CN214799300U

CN214799300U - Microprocessor controlled PWM high voltage generator

Info

Publication number: CN214799300U
Application number: CN202021929499.1U
Authority: CN
Inventors: 崔坤新; 徐慧伟
Original assignee: Wuxi Longxin Mechanical And Electrical Engineering Co ltd
Current assignee: Wuxi Longxin Mechanical And Electrical Engineering Co ltd
Priority date: 2020-09-07
Filing date: 2020-09-07
Publication date: 2021-11-19
Anticipated expiration: 2030-09-07

Abstract

The utility model discloses a microprocessor control's PWM high pressure generator, this high pressure generator have microprocessor unit, network communication unit, POE power supply unit, drive circuit, boost rectifier circuit, voltage negative feedback circuit and system power supply unit to constitute, microprocessor unit comprises STM32F103C8T6 treater, and operation ucos-ii real-time operating system, microprocessor passes through the SPI bus and is connected with communication chip, receives the order that upper control system issued. The microprocessor-controlled PWM high-voltage generator is provided with a 100M network communication port, and measurement and control software can control the high-voltage generator through a network. This generator still provides the POE function, both can supply power through outside independent power source, also can get the electric mode through the net twine and supply power for the system, and the high voltage generator who adopts microprocessor control has that output voltage is stable, output voltage continuous variation, closed loop negative feedback control, can provide network interface, RS232 or RS485 mode's communication interface, conveniently inserts the system of observing and controling.

Description

Microprocessor controlled PWM high voltage generator

Technical Field

The utility model relates to a PWM high pressure generator technical field specifically is microprocessor control's PWM high pressure generator.

Background

The microprocessor outputs PWM (pulse width modulation waveform) to control the power switch tube, and after boosting and rectifying by the booster coil, direct current high voltage is generated, and the high voltage range is 500-3 KV. The output high voltage is fed back to the microprocessor AD input to form a negative feedback loop, so that accurate high voltage output is realized. Because of the microprocessor control, the output high voltage can be continuously changed and can be output in a grading way. Under the step output mode, when the output voltage is switched to the gear, the output voltage is continuously changed until the specified voltage is reached, so that the impact of direct voltage switching on a high-voltage output circuit is avoided.

Conventional high voltage generators typically use a fixed oscillator circuit to generate the ac waveform, or a fixed circuit to generate the PWM waveform, which is then passed through a boost coil to generate the high voltage. The two modes have more components, fixed voltage output and large switching jitter, and the adopted components have more components and large volume. Because the common high-voltage generator does not have the remote control function, the application of the common high-voltage generator in the fields of automatic testing and the like is limited.

For this purpose, microprocessor-controlled PWM high-voltage generators are proposed.

SUMMERY OF THE UTILITY MODEL

The utility model provides a following technical scheme: the PWM high-voltage generator is controlled by a microprocessor and comprises a microprocessor unit, a network communication unit, a POE power supply unit, a driving circuit, a boosting and rectifying circuit, a voltage negative feedback circuit and a system power supply unit, wherein the microprocessor unit consists of an STM32F103C8T6 processor, runs a ucos-ii real-time operating system, and is connected with a communication chip through an SPI bus to receive a command issued by an upper control system;

the network communication unit is formed by a W5500 chip, a TCP/IP protocol is built in the network communication unit, the network speed is 100M, and the network chip is communicated with the microprocessor through an SPI bus;

the POE power supply unit is composed of a TPS23753 chip, and is used for reducing the voltage of a 48V power supply transmitted along with a network cable into 24V, and the voltage is stabilized to 12V by an LM2596S switch voltage reduction circuit and then is used by a booster circuit;

the driving circuit consists of a driving stage circuit and an MOSFET power switch circuit, wherein the driving stage circuit receives and amplifies a PWM signal from the microprocessor and then pushes the MOSFET power switch;

the voltage negative feedback circuit consists of a PC817 optocoupler and a TL471 reference power supply, and direct-current high voltage is divided by a resistor and then is isolated by the PC817 to be sent to an AD conversion pin of the microprocessor;

the system power supply unit reduces the voltage of a 12V power supply generated by the POE power supply unit to 3.3V power supply through the switch voltage reduction circuit, and the power supply unit is used by the microprocessor system.

Preferably, the microprocessor unit generates a PWM waveform by configuring an internal PWM parameter, a chip of the microprocessor unit is built in with a 12-bit AD converter, wherein a channel 0 is connected to a voltage negative feedback circuit, and the internal program adjusts the PWM parameter according to a comparison between a detected actual output voltage value and a set value, so as to reduce an output voltage error to an allowable range.

Preferably, after the pin 5 of the TPS23753 chip is placed at a non-0 level by an external switch, an output voltage is 0 v, and the system does not have a high voltage output.

Preferably, the step-up transformer has a transformation ratio of 1: 600, preparing a mixture; the MOSFET power switch drives the primary coil of the step-up transformer, and the secondary side of the step-up transformer generates induced alternating voltage which is converted into direct current high voltage after full-bridge rectification and filtering.

Preferably, after the microprocessor unit is subjected to AD sampling, the microprocessor unit is compared with a set voltage value, the pulse width of the PWM is adjusted according to the error magnitude, and the output voltage is changed until the error approaches to 0.

Compared with the prior art, the utility model provides a microprocessor control's PWM high voltage generator possesses following beneficial effect: the generator is provided with a 100M network communication port, and the measurement and control software can control the high-voltage generator through a network. This generator still provides the POE function, both can supply power through outside independent power source, also can get the electric mode through the net twine and supply power for the system, and the high voltage generator who adopts microprocessor control has that output voltage is stable, output voltage continuous variation, closed loop negative feedback control, can provide network interface, RS232 or RS485 mode's communication interface, conveniently inserts the system of observing and controling.

Drawings

FIG. 1 is a circuit diagram of a microprocessor unit according to the present invention;

fig. 2 is a circuit diagram of the network interface of the present invention;

fig. 3 is a circuit diagram of the POE power supply of the present invention;

fig. 4 is a circuit diagram of the high voltage generating circuit of the present invention;

fig. 5 is a circuit diagram of the voltage feedback circuit of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

As shown in fig. 1-5, the microprocessor-controlled PWM high-voltage generator includes a microprocessor unit, a network communication unit, a POE power supply unit, a driving circuit, a boost rectifier circuit, a voltage negative feedback circuit, and a system power supply unit, where the microprocessor unit includes an STM32F103C8T6 processor, runs a ucos-ii real-time operating system, and is connected to a communication chip via an SPI bus to receive a command issued by an upper control system;

The microprocessor unit generates PWM waveform by configuring internal PWM parameters, a chip of the microprocessor unit is internally provided with a 12-bit AD converter, a channel 0 is connected with a voltage negative feedback circuit, and the internal program adjusts the PWM parameters according to comparison between a detected actual output voltage value and a set value, so that the error of the output voltage is reduced to an allowable range.

After the 5 th pin of the TPS23753 chip is placed at a non-0 level by an external switch, the output voltage is 0V, and the system has no high-voltage output.

The transformation ratio of the step-up transformer is 1: 600, preparing a mixture; the MOSFET power switch drives the primary coil of the step-up transformer, and the secondary side of the step-up transformer generates induced alternating voltage which is converted into direct current high voltage after full-bridge rectification and filtering.

After AD sampling, the microprocessor unit compares the voltage value with a set voltage value, adjusts the pulse width of PWM according to the error magnitude, and changes the output voltage until the error tends to 0.

The high voltage generator is composed of a microprocessor unit, a network communication unit, a POE power supply unit, a driving circuit, a boosting and rectifying circuit, a voltage negative feedback power supply unit and a system power supply unit;

the microprocessing unit consists of an STM32F103C8T6 processor, runs a ucos-ii real-time operating system, and generates PWM waveforms by configuring internal PWM parameters; a chip of the microprocessor unit is internally provided with a 12-bit AD converter, wherein a channel 0 is connected with a voltage negative feedback circuit, and an internal program adjusts PWM parameters according to comparison between a detected actual output voltage value and a set value so as to reduce the error of the output voltage to an allowable range; the micro-processor is connected with the communication chip through the SPI bus and receives a command issued by the upper control system; the circuit is shown in FIG. 1;

the network communication unit is formed by a W5500 chip, a TCP/IP protocol is built in, the network speed is 100M, and the network chip is communicated with the microprocessor through an SPI bus, as shown in figure 2;

the POE power supply unit is composed of a TPS23753 chip, a 48V power supply which is transmitted along with a network cable is reduced to 24V, the 24V power supply is stabilized to 12V through an LM2596S switch voltage reduction circuit and then is used by a voltage boost circuit, the circuit has a manual high-voltage output control function, when the 5 th pin of LM2596S is placed at a non-0 level by an external switch, the output voltage is 0V, and the system has no high-voltage output, as shown in figure 3;

the transformation ratio of the step-up transformer is 1: 600, preparing a mixture; the mosfet power switch drives the primary coil of the step-up transformer, generates an induced ac voltage on the secondary side of the step-up transformer, and converts the induced ac voltage into a dc high voltage after full-bridge rectification and filtering, as shown in fig. 4;

the voltage negative feedback circuit consists of a PC817 optocoupler and a TL471 reference power supply, and the direct-current high voltage is divided by a resistor and then is isolated by the PC817 to be sent to an AD conversion pin of the microprocessor; after AD sampling, the microprocessor compares the voltage value with a set voltage value, adjusts the pulse width of PWM according to the error magnitude, and changes the output voltage until the error approaches to 0;

the system power supply unit reduces the voltage of a 12V power supply generated by the POE power supply unit to 3.3V through the switch voltage reduction circuit, and the power supply unit is used by the microprocessor system.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. PWM high voltage generator of microprocessor control, its characterized in that: the high-voltage generator comprises a microprocessor unit, a network communication unit, a POE power supply unit, a driving circuit, a boosting rectification circuit, a voltage negative feedback circuit and a system power supply unit, wherein the microprocessor unit consists of an STM32F103C8T6 processor, runs a ucos-ii real-time operating system, is connected with a communication chip through an SPI bus, and receives a command issued by an upper control system;

2. The microprocessor controlled PWM high voltage generator according to claim 1, wherein: the microprocessor unit generates PWM waveforms by configuring internal PWM parameters, a chip of the microprocessor unit is internally provided with a 12-bit AD converter, a channel 0 is connected with a voltage negative feedback circuit, and the internal program adjusts the PWM parameters according to comparison between a detected actual output voltage value and a set value, so that the error of the output voltage is reduced to an allowable range.

3. The microprocessor controlled PWM high voltage generator according to claim 1, wherein: after the 5 th pin of the TPS23753 chip is placed at a non-0 level by an external switch, the output voltage is 0V, and the system has no high-voltage output.

4. The microprocessor controlled PWM high voltage generator according to claim 1, wherein: the transformation ratio of the step-up transformer is 1: 600, preparing a mixture; the MOSFET power switch drives the primary coil of the step-up transformer, and the secondary side of the step-up transformer generates induced alternating voltage which is converted into direct current high voltage after full-bridge rectification and filtering.

5. The microprocessor controlled PWM high voltage generator according to claim 1, wherein: after AD sampling, the microprocessor unit compares the voltage value with a set voltage value, adjusts the pulse width of PWM according to the error magnitude, and changes the output voltage until the error tends to 0.