A current and voltage sampling and display system for high-power and high-voltage power supply

Abstract

The invention discloses a current and voltage sampling and display system for a high-power high-voltage power supply, comprising an EMC module circuit, a 120V / 220V compatible circuit, a bridge rectifier circuit, a MOS tube drive circuit, a drive transformer circuit, a power management IC circuit, a power supply circuit, a constant voltage and current limiting double closed-loop circuit, a step-up transformer and a voltage doubling rectifier circuit, a voltage and current sampling circuit, a single-chip microcomputer circuit, a voltage and current AD conversion and display circuit and a status indication circuit. By adopting the invention, the high-voltage power supply itself can complete the monitoring of voltage and current and display them, and the user can understand the operation status of the equipment in real time, and make adjustments and maintenance in time, thereby improving the utilization efficiency and safety of the equipment.

Description

Technical Field

[0001] The present invention relates to the field of electrical technology, in particular to a current and voltage sampling and display system for a high-power and high-voltage power supply. Background Art

[0002] High-power, dual-loop current and voltage control in electrostatic range hood air purifiers optimizes efficiency. Users can choose between constant current and voltage-limited or constant voltage and current-limited operating modes. However, the actual operating environment and climate are constantly changing. Temperature and humidity fluctuate significantly between seasons. As the purifier ages, the accumulated grease and dirt in the electrostatic precipitator increases. These factors can cause the high-voltage power supply to operate in a state of constantly fluctuating current or voltage. This necessitates real-time monitoring of the purification system's operating conditions to facilitate timely adjustment of operating parameters or cleaning of the ion chamber. Traditionally, users, if able, measure the power supply's output voltage and current periodically using a high-voltage attenuation probe in conjunction with a voltmeter and ammeter. Based on these measurements, the current and voltage settings can be adjusted or the ion chamber can be cleaned in advance. Users without such monitoring capabilities often wait for the power supply to issue a cleaning or fault alarm before taking action, resulting in low system efficiency. If the high-voltage power supply could display the high-voltage output and load current in real time, users would be able to easily understand the purification system's operating conditions, prepare contingency plans, and ensure efficient and stable system operation. The high-voltage power supply output for range hoods typically ranges from 8kV to 12kV, with a load current of up to 10mA. If arcing or sparking occurs, the current can be even higher. Such high voltages and high arcing intensity require a microcontroller to sample and display current and voltage, placing extremely high demands on the reliability of the sampling circuit. Current sampling, in particular, is subject to higher technical requirements due to its high volatility. Existing products can only monitor a single voltage at best, and the error between the sampled display and the actual value is significant. Voltage display accuracy on commercially available products is limited to less than 90%. For a rated voltage of 12kV, the actual error can be as high as 1kV. This high error negates the significance of detection and prevents customers from accurately assessing the equipment's operating conditions. Measures are needed to prevent high voltage breakdown in CMOS chips, such as microcontrollers, and static interference in the sampled values. Summary of the Invention

[0003] The object of the present invention is to provide a current and voltage sampling and display system for a high-power and high-voltage power supply to solve the problems raised in the above background technology.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] A current and voltage sampling and display system for a high-power, high-voltage power supply comprises an EMC module circuit, a 120V / 220V compatible circuit, a bridge rectifier circuit, a MOS tube drive circuit, a drive transformer circuit, a power management IC circuit, a power supply circuit, a constant-voltage and current-limiting dual closed-loop circuit, a boost transformer and a voltage-doubling rectifier circuit, a voltage and current sampling circuit, a single-chip microcomputer circuit, a voltage and current AD conversion and display circuit, and a status indication circuit. The EMC module circuit is connected to the bridge rectifier circuit via the 120V / 220V compatible circuit, the power supply circuit is connected to the power management IC circuit, the power management IC circuit is further connected to the MOS tube drive circuit via the drive transformer circuit, the MOS tube drive circuit is further connected to the boost transformer and the voltage-doubling rectifier circuit, the bridge rectifier circuit is further connected to the MOS tube drive circuit, the voltage and current sampling circuit is respectively connected to the boost transformer and the voltage-doubling rectifier circuit, the constant-voltage and current-limiting dual closed-loop circuit, and the single-chip microcomputer circuit, the single-chip microcomputer circuit is further respectively connected to the voltage and current AD conversion and display circuit and the status indication circuit, and the constant-voltage and current-limiting dual closed-loop circuit is further connected to the power management IC circuit.

[0006] As a further technical solution of the present invention: the power supply circuit is a positive and negative 12V power supply circuit.

[0007] As a further technical solution of the present invention: the boost transformer and the voltage-doubling rectifier circuit output a positive high voltage of 8 to 12 kV and a low voltage of 4 to 6 kV.

[0008] As a further technical solution of the present invention: the status indication circuit is a 4-digit digital display screen.

[0009] As a further technical solution of the present invention: the single chip microcomputer circuit is also connected to a 485 circuit.

[0010] As a further technical solution of the present invention: the status indication circuit uses an LED driver IC GS1928 to drive a 4-digit digital display screen to display the output high voltage and load current in turn.

[0011] As a further technical solution of the present invention: the single-chip microcomputer circuit adopts AT89 series single-chip microcomputer.

[0012] Compared with the existing technology, the beneficial effect of the present invention is that: by adopting the present invention, the high-voltage power supply itself can monitor and display the voltage and current, the user can understand the operation status of the equipment in real time, and make timely adjustments and maintenance, thereby improving the utilization efficiency and safety of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is an overall block diagram of the present invention;

[0014] Figure 2 This is the schematic diagram of the voltage and current sampling circuit of a high-power high-voltage power supply;

[0015] Figure 3 This is the schematic diagram of the high-power high-voltage power supply voltage and current AD conversion circuit;

[0016] Figure 4 It is a schematic diagram of a high-power, high-voltage power supply voltage and current display circuit. DETAILED DESCRIPTION

[0017] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0018] Example 1: Please refer to Figure 1-4 A current and voltage sampling and display system for a high-power, high-voltage power supply includes an EMC module circuit, a 120V / 220V compatible circuit, a bridge rectifier circuit, a MOS tube drive circuit, a drive transformer circuit, a power management IC circuit, a power supply circuit, a constant-voltage and current-limiting dual closed-loop circuit, a boost transformer and a voltage-doubling rectifier circuit, a voltage and current sampling circuit, a single-chip microcomputer circuit, a voltage and current AD conversion and display circuit, and a status indication circuit. The EMC module circuit is connected to the bridge rectifier circuit via the 120V / 220V compatible circuit, the power supply circuit is connected to the power management IC circuit, the power management IC circuit is further connected to the MOS tube drive circuit via the drive transformer circuit, the MOS tube drive circuit is further connected to the boost transformer and the voltage-doubling rectifier circuit, the bridge rectifier circuit is further connected to the MOS tube drive circuit, the voltage and current sampling circuit is respectively connected to the boost transformer and the voltage-doubling rectifier circuit, the constant-voltage and current-limiting dual closed-loop circuit, and the single-chip microcomputer circuit, the single-chip microcomputer circuit is further respectively connected to the voltage and current AD conversion and display circuit and the status indication circuit, and the constant-voltage and current-limiting dual closed-loop circuit is further connected to the power management IC circuit.

[0019] The power supply circuit is a 12V positive and negative power supply circuit. A step-up transformer and voltage-doubling rectifier circuit output a positive high voltage of 8-12kV and a low voltage of 4-6kV. The status indicator circuit features a 4-digit digital display. A 485 circuit is also connected to the microcontroller circuit. The status indicator circuit uses a GS1928 LED driver IC to drive a 4-digit digital display that alternately displays the output high voltage and load current.

[0020] Voltage and current sampling circuits such as Figure 2As shown, the high-voltage transformer and voltage-doubling rectifier module output a positive high voltage of 8-12 kV (the high voltage output terminal in the figure) and a low voltage of 4-6 kV (the high voltage output is twice the low voltage). The high and low voltage outputs are directly connected from the voltage-doubling rectifier module using 25 kV high-voltage cables. The high voltage terminal is connected to the tungsten filament of the purifier's metal electric field to ionize the air; the low voltage terminal is connected to the metal collector plate of the ion box to absorb oil smoke and dust. The negative terminal of the metal electric field is connected to the GND1 connector on the high-voltage power supply PCB. Load current sampling circuit: The ion box load current is connected to the PCB (i.e., the ISEN current sampling terminal) through the GND1 connector, then through the sampling resistor R95 to the digital ground GND, then through the current closed-loop control carbon film resistor R22, and back to the negative terminal of the voltage doubler board (i.e., the secondary terminal of the high-voltage transformer), completing a loop. Sampling resistor R95 converts the load current signal into a voltage signal, Visen. Here, a 1R / 2W carbon film resistor is used. The Visen voltage is very small, and the signal must be amplified for detection by the microcontroller. R95's value should not be too large. When the ion chamber arcs or shorts, the high-voltage pulse current is very large. A high-resistance sampling resistor would introduce high voltage to the PCB. One end of the resistor could spark to ground, potentially damaging surrounding CMOS chips. Capacitor C21, TVS diode D10, and varistor ZNR1 provide filtering and protection.

[0021] High-voltage output voltage sampling circuit: The 8-12 kV high voltage is attenuated by two series-connected 150M / 1W chip high-voltage resistors (R1 and R2). The voltage is then divided by R41 and R40 to produce a weak-voltage sampling signal (Vvsen). R41 is a 100K adjustable resistor to compensate for the large tolerance of the high-voltage resistor. The Vvsen signal is split into two paths: one for constant-voltage closed-loop control and low-voltage protection, and the other for AD detection to achieve real-time voltage tracking and display. Capacitor C23 and TVS diode D17 provide filtering and protection.

[0022] Voltage and current AD conversion and display circuit such as Figure 3 As shown, Figure 2 The voltage sampling signal Vvsen and current sampling signal Iisen cannot be directly fed into the microcontroller's I / O port for AD sampling. Instead, the signals must be followed or amplified by the LM258 before being connected to the microcontroller. This isolation measure ensures that the processed current and voltage signals do not affect the signals involved in the current and voltage closed-loop control, otherwise the dual closed-loop circuit becomes uncontrollable. In the figure, the Vvsen voltage sampling signal is forward-followed by the LM258 and fed into the microcontroller's AD port VAD, converting the analog value to digital. Software conversion then generates the corresponding real-time high-voltage output value of the power supply. In the figure, the Iisen current sampling signal passes through the inverting amplifier circuit formed by the LM258, R111, and R112, amplifying the current signal 200 times before entering the microcontroller's AD port IAD to complete the load current sampling.

[0023] Status indication circuit such as Figure 4 As shown, the GS1928 LED driver IC drives a 4-digit digital display to alternately display the output high voltage and load current. Using the AD values ​​corresponding to the current and voltage settings as a benchmark, software operations and linearization process the obtained real-time sampling values ​​to calculate the real-time voltage and current values ​​and display them on a 4-digit digital tube. The current and voltage are displayed alternately every 5 seconds.

[0024] Example 2: Based on Example 1: The single-chip microcomputer circuit adopts AT89 series single-chip microcomputer, which is low in price and easy to use.

[0025] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

[0026] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A current and voltage sampling and display system for a high-power high-voltage power supply, comprising an EMC module circuit, a 120V / 220V compatible circuit, a bridge rectifier circuit, a MOS tube drive circuit, a drive transformer circuit, a power management IC circuit, a power supply circuit, a constant voltage and current limiting double closed-loop circuit, a step-up transformer and a voltage doubling rectifier circuit, a voltage and current sampling circuit, a single-chip microcomputer circuit, a voltage and current AD conversion and display circuit and a status indication circuit, characterized in that: The EMC module circuit is connected to the bridge rectifier circuit through a 120V / 220V compatible circuit, the power supply circuit is connected to the power management IC circuit, the power management IC circuit is also connected to the MOS tube drive circuit through a drive transformer circuit, the MOS tube drive circuit is also connected to a step-up transformer and a voltage doubling rectifier circuit, the bridge rectifier circuit is also connected to the MOS tube drive circuit, the voltage and current sampling circuit is respectively connected to the step-up transformer and the voltage doubling rectifier circuit, the constant voltage and current limiting double closed-loop circuit and the single-chip microcomputer circuit, the single-chip microcomputer circuit is also respectively connected to the voltage and current AD conversion and display circuit and the status indication circuit, and the constant voltage and current limiting double closed-loop circuit is also connected to the power management IC circuit; the power supply circuit is a positive and negative 12V power supply circuit; the step-up transformer and the voltage doubling rectifier circuit output 8-12KV positive high voltage and 4-6KV low voltage; the status indication circuit is a 4-digit digital display screen, and the status indication circuit uses an LED driver IC GS1928 to drive a 4-digit digital display screen to display the output high voltage and load current in turn.

2. The current and voltage sampling and display system of a high-power high-voltage power supply according to claim 1 is characterized in that: The single chip microcomputer circuit is also connected with a 485 circuit.

3. The current and voltage sampling and display system of a high-power high-voltage power supply according to claim 1 is characterized in that: The single-chip microcomputer circuit adopts AT89 series single-chip microcomputer.

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