tube, such as an NPN tube or an NMOS tube, and is connected to the M4 amplification / comparison circuit with a sampling resistor and a feedback circuit. In this way, the M4 amplification / comparison circuit, the M5 current control circuit, and the M6 ​​current sampling and feedback circuit constitute signal amplification, driving and constant current control.

[0034] M6 current sampling and feedback circuit, realizes current sampling and feeds back the signal to M4 to form a closed loop circuit; belongs to the sampling circuit and feedback circuit of N tube in M5 current control circuit, realizes current sampling and feeds back the signal to M4 amplification / comparison circuit to form a closed loop circuit

[0035] The M7 drive circuit, or carrier control circuit, is used to implement various carrier signals, such as pulse waves and sine waves. It mostly uses N tubes as drive controls, such as NPN tubes, NMOS tubes, etc. Different types of modulation can be used by changing the frequency or duty cycle of the carrier.

[0036] The M8 transformer isolates and amplifies the modulated waveform to achieve isolation and power amplification; it can play a good role in safety protection in some application fields with high safety requirements.

[0037] The M9 RC network and output complete the simple correction of the waveform and the function of dummy load to prevent the transformer's no-load output from generating excessive voltage. The M9 RC network and output are electrically connected to the M8 transformer secondary output. The RC network completes the simple correction of the waveform and the function of dummy load to prevent the transformer's no-load output from generating excessive voltage.

[0038] This system can be applied to AM modulation circuits, isolated pulse modulation circuits, sinusoidal wave modulation circuits, constant current control modulation circuits, etc.

[0039] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A system for implementing an isolated modulation circuit, characterized in that: include: M1 power supply circuit, providing the voltage required by the circuit; M2 microcontroller unit MCU, used for the control of the entire circuit; M3 digital-to-analog conversion circuit can be realized through DAC or PWM integration or resistor network to convert digital signals into analog signals for the realization of signal waves; M4 amplifier / comparison circuit further amplifies the signal; M5 current control circuit realizes signal separation of VCC and VDD power supply circuits; M6 current sampling and feedback circuit realizes current sampling and feeds back the signal to M4 to form a closed loop circuit; M7 driving circuit, used to realize various carrier signals; M8 transformer isolation and amplification to achieve isolation and power amplification of the modulated waveform; The M9 RC network and output complete the simple waveform correction and dummy load function to prevent the transformer from generating excessively high voltage at no-load output.

2. A system for implementing an isolated modulation circuit according to claim 1, characterized in that: The M2 microcontroller unit MCU is used to control the M3 digital-to-analog conversion and the M7 drive circuit.

3. The system for implementing an isolated modulation circuit according to claim 2, characterized in that: The independence of the signal wave and the carrier wave is achieved by controlling the M3 digital-to-analog conversion circuit and the M7 driving circuit. Different applications can be achieved by changing the waveform of M3 and the frequency or duty cycle of M7.

4. The system for implementing an isolated modulation circuit according to claim 3, characterized in that: The M3 digital-to-analog conversion circuit is implemented through a DAC or PWM integration or a resistor network to convert a digital signal into an analog signal for the realization of a signal wave.

5. The system for implementing an isolated modulation circuit according to claim 4, characterized in that: The M4 amplification / comparison circuit drives the M5 current control circuit and adjusts the driving signal size in real time through the M6 ​​current sampling and feedback circuit to control the current stability of the M5 current control circuit.

6. The system for implementing an isolated modulation circuit according to claim 5, characterized in that: The M5 current control circuit adopts a two-stage circuit to realize signal separation of the VCC and VDD power supply circuits. The first-stage power driving tube adopts a P tube, which is a PNP or PMOS, and forms a constant current control circuit with the control tube; the second-stage control tube generally adopts an N tube, which is an NPN tube or an NMOS tube, and is connected to the M4 amplification / comparison circuit with a sampling resistor and a feedback circuit. In this way, the M4 amplification / comparison circuit, the M5 current control circuit, and the M6 ​​current sampling and feedback circuit constitute signal amplification, driving and constant current control.

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