High potential voltage isolation sampling circuit

Abstract

The utility model relates to a kind of high potential voltage isolation sampling circuit, including high potential drive circuit and low potential hall sampling circuit, high potential drive circuit includes stabilized DC power supply VC2, current-limiting resistor R1, drive resistance R2 and triode V1, the DC output positive terminal of VC2 is connected with the one end of R1, the other end of R1 is connected together with the collector of V1 through low potential N1, the output positive terminal of the sampling power supply VC1 is connected with the one end of R2, the other end of R2 is connected together with the base of V1, low potential hall sampling circuit includes hall current sensor N1, sampling resistance R3 and filter capacitor C1, the sampling end of N1 is connected with the one end of R3, the one end of C1, the other end of R3 and the other end of C1 are grounded.The utility model uses voltage to current isolation transmission mode, samples the DC output voltage working on high potential, and circuit structure is simple, reliability is high, and cost is low.

Description

Technical Field

[0001] This utility model relates to the field of power supply technology, and in particular to a high-potential voltage isolation sampling circuit. Background Technology

[0002] In high-energy physics and high-power microwave transmitters, some DC power supplies operate floating at high potentials, such as bias power supplies and filament power supplies. These power supplies typically output voltages ranging from a few volts to several hundred volts, operating on high voltages ranging from tens to hundreds of kilovolts. Voltage sampling and monitoring of these power supplies presents a significant challenge in engineering design.

[0003] For sampling and monitoring of DC power supplies floating at high potentials, isolated transmission technology is typically required. Currently, the most common isolation coupling method is optocoupler. Optocoupler is an isolated transmission method that uses a light-emitting diode (LED) at the transmitting end to convert an electrical signal into an optical signal, and then uses a photodiode at the receiving end to convert the optical signal back into an electrical signal. A common method for converting electrical signals to optical signals is voltage-frequency modulation (V / F-F / V). This circuit first converts the input voltage signal into a frequency signal, then uses optocouplers (fiber optic, high-voltage optocouplers, etc.) to achieve long-distance transmission of the frequency signal, and finally converts the frequency signal back into a voltage signal at the receiving end. This V / F-F / V conversion technology offers good isolation performance, is technologically mature, and has a wide range of applications. However, it suffers from poor linearity and temperature stability. Furthermore, because the voltage-frequency conversion at high potentials requires integrated chip circuits and fiber optic connectors, and high potentials require low-voltage power supplies, the circuitry is complex, has poor anti-interference capabilities, and is easily damaged by arcing or discharge at high potentials, resulting in low reliability in practical applications. Utility Model Content

[0004] To address the existing technical problems, this utility model provides a high-potential voltage isolation sampling circuit.

[0005] The specific content of this utility model is as follows: A high-potential voltage isolation sampling circuit includes a high-potential driving circuit and a low-potential Hall sampling circuit. The high-potential driving circuit includes a regulated DC power supply VC2, a current-limiting resistor R1, a driving resistor R2, and a transistor V1. The low-potential Hall sampling circuit includes a Hall current sensor N1, a sampling resistor R3, and a filter capacitor C1. The positive DC output terminal of the regulated DC power supply VC2 is connected to one end of the current-limiting resistor R1. The other end of the current-limiting resistor R1 passes through the low-potential Hall current sensor N1 and is connected to the collector of the transistor V1. The positive output terminal of the power supply VC1 to be sampled is connected to one end of the driving resistor R2. The other end of the driving resistor R2 is connected to the base of the transistor V1. The emitter of the transistor V1, the negative terminal of the regulated DC power supply VC2, and the negative terminal of the power supply VC1 to be sampled are connected together. The sampling terminal of the Hall current sensor N1 is connected to one end of the sampling resistor R3 and one end of the filter capacitor C1. The other end of the sampling resistor R3 and the other end of the filter capacitor C1 are grounded.

[0006] Furthermore, the regulated DC power supply VC2 is 5V, 12V, or 15V, generated by adding a secondary winding to the main circuit transformer of the power supply VC1 to be sampled, followed by rectification and filtering, and then passing it through a three-terminal regulator.

[0007] Furthermore, the current-limiting resistor R1 has a resistance value of several ohms to tens of ohms. The resistance value of the current-limiting resistor R1 is adjusted according to the current flowing through the Hall current sensor N1, and is in the A-level range.

[0008] Furthermore, the voltage value of the sampling resistor R3 is between 0 and 5V.

[0009] Furthermore, the high and low potentials are isolated by a high-voltage line, and one end of the current-limiting resistor R1 passes through the low-potential Hall current sensor N1 via the high-voltage line.

[0010] Furthermore, when sampling and monitoring the negative power supply, a negative regulated DC power supply VC2 is used, and the transistor V1 is replaced with a PNP transistor.

[0011] This invention employs a voltage-to-current isolation transmission method to sample the DC output voltage that is floating at a high potential. The circuit structure is simple, highly reliable, and low in cost. It can be used for circuit closed-loop control and display, facilitating online adjustment and monitoring. Attached Figure Description

[0012] The present invention will be further explained below with reference to the accompanying drawings.

[0013] Figure 1 This is a schematic diagram of the high-potential voltage isolation sampling circuit of this utility model. Figure 1 ;

[0014] Figure 2This is a schematic diagram of the high-potential voltage isolation sampling circuit of this utility model. Figure 2 . Detailed Implementation

[0015] Combination Figure 1 This utility model discloses a high-potential voltage isolation sampling circuit, comprising a high-potential driving circuit and a low-potential Hall sampling circuit. The high-potential driving circuit includes a regulated DC power supply VC2, a current-limiting resistor R1, a driving resistor R2, a transistor V1, and a high-voltage line. The regulated DC power supply VC2 is typically 5V, 12V, or 15V, and can be generated by adding a secondary winding to the main circuit transformer of the power supply VC1 for rectification and filtering, followed by a three-terminal regulator. The positive output terminal of the regulated DC power supply VC2 is connected to one end of the current-limiting resistor R1, and the other end of the current-limiting resistor R1 is connected to the collector of the transistor V1 via the high-voltage line through the low-potential Hall current sensor N1. The resistance of the current-limiting resistor R1 ranges from a few ohms to tens of ohms, and its value is adjusted according to the current flowing through the Hall current sensor N1, typically in the order of amperes (A). The positive output terminal of the sampling power supply VC1 is connected to one end of the driving resistor R2, and the other end of the driving resistor R2 is connected to the base of transistor V1. The driving resistor R2 is used to make transistor V1 operate in the linear amplification region. The resistance value of the driving resistor R2 is adjusted according to the base current of V1, typically ranging from several kilohms to hundreds of kilohms. The emitter of transistor V1, the negative terminal of VC2, and the negative terminal of VC1 are connected together. The low-potential Hall sampling circuit includes a Hall current sensor N1, a sampling resistor R3, and a filter capacitor C1. The sampling terminal of the Hall current sensor N1 is connected to one end of the sampling resistor R3 and one end of the filter capacitor C1, while the other ends of the sampling resistor R3 and the filter capacitor C1 are grounded. The voltage value of the sampling resistor R3 is between 0 and 5V. Isolation between high and low potentials is achieved through a high-voltage line.

[0016] The present invention will be further explained below with reference to specific examples.

[0017] Take a 500V positive bias voltage sampling circuit as an example. This positive bias power supply operates by floating on a 50KV high voltage.

[0018] The high-potential voltage isolation sampling circuit includes a +5V power supply, a current-limiting resistor R1, a drive resistor R2, a transistor V1, a high-voltage line, a Hall current sensor N1, a sampling resistor R3, and a filter capacitor C1.

[0019] A 5V DC power supply is connected to the collector of transistor V1 via resistor R1 and a high-voltage line. The high-voltage line passes through Hall current sensor N1 in the direction of current flow. The current flowing through N1 is set to 1A, so the resistance of R1 is approximately 4Ω. Considering the power dissipation of R1 is 4W, R1 is selected as 3.9Ω / 10W. The isolation voltage of the high-voltage line is 50KV, and with a certain margin, a high-voltage line with a withstand voltage rating of 70KV is selected. A 500V forward bias power supply drives transistor V1 through resistor R2, causing transistor V1 to operate in the linear amplification region. The resistance of R2 is determined by the base current of transistor V1. Using a transistor with a gain of 200, it is known that transistor V1 operates in the linear amplification region when the base current is approximately 5mA. Therefore, the resistance of R2 in this circuit is approximately 100kΩ, and considering the power dissipation of R2 is approximately 2.5W. Therefore, R2 is selected as 100kΩ / 6W (actually constructed using three 300kΩ / 2W resistors connected in parallel). The negative terminal of 5V and the emitter of V1 are connected together to the negative terminal of 500V. The current passing through the Hall current sensor N1 is approximately 1A. Based on the primary-secondary sampling ratio, the sampling resistor R3 is selected as 1kΩ, and the filter capacitor is 0.1μF. In this way, the VOUT voltage varies between 0 and 5V. By adding VOUT to the closed-loop circuit of the 500V positive bias power supply, online adjustment and monitoring of the positive bias power supply can be achieved.

[0020] When sampling and monitoring a negative power supply, a negative regulated DC power supply VC2 is used, and transistor V1 is replaced with a PNP transistor. By simply adjusting the high-potential isolation sampling circuit of the positive power supply, sampling and monitoring of the negative power supply floating at a high potential can be achieved. Figure 2 As shown.

[0021] This invention employs a transistor operating in the linear amplification region, adjusting the current flowing through the high-voltage line by regulating the voltage difference between the collector and emitter. High- and low-potential isolation is achieved by passing the high-voltage line through a Hall effect current transformer. The Hall effect current transformer performs high-potential current sampling and voltage conversion, while the transformer itself operates at a low potential. The circuit uses a voltage-to-current isolation transmission method. The high-potential loop contains no voltage-to-frequency conversion integrated chip or optoelectronic connector; all components are passive, resulting in a simple circuit with strong resistance to arcing and strong interference, and high reliability. High- and low-potential isolation is achieved through a high-voltage insulated wire, simplifying the circuit and making it easy to implement. The use of a Hall effect sensor for current sampling and voltage conversion is technically mature, offering good linearity and temperature stability. The circuit uses fewer components, simplifying design and manufacturing, facilitating debugging, and reducing costs. The high-potential voltage isolation sampling circuit has a wide range of applications; simple component modifications can meet the needs of positive and negative power supplies, making it easy to promote.

[0022] Many specific details have been set forth in the above description to provide a full understanding of this utility model. However, the above description is only a preferred embodiment of this utility model, and this utility model can be implemented in many other ways different from those described herein. Therefore, this utility model is not limited to the specific embodiments disclosed above. Furthermore, any person skilled in the art can make many possible variations and modifications to the technical solution of this utility model using the methods and techniques disclosed above, or modify it into equivalent embodiments with equivalent changes, without departing from the scope of the technical solution of this utility model. Any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of this utility model, without departing from the content of the technical solution of this utility model, shall still fall within the protection scope of the technical solution of this utility model.

Claims

1. A high-potential voltage isolation sampling circuit, characterized in that: The circuit includes a high-potential driving circuit and a low-potential Hall sampling circuit. The high-potential driving circuit includes a regulated DC power supply VC2, a current-limiting resistor R1, a driving resistor R2, and a transistor V1. The low-potential Hall sampling circuit includes a Hall current sensor N1, a sampling resistor R3, and a filter capacitor C1. The positive DC output terminal of the regulated DC power supply VC2 is connected to one end of the current-limiting resistor R1. The other end of the current-limiting resistor R1 passes through the low-potential Hall current sensor N1 and is connected to the collector of the transistor V1. The positive output terminal of the power supply VC1 to be sampled is connected to one end of the driving resistor R2. The other end of the driving resistor R2 is connected to the base of the transistor V1. The emitter of the transistor V1, the negative terminal of the regulated DC power supply VC2, and the negative terminal of the power supply VC1 to be sampled are connected together. The sampling terminal of the Hall current sensor N1 is connected to one end of the sampling resistor R3 and one end of the filter capacitor C1. The other ends of the sampling resistor R3 and the filter capacitor C1 are grounded.

2. The high-potential voltage isolation sampling circuit according to claim 1, characterized in that: The regulated DC power supply VC2 is generated by adding a secondary winding to the main circuit transformer of the power supply VC1 to be sampled, followed by rectification and filtering, and then passing it through a three-terminal regulator.

3. The high-potential voltage isolation sampling circuit according to claim 1, characterized in that: The resistance value of the current-limiting resistor R1 is adjusted according to the current flowing through the Hall current sensor N1, and is in the A-level range.

4. The high-potential voltage isolation sampling circuit according to claim 1, characterized in that: The voltage value of the sampling resistor R3 is between 0 and 5V.

5. The high-potential voltage isolation sampling circuit according to claim 1, characterized in that: The high and low potentials are isolated by a high-voltage line, and one end of the current-limiting resistor R1 passes through the low-potential Hall current sensor N1 via the high-voltage line.

6. The high-potential voltage isolation sampling circuit according to claim 1, characterized in that: When sampling and monitoring the negative power supply, a negative regulated DC power supply VC2 is used, and transistor V1 is a PNP transistor.

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