CN206892174U - HVDC pressure test General Current measurement apparatus - Google Patents

Abstract

The utility model relates to a general current measuring device for a high-voltage DC withstand voltage test, which belongs to the technical field of direct current measurement, and in particular relates to a general current measuring device for a high-voltage DC withstand voltage test. The utility model provides a high-safety, convenient-to-use general-purpose current measuring device for high-voltage direct current withstand voltage tests. The utility model includes a wireless measurement terminal and a handheld device. The main points of the structure are that the handheld device includes a shell 3, which is provided with a button 4, a liquid crystal screen 5, and a charging interface 13. The shell 3 is provided with a battery 6 for the handheld device and an antenna 7 for the handheld device. , LCD interface 8, handheld device MCU9, storage circuit 10, handheld device wireless communication module 11 and real-time clock circuit 12; MCU9 is connected with storage circuit 10, handheld device wireless communication module 11, real-time clock circuit 12, button 4 respectively, MCU9 It is connected with the liquid crystal screen 5 through the liquid crystal screen interface 8 .

Description

Universal current measuring device for HVDC withstand voltage test

technical field

The utility model belongs to the technical field of direct current measurement, in particular to a general current measuring device for high voltage direct current withstand voltage test.

Background technique

The preventive test of electrical equipment insulation is an important measure to ensure the safe operation of the equipment. The DC withstand voltage test can find hidden defects in the insulation in time. Therefore, the DC withstand voltage test is one of the test items that must be done when the power equipment is powered off for maintenance. However, in the high-voltage DC test, the microammeter used to measure the DC current is often disturbed or even damaged, and it is prone to vibration during transportation and testing, and has a high incidence of problems such as being impacted during the discharge of the high-voltage generator and failing to work normally. Moreover, due to the different sizes of high-voltage micro-amperes produced by different manufacturers, they cannot be replaced with each other. As a result, once the micro-ampere meter is damaged during the test, the entire test will not be able to be carried out for a long time.

Contents of the invention

The utility model aims at the above-mentioned problems, and provides a high-safety, convenient-to-use universal current measuring device for high-voltage DC withstand voltage tests.

In order to achieve the above object, the utility model adopts the following technical scheme. The utility model includes a wireless measurement terminal and a handheld device. The structural points of the handheld device include a shell 3, and the shell 3 is provided with a button 4, a liquid crystal screen 5 and a charging interface 13. The shell 3 is provided with a handheld device battery 6, a handheld device antenna 7, a liquid crystal screen interface 8, a handheld device MCU9, a storage circuit 10, a wireless communication module 11 for a handheld device, and a real-time clock circuit 12; The wireless communication module 11, the real-time clock circuit 12, and the button 4 are connected, the handheld device MCU 9 is connected to the LCD screen 5 through the LCD screen interface 8, the handheld device wireless communication module 11 is connected to the handheld device antenna 7, and the handheld device battery 6 is connected to the charging interface 13 .

Described measurement terminal comprises measurement terminal casing 15 and DC generator spare interface 27, and measurement terminal casing 15 is provided with antenna 14, current test line interface 17, power indicator light 18, protection indicator light 19, DC generator interface 20, current The test line interface 17 is connected to the current test lead 16, and the current test lead 16 is connected to the test object; the measurement terminal wireless module 21, the sampling resistor 22, the current measurement circuit 23, the protection relay 24, the measurement terminal MCU25 and the measurement terminal are arranged in the measurement terminal shell 15. The terminal battery 26, the measurement terminal equipment antenna 14 is connected to the measurement terminal wireless module 21, the current test line interface 17 is connected to the sampling resistor 22, the sampling resistor 22 is connected to the measurement terminal MCU25 through the current measurement circuit 23, and the control terminal of the protection relay 24 is connected to the measurement terminal respectively It is connected to the control signal output terminal of the measurement terminal MCU25 and the protection indicator light 19, and the DC generator interface 20 is connected to the output terminal of the high-voltage DC generator; the measurement terminal wireless module 21 is connected to the data interface of the measurement terminal MCU25.

As a preferred solution, the shell of the handheld device described in the utility model adopts an engineering plastic shell, the keys adopt PVC film keys, and the liquid crystal display adopts a 128×64 dot matrix display.

As another preferred solution, the handheld device wireless communication module 11 of the utility model is controlled by the handheld device MCU9, sends the command to read the measurement terminal 1 according to 2S time, and receives the report of the measurement data sent by the measurement terminal 1 by wireless. text, and then send it to the handheld device MCU9 for data processing; the handheld device MCU9 reads the time of the real-time clock through the peripheral interface, and then stores the time stamp and the calculated DC current data into the memory together, which is convenient for querying each test data results.

As another preferred solution, the measurement terminal housing 15 of the present invention is a cast aluminum housing.

As another preferred solution, the DC generator interface 20 of the utility model is an M8 internal thread interface, and one end of the DC generator backup interface 27 is an M8 external thread column, and the other end is a magnet.

As another preferred solution, the measurement terminal 1 of the utility model adopts two application modes: protection mode and measurement mode, and the two modes are set by the handheld device 2; when the measurement terminal 1 is applied in the protection mode, the protection relay is measured The control of the terminal MCU25 performs a pull-in action, short-circuits the circuit measurement circuit 23, bypasses the DC current into the test circuit, and plays a protective role against large current impacts; when the measurement terminal 1 is applied in the measurement mode, the protection relay is measured The control of the terminal MCU25 opens the action, the DC circuit is introduced into the sampling resistor 22, and after I/V conversion to a DC voltage, it is sent to the current measurement circuit 23, and then enters the internal A/D of the measurement terminal MCU25 after signal amplification processing, through Calculate and analyze to obtain accurate DC current measurement data, the measurement terminal MCU25 sends the data to the measurement terminal wireless module 21, the wireless module 21 sends wireless data packets to the handheld device 2, and uses the LCD screen to display the measurement data in real time.

As another preferred solution, the measuring terminal battery 26 of the utility model adopts a 3.7V rechargeable battery.

As another preferred solution, the measurement terminal MCU25 of the utility model adopts the PIC18F25K80 chip U3, the measurement terminal wireless module 21 adopts the REF24L01 chip, the current measurement circuit adopts the AD8603 chip, the power indicator light is a green light emitting diode DS1, and the protection indicator light is Red light emitting diode DS2.

Pin 1 of U3 is connected to one end of resistor R7 and one end of capacitor C20 through resistor R9, the other end of resistor R7 is connected to the SYS_VCC_3.3V power supply end, and the other end of capacitor C20 is connected to the first ground wire; pin 2 of U3 is connected to one end of resistor R30, resistor One end of R31 is connected to one end of capacitor C30, and the other end of resistor R30 is connected to pin 3 of XC6206 chip U1, one end of capacitor C2, pin 5 of PS3120 chip, one end of capacitor C16, one end of resistor R4, one end of capacitor C14, and one end of switch S1; capacitor C2 The other end is respectively connected to the first ground wire, the other end of capacitor C16, the other end of capacitor C14, pin 2 of the PS3120 chip, one end of capacitor C15, and the negative pole of the measuring terminal battery; the positive pole of the measuring terminal battery is connected to the other end of switch S1, and the other end of capacitor C15 is respectively It is connected to the SYS_VCC_5V power supply terminal and pin 1 of the PS3120 chip; the other end of the resistor R4 is connected to the pin 3 of the PS3120 chip.

The other end of the capacitor C30 is connected to the first ground wire, the other end of the resistor R31, pin 1 of U1, one end of the capacitor C1, one end of the resistor R5, one end of the capacitor C13, and one end of the resistor R3. The other end of the resistor R5 is connected to the cathode of the light-emitting diode DS1 to emit The anode of diode DS1 is connected to pin 2 of U1, the other end of capacitor C1, SYS_VCC_3.3V power supply, one end of resistor R1, and the other end of capacitor C13; the other end of resistor R1 is connected to one end of capacitor C6, SYS_AVCC_3.3V power supply, and one end of capacitor C5 The other end of the capacitor C5 is connected to the second ground, the other end of the capacitor C6 and the other end of the resistor R3 respectively.

Pin 3 of U3 is connected to pin 1 of the AD8603 chip, pin 2 of the AD8603 chip is connected to the second ground wire, pin 5 of the AD8603 chip is connected to one end of the capacitor C7, one end of the capacitor C23, and one end of the resistor R6, and the other end of the capacitor C7 is connected to the capacitor The other end of C23 is connected to the second ground wire, and the other end of resistor R6 is connected to the SYS_AVCC_3.3V power supply end; the 4 pins of the AD8603 chip are respectively connected to one end of the capacitor C9 and one end of the resistor R12, and the other end of the capacitor C9 is respectively connected to the end of the resistor R14 and the end of the AD8603 chip. The other end of the resistor R12 is connected to one end of the resistor R13, one end of the capacitor C10, and one end of the first inductor, and the other end of the resistor R14 is connected to the other end of the resistor R13, one end of the resistor R15, the other end of the capacitor C10, and one end of the second inductor. The other end of the resistor R15 is connected to the REF2.0V power supply end; the other end of the first inductor is connected to the end of the BC301 discharge tube G1, the normally closed point of the protection relay K1, the end of the resistor R21, the end of the resistor R20, and the test object; the other end of the second inductor is respectively connected to the The other end of the BC301 discharge tube G1 is connected to the normally open point of the protection relay K1, and the switching end of the protection relay K1 is respectively connected to the other end of the resistor R21, the other end of the resistor R20, and the positive pole of the high-voltage DC generator.

One end of the control terminal of the protection relay K1 is connected to the SYS_VCC_5V power supply, one end of the 750-ohm resistor, the cathode of the diode D1, and the collector of the output terminal of the optocoupler, and the other end of the 750-ohm resistor is connected to the anode of the diode DS2, and the cathode of the diode DS2 is respectively connected to the anode of the diode D1 and the NPN transistor The collector of Q1, the other end of the control terminal of the protection relay K1, and the collector of the NPN transistor Q2 are connected. The base of the NPN transistor Q2 is connected to the emitter of the NPN transistor Q1 and one end of the 10K ohm resistor, and the other end of the 10K ohm resistor is respectively connected to the first ground wire, The emitter of the NPN transistor Q2 is connected to one end of the resistor R17, the base of the NPN transistor Q1 is connected to the emitter of the output terminal of the optocoupler through the resistor R16, the cathode of the light-emitting diode at the input terminal of the optocoupler is connected to the other end of the resistor R17, and the anode of the light-emitting diode at the input terminal of the optocoupler is connected to the other end of the resistor R17. The 12 pins of U3 are connected.

Pin 6 of U3 is connected to the first ground wire and pin 8 of U3 through capacitor C24, pin 9 of U3 is connected to one end of crystal oscillator Y1 and one end of capacitor C21, and the other end of capacitor C21 is connected to the first ground wire and one end of capacitor C22. , the other end of the capacitor C22 is respectively connected to the other end of the crystal oscillator Y1 and pin 10 of U3.

Pin 17 of U3 is connected to pin 19 of the REF24L01 chip, pin 18 of U3 is connected to pin 18 of the chip REF24L01, pin 19 of U3 is connected to the first ground wire and one end of capacitor C25, and the other end of capacitor C25 is connected to pin 20 of U3 , SYS_VCC_3.3V power terminal connected.

Pin 1 of the REF24L01 chip is connected to pin 2 of the REF24L01 chip, SYS_VCC_3.3V power supply terminal, one terminal of capacitor C19, and one terminal of capacitor C18, and the other end of capacitor C18 is respectively connected to the other end of capacitor C19 and the first ground wire; Connect one end of capacitor C3 and pin 1 of LM117-2.0 chip through resistor R2, the other end of capacitor C3 is connected to the second ground wire, pin 3 of LM117-2.0 chip, and one end of capacitor C4, and the other end of capacitor C4 is respectively connected to LM117-2.0 chip 2 feet, REF2.0V power terminal connected.

Secondly, the MCU of the handheld device described in the utility model adopts the C8051F002 chip U4, the real-time clock circuit adopts the DS1302 chip, the wireless communication module of the handheld device adopts the REF24L01 chip, the storage circuit adopts the M25P128 chip, and the LCD screen adopts the B12864 type LCD screen.

Pin 1 of U4 is connected to pin 18 of the REF24L01 chip, pins 2 to 5 of U4 are respectively connected to pins 11 to 14 of the B12864 LCD screen, pin 6 of U4 is connected to the ground wire and one end of capacitor C19, and the other end of capacitor C19 is respectively It is connected with SYS_VCC_3.3V power supply terminal and pin 7 of U4, and 8~11, 14, 15, 22~24 of U4 are respectively connected with key ports K1~K9; 16 pins of U4 are respectively connected with one end of resistor R11 and 5 pins of DS1302 chip. The other end of resistor R11 is connected to one end of resistor R10, SYS_VCC_3.3V power supply end, one end of capacitor C18, one end of resistor R12, and pin 1 of DS1302 chip, the other end of capacitor C18 is grounded, and pin 8 of DS1302 chip is connected to the positive electrode of the battery Connected, the negative electrode of the handheld device battery is connected to the ground wire and the 4-pin of the DS1302 chip, the 2-pin of the DS1302 chip is connected to the 3-pin of the DS1302 chip through the crystal oscillator, and the 6-pin of the DS1302 chip is connected to the other end of the resistor R12 and one end of the 100 ohm resistor , the other end of the 100 ohm resistor is connected to pin 17 of U4.

Pin 18 of U4 is respectively connected to one end of the resistor R15 and one end of the capacitor C8 through the resistor R16, the other end of the capacitor C8 is grounded, and the other end of the resistor R15 is connected to the SYS_VCC_3.3V power supply end.

Pin 20 of U4 is connected to pin 7 of the REF24L01 chip, pin 1 of the REF24L01 chip is connected to pin 2 of the REF24L01 chip, SYS_VCC_3.3V power supply terminal, one end of capacitor C5, one end of capacitor C1, and the other end of capacitor C1 is connected to the other end of capacitor C5 , Connected to the ground wire; the 18 and 19 pins of the REF24L01 chip are respectively connected to the 1 and 44 pins of U4.

Pin 21 of U4 is connected to pin 7 of the DS1302 chip, and pins 25-27, 32, 35, 38-41 of U4 are connected to pins 6-4, 15, 16, and 7-10 of the B12864 LCD screen; Pin 20 of the screen is connected to one end of capacitor C4, one end of capacitor C20, pin 1 of the B12864 LCD screen, and the ground wire. One end of resistor R14 is connected to pin 19 of the B12864 LCD screen, the toggle end of rheostat R17 is connected to pin 3 of the B12864 LCD screen, the other end of rheostat R17 is connected to pin 18 of the B12864 LCD screen, and the other end of resistor R14 is connected to capacitor C20 The other end is connected to pin 17 of the B12864 LCD screen.

Pin 36 of U4 is connected to pin 7 of M25P128 chip, pin 37 of U4 is connected to pin 16 of M25P128 chip, pin 42 of U4 is connected to pin 8 of M25P128 chip, pin 43 of U4 is connected to pin 15 of M25P128 chip; pin 1 of M25P128 chip is connected to SYS_VCC_3.3V power supply terminal, M25P128 chip 2 pins, one end of capacitor C16 is connected, the other end of capacitor C16 is grounded; M25P128 chip 10 pins are respectively connected to the ground wire, one end of capacitor C17, the other end of capacitor C17 is respectively connected to M25P128 chip 9 pins, SYS_VCC_3.3V connected to the power supply.

The SYS_VCC_3.3V power terminal is respectively connected to the anode of the green light-emitting diode DS1, one end of the capacitor C11, the positive electrode of the capacitor C3, the positive electrode of the capacitor C2, one end of the capacitor C9, and the 2 pins of the LM117 chip U2, and the 3 pins of U2 are respectively connected to the one end of the capacitor C10, and the handheld device The positive pole of the battery and the positive pole of the charging interface are connected, and the negative pole of the charging interface is respectively connected with the negative pole of the battery of the handheld device, the other end of capacitor C10, pin 1 of U2, the other end of capacitor C9, the negative pole of capacitor C2, the negative pole of capacitor C3, the other end of capacitor C11, and one end of resistor R5 , the other end of the resistor R5 is connected to the cathode of the light-emitting diode DS1.

The 28 pins of U4 are respectively connected to the SYS_VCC_3.3V power supply terminal and one end of the capacitor C21, and the other end of the capacitor C21 is respectively connected to the ground wire and the 29 pins of U4; the 30 pins of U4 are connected to one end of the 16M crystal oscillator and one end of the capacitor C7, and the other end of the capacitor C7 One end is connected to the ground wire and one end of capacitor C6, and the other end of capacitor C6 is connected to the other end of the 16M crystal oscillator and pin 31 of U4.

In addition, the button port K1 of the utility model is connected to one end of the number 9 button, one end of the number 0 button, one end of the * button, and one end of the number button. The button port K2 is respectively connected to one end of the number 5 button, one end of the number 6 button, and one end of the number 7 button. One end of the button and one end of the number 8 button are connected. The button port K3 is respectively connected to one end of the number 10 button, one end of the number 11 button, one end of the number 12 button, and one end of the number 13 button. The button port K4 is respectively connected to one end of the ok symbol button, one end of the menu symbol button, One end of the cancel symbol button and one end of the return symbol button are connected, and the button port K5 is respectively connected with one end of the number up symbol button, one end of the down symbol button, one end of the left symbol button, and one end of the right symbol button.

The button port K6 is connected to the other end of the number up symbol button, the other end of the ok symbol button, the other end of the number 1 button, the other end of the number 5 button, and the other end of the number 9 button, and the button port K7 is respectively connected to the other end of the number down symbol button, menu The other end of the symbol button, the other end of the number 2 button, the other end of the number 6 button, and the other end of the number 0 button are connected, and the button port K8 is connected to the other end of the number left symbol button, the other end of the cancel symbol button, the other end of the number 3 button, and the number 7 The other end of the button and the other end of the * button are connected, and the button port K9 is respectively connected with the other end of the number right symbol button, the other end of the return symbol button, the other end of the number 4 button, the other end of the number 8 button, and the other end of the . button.

The utility model has beneficial effects.

Based on the wireless DC current measurement technology, the utility model develops a universal micro-ampere DC measurement device in high-voltage tests, which can be applied to all high-voltage DC test measurement occasions, and uses wireless communication technology to transmit data to handheld devices in real time. The convenient test also protects personal safety. The utility model studies the high-voltage direct current micro-ampere current measurement technology and the mechanism of the high-voltage direct current discharge impact, and designs a related protection circuit. A hand-held device based on wireless communication and capable of reading the data of the measuring device in real time was developed, and finally a general current measuring device in the DC withstand voltage test was formed.

The utility model realizes that electric equipment of various voltage levels can use a common current measurement technology in the high-voltage DC withstand voltage test, and provides a new type of wireless direct current measuring device for the DC withstand voltage test of each electric equipment.

The wireless measurement terminal of the utility model is connected in series between the high-voltage DC generator and the test product (power equipment), and can measure the current value applied by the high-voltage DC generator to the power equipment in real time, and can transmit the measurement data to the on the handheld device. The other is a wireless handheld device. The handheld device with a liquid crystal display can display the DC current value measured by the wireless measurement terminal in real time, and has the functions of setting parameters and data storage. Zigbee wireless radio frequency transmission can be used for data interaction between the wireless measurement terminal and the handheld device.

The wireless measurement terminal of the utility model can accurately measure the DC value applied to the power equipment, and has two modes of measurement and protection. The measurement mode can perform real-time measurement of DC current; the protection mode can carry out the electronic measurement part of the measurement terminal Bypass protection, the impact current of the test can be released to the ground through the bypass, so as not to damage the internal electronic circuit of the measurement terminal. Handheld devices and measurement terminals exchange data through radio frequency, which not only realizes electrical isolation, protects the personal safety of operators, but also avoids the difficulty of manual remote reading of data. The handheld device can record multiple sets of measurement data and wirelessly transmit them to the background computer for easy data processing.

The utility model utilizes the wireless radio frequency technology to achieve electrical isolation between the operator and the high-voltage test equipment; the utility model can read the current measurement data received by the handheld device on the spot, which is more intuitive.

The DC current applied in the test enters the internal measurement circuit of the measurement terminal, and the DC current value applied to the device under test can be measured and transmitted to the handheld device 2 through wireless communication. The LCD screen on the handheld device can display it in real time measurement results. The current application mode can be changed by pressing the button, and the current time, stored data number, etc. can be set.

Description of drawings

The utility model will be further described below in conjunction with the accompanying drawings and specific embodiments. The scope of protection of the utility model is not limited to the expression of the following content.

Fig. 1 is the structural representation of the utility model.

2 and 3 are structural schematic diagrams of the handheld device of the present invention.

Fig. 4 is a schematic diagram of the structure of the measurement terminal of the present invention.

5-8 are schematic diagrams of the measurement terminal circuit of the utility model.

9 to 14 are circuit schematic diagrams of the handheld device of the present invention.

detailed description

As shown in the figure, the utility model includes a wireless measurement terminal 1 and a handheld device 2. The handheld device includes a casing 3, and the casing 3 is provided with buttons 4, a liquid crystal screen 5 and a charging interface 13. The casing 3 is provided with a battery 6 for the handheld device, Handheld device antenna 7, liquid crystal screen interface 8, handheld device MCU9, storage circuit 10, handheld device wireless communication module 11 and real-time clock circuit 12; , the button 4 is connected, the handheld device MCU9 is connected to the LCD screen 5 through the LCD screen interface 8, the handheld device wireless communication module 11 is connected to the handheld device antenna 7, and the handheld device battery 6 is connected to the charging interface 13.

Described measurement terminal comprises measurement terminal casing 15 and DC generator spare interface 27, and measurement terminal casing 15 is provided with antenna 14, current test line interface 17, power indicator light 18, protection indicator light 19, DC generator interface 20, current The test line interface 17 is connected to the current test lead 16, and the current test lead 16 is connected to the test object; the measurement terminal wireless module 21, the sampling resistor 22, the current measurement circuit 23, the protection relay 24, the measurement terminal MCU25 and the measurement terminal are arranged in the measurement terminal shell 15. The terminal battery 26, the measurement terminal equipment antenna 14 is connected to the measurement terminal wireless module 21, the current test line interface 17 is connected to the sampling resistor 22, the sampling resistor 22 is connected to the measurement terminal MCU25 through the current measurement circuit 23, and the control terminal of the protection relay 24 is connected to the measurement terminal respectively It is connected to the control signal output terminal of the measurement terminal MCU25 and the protection indicator light 19, and the DC generator interface 20 is connected to the output terminal of the high-voltage DC generator; the measurement terminal wireless module 21 is connected to the data interface of the measurement terminal MCU25.

The casing of the handheld device is made of engineering plastics, the buttons are made of PVC film buttons, and the liquid crystal display is a 128×64 dot matrix display.

The handheld device wireless communication module 11 is controlled by the handheld device MCU9, sends an order to read the measurement terminal 1 according to 2S time, and receives the message of the measurement data sent by the measurement terminal 1 by wireless, and then sends it to the handheld device MCU9 for data processing. deal with.

The handheld device MCU9 reads the time of the real-time clock through the peripheral interface, and then stores the time stamp and the calculated DC current data into the memory together, so that it is convenient to query the data results of each test.

The measuring terminal casing 15 is made of cast aluminum.

The DC generator interface 20 is an M8 internal thread interface, one end of the DC generator backup interface 27 is an M8 external thread column, and the other end is a magnet. If the output ends of individual high-voltage DC generators adopt a planar installation structure. The DC generator spare interface 27 is designed, and one end of the machine is an M8 externally threaded column, which can be directly installed on the DC generator interface 20 of the measurement terminal 1, and the other end adopts a high-performance magnet, which is completely and reliably adsorbed on the DC generator of the planar structure. Generator output for universal mounting of measuring terminals.

The measurement terminal 1 adopts two application modes: protection mode and measurement mode, and the two modes are set by the handheld device 2; when the measurement terminal 1 is applied in the protection mode, the protection relay is controlled by the measurement terminal MCU25 to perform a pull-in action, and the The circuit measurement circuit 23 is short-circuited, bypassing the DC current into the test circuit, which plays a protective role against large current impact; when the measurement terminal 1 is applied in the measurement mode, the protection relay is opened under the control of the measurement terminal MCU25, and the DC circuit Introduced into the sampling resistor 22, converted to a DC voltage by I/V, sent to the current measurement circuit 23, and then entered into the internal A/D of the measurement terminal MCU25 after signal amplification processing, and accurate DC current measurement data is obtained through calculation and analysis. The measurement terminal MCU25 sends data to the measurement terminal wireless module 21, and the wireless module 21 sends wireless data packets to the handheld device 2, and uses the liquid crystal screen to display the measurement data in real time.

The measuring terminal battery 26 is a 3.7V rechargeable battery.

The measurement terminal MCU25 adopts the PIC18F25K80 chip U3, the measurement terminal wireless module 21 adopts the REF24L01 chip, the current measurement circuit adopts the AD8603 chip, the power indicator light is a green light-emitting diode DS1, and the protection indicator light is a red light-emitting diode DS2.

Pin 1 of U3 is connected to one end of resistor R7 and one end of capacitor C20 through resistor R9, the other end of resistor R7 is connected to the SYS_VCC_3.3V power supply end, and the other end of capacitor C20 is connected to the first ground wire; pin 2 of U3 is connected to one end of resistor R30, resistor One end of R31 is connected to one end of capacitor C30, and the other end of resistor R30 is connected to pin 3 of XC6206 chip U1, one end of capacitor C2, pin 5 of PS3120 chip, one end of capacitor C16, one end of resistor R4, one end of capacitor C14, and one end of switch S1; capacitor C2 The other end is respectively connected to the first ground wire, the other end of capacitor C16, the other end of capacitor C14, pin 2 of the PS3120 chip, one end of capacitor C15, and the negative pole of the measuring terminal battery; the positive pole of the measuring terminal battery is connected to the other end of switch S1, and the other end of capacitor C15 is respectively It is connected to the SYS_VCC_5V power supply terminal and pin 1 of the PS3120 chip; the other end of the resistor R4 is connected to the pin 3 of the PS3120 chip.

The other end of the capacitor C30 is connected to the first ground wire, the other end of the resistor R31, pin 1 of U1, one end of the capacitor C1, one end of the resistor R5, one end of the capacitor C13, and one end of the resistor R3. The other end of the resistor R5 is connected to the cathode of the light-emitting diode DS1 to emit The anode of diode DS1 is connected to pin 2 of U1, the other end of capacitor C1, SYS_VCC_3.3V power supply, one end of resistor R1, and the other end of capacitor C13; the other end of resistor R1 is connected to one end of capacitor C6, SYS_AVCC_3.3V power supply, and one end of capacitor C5 The other end of the capacitor C5 is connected to the second ground, the other end of the capacitor C6 and the other end of the resistor R3 respectively.

Pin 3 of U3 is connected to pin 1 of the AD8603 chip, pin 2 of the AD8603 chip is connected to the second ground wire, pin 5 of the AD8603 chip is connected to one end of the capacitor C7, one end of the capacitor C23, and one end of the resistor R6, and the other end of the capacitor C7 is connected to the capacitor The other end of C23 is connected to the second ground wire, and the other end of resistor R6 is connected to the SYS_AVCC_3.3V power supply end; the 4 pins of the AD8603 chip are respectively connected to one end of the capacitor C9 and one end of the resistor R12, and the other end of the capacitor C9 is respectively connected to the end of the resistor R14 and the end of the AD8603 chip. The other end of the resistor R12 is connected to one end of the resistor R13, one end of the capacitor C10, and one end of the first inductor, and the other end of the resistor R14 is connected to the other end of the resistor R13, one end of the resistor R15, the other end of the capacitor C10, and one end of the second inductor. The other end of the resistor R15 is connected to the REF2.0V power supply end; the other end of the first inductor is connected to the end of the BC301 discharge tube G1, the normally closed point of the protection relay K1, the end of the resistor R21, the end of the resistor R20, and the test object; the other end of the second inductor is respectively connected to the The other end of the BC301 discharge tube G1 is connected to the normally open point of the protection relay K1, and the switching end of the protection relay K1 is respectively connected to the other end of the resistor R21, the other end of the resistor R20, and the positive pole of the high-voltage DC generator.

One end of the control terminal of the protection relay K1 is connected to the SYS_VCC_5V power supply, one end of the 750-ohm resistor, the cathode of the diode D1, and the collector of the output terminal of the optocoupler, and the other end of the 750-ohm resistor is connected to the anode of the diode DS2, and the cathode of the diode DS2 is respectively connected to the anode of the diode D1 and the NPN transistor The collector of Q1, the other end of the control terminal of the protection relay K1, and the collector of the NPN transistor Q2 are connected. The base of the NPN transistor Q2 is connected to the emitter of the NPN transistor Q1 and one end of the 10K ohm resistor, and the other end of the 10K ohm resistor is respectively connected to the first ground wire, The emitter of the NPN transistor Q2 is connected to one end of the resistor R17, the base of the NPN transistor Q1 is connected to the emitter of the output terminal of the optocoupler through the resistor R16, the cathode of the light-emitting diode at the input terminal of the optocoupler is connected to the other end of the resistor R17, and the anode of the light-emitting diode at the input terminal of the optocoupler is connected to the other end of the resistor R17. The 12 pins of U3 are connected.

Pin 6 of U3 is connected to the first ground wire and pin 8 of U3 through capacitor C24, pin 9 of U3 is connected to one end of crystal oscillator Y1 and one end of capacitor C21, and the other end of capacitor C21 is connected to the first ground wire and one end of capacitor C22. , the other end of the capacitor C22 is respectively connected to the other end of the crystal oscillator Y1 and pin 10 of U3.

Pin 17 of U3 is connected to pin 19 of the REF24L01 chip, pin 18 of U3 is connected to pin 18 of the chip REF24L01, pin 19 of U3 is connected to the first ground wire and one end of capacitor C25, and the other end of capacitor C25 is connected to pin 20 of U3 , SYS_VCC_3.3V power terminal connected.

Pin 1 of the REF24L01 chip is connected to pin 2 of the REF24L01 chip, SYS_VCC_3.3V power supply terminal, one terminal of capacitor C19, and one terminal of capacitor C18, and the other end of capacitor C18 is respectively connected to the other end of capacitor C19 and the first ground wire; Connect one end of capacitor C3 and pin 1 of LM117-2.0 chip through resistor R2, the other end of capacitor C3 is connected to the second ground wire, pin 3 of LM117-2.0 chip, and one end of capacitor C4, and the other end of capacitor C4 is respectively connected to LM117-2.0 chip 2 feet, REF2.0V power terminal connected.

The handheld device MCU adopts C8051F002 chip U4, the real-time clock circuit adopts DS1302 chip, the handheld device wireless communication module adopts REF24L01 chip, the storage circuit adopts M25P128 chip, and the LCD screen adopts B12864 type LCD screen.

Pin 1 of U4 is connected to pin 18 of the REF24L01 chip, pins 2 to 5 of U4 are respectively connected to pins 11 to 14 of the B12864 LCD screen, pin 6 of U4 is connected to the ground wire and one end of capacitor C19, and the other end of capacitor C19 is respectively It is connected with SYS_VCC_3.3V power supply terminal and pin 7 of U4, and 8~11, 14, 15, 22~24 of U4 are respectively connected with key ports K1~K9; 16 pins of U4 are respectively connected with one end of resistor R11 and 5 pins of DS1302 chip. The other end of resistor R11 is connected to one end of resistor R10, SYS_VCC_3.3V power supply end, one end of capacitor C18, one end of resistor R12, and pin 1 of DS1302 chip, the other end of capacitor C18 is grounded, and pin 8 of DS1302 chip is connected to the positive electrode of the battery Connected, the negative electrode of the handheld device battery is connected to the ground wire and the 4-pin of the DS1302 chip, the 2-pin of the DS1302 chip is connected to the 3-pin of the DS1302 chip through the crystal oscillator, and the 6-pin of the DS1302 chip is connected to the other end of the resistor R12 and one end of the 100 ohm resistor , the other end of the 100 ohm resistor is connected to pin 17 of U4.

Pin 18 of U4 is respectively connected to one end of the resistor R15 and one end of the capacitor C8 through the resistor R16, the other end of the capacitor C8 is grounded, and the other end of the resistor R15 is connected to the SYS_VCC_3.3V power supply end.

Pin 20 of U4 is connected to pin 7 of the REF24L01 chip, pin 1 of the REF24L01 chip is connected to pin 2 of the REF24L01 chip, SYS_VCC_3.3V power supply terminal, one end of capacitor C5, one end of capacitor C1, and the other end of capacitor C1 is connected to the other end of capacitor C5 , Connected to the ground wire; the 18 and 19 pins of the REF24L01 chip are respectively connected to the 1 and 44 pins of U4.

Pin 21 of U4 is connected to pin 7 of the DS1302 chip, and pins 25-27, 32, 35, 38-41 of U4 are connected to pins 6-4, 15, 16, and 7-10 of the B12864 LCD screen; Pin 20 of the screen is connected to one end of capacitor C4, one end of capacitor C20, pin 1 of the B12864 LCD screen, and the ground wire. One end of resistor R14 is connected to pin 19 of the B12864 LCD screen, the toggle end of rheostat R17 is connected to pin 3 of the B12864 LCD screen, the other end of rheostat R17 is connected to pin 18 of the B12864 LCD screen, and the other end of resistor R14 is connected to capacitor C20 The other end is connected to pin 17 of the B12864 LCD screen.

Pin 36 of U4 is connected to pin 7 of M25P128 chip, pin 37 of U4 is connected to pin 16 of M25P128 chip, pin 42 of U4 is connected to pin 8 of M25P128 chip, pin 43 of U4 is connected to pin 15 of M25P128 chip; pin 1 of M25P128 chip is connected to SYS_VCC_3.3V power supply terminal, M25P128 chip 2 pins, one end of capacitor C16 is connected, the other end of capacitor C16 is grounded; M25P128 chip 10 pins are respectively connected to the ground wire, one end of capacitor C17, the other end of capacitor C17 is respectively connected to M25P128 chip 9 pins, SYS_VCC_3.3V connected to the power supply.

The SYS_VCC_3.3V power terminal is respectively connected to the anode of the green light-emitting diode DS1, one end of the capacitor C11, the positive electrode of the capacitor C3, the positive electrode of the capacitor C2, one end of the capacitor C9, and the 2 pins of the LM117 chip U2, and the 3 pins of U2 are respectively connected to the one end of the capacitor C10, and the handheld device The positive pole of the battery and the positive pole of the charging interface are connected, and the negative pole of the charging interface is respectively connected with the negative pole of the battery of the handheld device, the other end of capacitor C10, pin 1 of U2, the other end of capacitor C9, the negative pole of capacitor C2, the negative pole of capacitor C3, the other end of capacitor C11, and one end of resistor R5 , the other end of the resistor R5 is connected to the cathode of the light-emitting diode DS1.

The 28 pins of U4 are respectively connected to the SYS_VCC_3.3V power supply terminal and one end of the capacitor C21, and the other end of the capacitor C21 is respectively connected to the ground wire and the 29 pins of U4; the 30 pins of U4 are connected to one end of the 16M crystal oscillator and one end of the capacitor C7, and the other end of the capacitor C7 One end is connected to the ground wire and one end of capacitor C6, and the other end of capacitor C6 is connected to the other end of the 16M crystal oscillator and pin 31 of U4.

The button port K1 is respectively connected to one end of the number 9 button, one end of the number 0 button, one end of the * number button, and one end of the number button. The button port K2 is respectively connected to one end of the number 5 button, one end of the number 6 button, one end of the number 7 button, and one end of the number 8 button. One end of the button is connected, and the button port K3 is respectively connected to one end of the number 10 button, one end of the number 11 button, one end of the number 12 button, and one end of the number 13 button, and the button port K4 is respectively connected to one end of the ok symbol button, one end of the menu symbol button, one end of the cancel symbol button, One end of the return symbol button is connected, and the button port K5 is respectively connected with one end of the number up symbol button, one end of the down symbol button, one end of the left symbol button, and one end of the right symbol button.

The button port K6 is connected to the other end of the number up symbol button, the other end of the ok symbol button, the other end of the number 1 button, the other end of the number 5 button, and the other end of the number 9 button, and the button port K7 is respectively connected to the other end of the number down symbol button, menu The other end of the symbol button, the other end of the number 2 button, the other end of the number 6 button, and the other end of the number 0 button are connected, and the button port K8 is connected to the other end of the number left symbol button, the other end of the cancel symbol button, the other end of the number 3 button, and the number 7 The other end of the button and the other end of the * button are connected, and the button port K9 is respectively connected with the other end of the number right symbol button, the other end of the return symbol button, the other end of the number 4 button, the other end of the number 8 button, and the other end of the . button.

As shown in Figure 5, when K1 is switched to terminal 6, it is the protection mode. K1 is controlled by the MCU. When it is pulled in, it is equivalent to bypassing the back-end acquisition circuit. When the current impacts, it directly introduces a large current into the primary circuit. When released, the applied current can flow through the measurement circuit and finally be measured. The signal comes in from input 1, is stepped down by R13, and then flows out from input 2 into the test object, and the differential signal at both ends of the voltage of R13 is tested, and the current is measured. By controlling K1, the measurement terminal has a dual mode of measurement and protection, which can avoid interference and damage to the electronic measurement part caused by the impact in the DC test.

PGD and PGC ports are ports for downloading programs.

The BC301 discharge tube plays the role of voltage shock protection, and L1 plays the role of current shock protection.

It can be understood that the above specific description of the utility model is only used to illustrate the utility model and is not limited to the technical solutions described in the embodiments of the utility model. Those of ordinary skill in the art should understand that the utility model can still be Modifications or equivalent replacements are carried out to achieve the same technical effect; as long as the needs of use are met, they are all within the protection scope of the present utility model.

Claims (8)

1. HVDC pressure test General Current measurement apparatus, including wireless measurement terminal and handheld device, it is characterised in that Handheld device includes shell（3）, shell（3）On be provided with button（4）, liquid crystal display（5）And charging inlet（13）, shell（3）It is interior It is provided with handheld device battery（6）, handheld device antenna（7）, LCD Interface（8）, handheld device MCU（9）, storage circuit （10）, handheld device wireless communication module（11）And real time clock circuit（12）；Handheld device MCU（9）Respectively with storage circuit （10）, handheld device wireless communication module（11）, real time clock circuit（12）, button（4）It is connected, handheld device MCU（9）Pass through LCD Interface（8）With liquid crystal display（5）It is connected, handheld device wireless communication module（11）With handheld device antenna（7）It is connected, hand Holding equipment battery（6）With charging inlet（13）It is connected；

The measuring terminals include measuring terminals shell（15）With DC generator spare interface（27）, measuring terminals shell（15） On be provided with antenna（14）, testing current line interface（17）, power supply indicator（18）, protection indicator lamp（19）, DC generator Interface（20）, testing current line interface（17）With testing current lead（16）It is connected, testing current lead（16）Connect test product；Measurement Terminal enclosure（15）Inside it is provided with measuring terminals wireless module（21）, sampling resistor（22）, current measurement circuit（23）, protection after Electrical equipment（24）, measuring terminals MCU（25）With measuring terminals battery（26）, measuring terminals device antenna（14）Connect measuring terminals without Wire module（21）, testing current line interface（17）Connect sampling resistor（22）, sampling resistor（22）Pass through current measurement circuit （23）With measuring terminals MCU（25）It is connected, protective relay（24）Control terminal and measuring terminals respectively with measuring terminals MCU （25）Control signal output, protection indicator lamp（19）It is connected, DC generator interface（20）It is connected to HVDC The output end of device；Measuring terminals wireless module（21）It is connected to measuring terminals MCU（25）Data-interface on.

2. HVDC pressure test General Current measurement apparatus according to claim 1, it is characterised in that described hold sets Standby shell uses engineering plastics shell, and button is to use 128 × 64 lattice displays using PVC film button, LCDs Screen.

3. HVDC pressure test General Current measurement apparatus according to claim 1, it is characterised in that the measurement is eventually End housing（15）For cast aluminium material shell.

4. HVDC pressure test General Current measurement apparatus according to claim 1, it is characterised in that the direct current hair Raw device interface（20）For M8 internal thread interface, DC generator spare interface（27）One end be M8 external thread column, the other end For magnet.

5. HVDC pressure test General Current measurement apparatus according to claim 1, it is characterised in that the measurement is eventually End-cell（26）Using 3.7V rechargeable batteries.

6. HVDC pressure test General Current measurement apparatus according to claim 1, it is characterised in that the measurement is eventually Hold MCU（25）Using PIC18F25K80 chip U3, measuring terminals wireless module（21）Using REF24L01 chips, current measurement Circuit uses AD8603 chips, and power supply indicator is green light LED DS1, protection indicator lamp is red light-emitting diode DS2；

U3 1 pin is connected with resistance R7 one end, electric capacity C20 one end respectively by resistance R9, another termination SYS_VCC_ of resistance R7 3.3V power ends, electric capacity C20 the first ground wires of another termination；U3 2 pin respectively with resistance R30 one end, resistance R31 one end, electric capacity C30 one end is connected, the resistance R30 other ends respectively 3 pin with XC6206 chips U1, electric capacity C2 one end, PS3120 chips 5 pin, Electric capacity C16 one end, resistance R4 one end, electric capacity C14 one end, switch S1 one end are connected；The electric capacity C2 other ends respectively with the first ground wire, The electric capacity C16 other ends, the electric capacity C14 other ends, 2 pin of PS3120 chips, electric capacity C15 one end, measuring terminals GND are connected； Measuring terminals anode connect switch the S1 other ends, the electric capacity C15 other ends respectively with SYS_VCC_5V power ends, PS3120 chips 1 pin is connected；Another pin of termination PS3120 chips 3 of resistance R4；

The electric capacity C30 other ends respectively with the first ground wire, the resistance R31 other ends, U1 1 pin, electric capacity C1 one end, resistance R5 one end, Electric capacity C13 one end, resistance R3 one end are connected, and the resistance R5 other ends are connected with light emitting diode DS1 negative electrodes, light emitting diode DS1 Anode 2 pin with U1, the electric capacity C1 other ends, SYS_VCC_3.3V power ends, resistance R1 one end, electric capacity C13 other end phases respectively Even；The resistance R1 other ends are connected with electric capacity C6 one end, SYS_AVCC_3.3V power ends, electric capacity C5 one end respectively, and electric capacity C5 is another End is connected with the second ground wire, the electric capacity C6 other ends, the resistance R3 other ends respectively；

U3 3 pin are connected with 1 pin of AD8603 chips, and 2 pin of AD8603 chips connect the second ground wire, 5 pin point of AD8603 chips Be not connected with electric capacity C7 one end, electric capacity C23 one end, resistance R6 one end, the electric capacity C7 other ends respectively with the electric capacity C23 other ends, Two ground wires are connected, another termination SYS_AVCC_3.3V power ends of resistance R6；4 pin of AD8603 chips respectively with electric capacity C9 one end, Resistance R12 one end is connected, and 3 pin of the electric capacity C9 other ends respectively with resistance R14 one end, AD8603 chips are connected, and resistance R12 is another End is connected with resistance R13 one end, electric capacity C10 one end, first inductance one end respectively, and the resistance R14 other ends are another with resistance R13 respectively One end, resistance R15 one end, the electric capacity C10 other ends, second inductance one end are connected, another termination REF2.0V power ends of resistance R15； The first inductance other end respectively with BC301 discharge tube G1 one end, the normally closed points of protective relay K1, resistance R21 one end, resistance R20 One end, test product are connected；The second inductance other end is connected with the BC301 discharge tube G1 other ends, protective relay K1 opened points respectively, Protective relay K1 struck sides are connected with the resistance R21 other ends, the resistance R20 other ends, high-voltage D.C. generator positive pole respectively；

Protective relay K1 control terminals one end respectively with SYS_VCC_5V power supplys, 750 Ohmic resistance one end, diode D1 negative electrodes, Optocoupler output colelctor electrode is connected, and the 750 Ohmic resistance other ends are connected with diode DS2 anodes, diode DS2 negative electrodes respectively with Diode D1 anodes, NPN triode Q1 colelctor electrode, the protective relay K1 control terminals other end, NPN triode Q2 colelctor electrode phases Even, NPN triode Q2 base stages are connected with NPN triode Q1 emitter stage, 10K Ohmic resistances one end respectively, and 10K Ohmic resistances are another End is connected with the first ground wire, NPN triode Q2 emitter stages, resistance R17 one end respectively, and NPN triode Q1 base stage passes through resistance R16 It is connected with optocoupler output emitter stage, optocoupler input light-emitting diodes tube cathode is connected with the resistance R17 other ends, optocoupler input Light-emitting diodes tube anode is connected with U3 12 pin；

U3 6 pin are connected by 8 pin of the electric capacity C24 respectively with the first ground wire, U3, U3 9 pin respectively with crystal oscillator Y1 one end, electric capacity C21 one end is connected, and the electric capacity C21 other ends are connected with the first ground wire, electric capacity C22 one end respectively, the electric capacity C22 other ends respectively with crystalline substance The shake Y1 other ends, U3 10 pin are connected；

U3 17 pin are connected with 19 pin of REF24L01 chips, and U3 18 pin are connected with 18 pin of REF24L01 chips, and the 19 of U3 Pin is connected with the first ground wire, electric capacity C25 one end respectively, the electric capacity C25 other ends 20 pin with U3, SYS_VCC_3.3V power supplys respectively End is connected；

1 pin of REF24L01 chips respectively 2 pin with REF24L01 chips, SYS_VCC_3.3V power ends, electric capacity C19 one end, Electric capacity C18 one end is connected, and the electric capacity C18 other ends are connected with the electric capacity C19 other ends, the first ground wire respectively；SYS_AVCC_3.3V electricity Source is connected with electric capacity C3 one end, the pin of LM117-2.0 chips 1 respectively by resistance R2, the electric capacity C3 other ends respectively with the second ground Line, the pin of LM117-2.0 chips 3, electric capacity C4 one end are connected, the electric capacity C4 other ends respectively with the pin of LM117-2.0 chips 2, REF2.0V Power end is connected.

7. HVDC pressure test General Current measurement apparatus according to claim 1, it is characterised in that described hold sets Standby MCU uses C8051F002 chip U4, and real time clock circuit uses DS1302 chips, and handheld device wireless communication module uses REF24L01 chips, storage circuit use M25P128 chips, and liquid crystal display uses B12864 model liquid crystal displays；

U4 1 pin is connected with the pin of REF24L01 chips 18, U4 2~5 pin 11~14 pin with B12864 model liquid crystal displays respectively Corresponding to be connected, U4 6 pin are connected with ground wire, electric capacity C19 one end respectively, and the electric capacity C19 other ends are electric with SYS_VCC_3.3V respectively Source, U4 7 pin are connected, U4 8~11,14,15,22~24 connections corresponding with Key pad port K1~K9 respectively；U4 16 pin 5 pin with resistance R11 one end, DS1302 chips are connected respectively, the resistance R11 other ends respectively with resistance R10 one end, SYS_VCC_ 3.3V power ends, electric capacity C18 one end, resistance R12 one end, 1 pin of DS1302 chips are connected, electric capacity C18 other ends ground connection, 8 pin of DS1302 chips are connected with handheld device anode, handheld device GND respectively with ground wire, DS1302 chips 4 pin are connected, and 2 pin of DS1302 chips are connected by crystal oscillator with 3 pin of DS1302 chips, 6 pin of DS1302 chips respectively with electricity The resistance R12 other ends, 100 Ohmic resistance one end are connected, and the 100 Ohmic resistance other ends are connected with U4 17 pin；

U4 18 pin are connected with resistance R15 one end, electric capacity C8 one end respectively by resistance R16, electric capacity C8 other ends ground connection, resistance Another termination SYS_VCC_3.3V power ends of R15；

U4 20 pin are connected with 7 pin of REF24L01 chips, 1 pin of REF24L01 chips respectively 2 pin with REF24L01 chips, SYS_VCC_3.3V power ends, electric capacity C5 one end, electric capacity C1 one end are connected, the electric capacity C1 other ends respectively with the electric capacity C5 other ends, Ground wire is connected；1,44 pin of 18,19 pin of REF24L01 chips respectively with U4 are corresponding to be connected；

U4 21 pin are connected with 7 pin of DS1302 chips, U4 25~27,32,35,38~41 pin and B12864 model liquid crystal displays 6~4,15,16,7~10 pin corresponding connect；20 pin of B12864 model liquid crystal displays respectively with electric capacity C4 one end, electric capacity C20 mono- End, 1 pin, the ground wire of B12864 model liquid crystal displays be connected, the electric capacity C4 other ends respectively 2 pin with B12864 model liquid crystal displays, SYS_VCC_3.3V power ends, rheostat R17 one end, resistance R14 one end, 19 pin of B12864 model liquid crystal displays are connected, variable resistance Device R17 struck sides are connected with 3 pin of B12864 model liquid crystal displays, the rheostat R17 other ends and the 18 of B12864 model liquid crystal displays Pin is connected, and 17 pin of the resistance R14 other ends respectively with the electric capacity C20 other ends, B12864 model liquid crystal displays are connected；

U4 36 pin are connected with the pin of M25P128 chips 7, and U4 37 pin are connected with the pin of M25P128 chips 16, U4 42 pin with The pin of M25P128 chips 8 is connected, and U4 43 pin are connected with the pin of M25P128 chips 15；The pin of M25P128 chips 1 respectively with SYS_VCC_ 3.3V power ends, the pin of M25P128 chips 2, electric capacity C16 one end are connected, electric capacity C16 other ends ground connection；The pin point of M25P128 chips 10 Be not connected with ground wire, electric capacity C17 one end, the electric capacity C17 other ends respectively with the pin of M25P128 chips 9, SYS_VCC_3.3V power ends It is connected；

SYS_VCC_3.3V power ends respectively with green light LED DS1 anodes, electric capacity C11 one end, electric capacity C3 positive poles, electric capacity C2 positive poles, electric capacity C9 one end, LM117 chips U2 2 pin are connected, U2 3 pin respectively with electric capacity C10 one end, handheld device battery Positive pole, charging inlet positive pole are connected, charging inlet negative pole respectively with handheld device GND, the electric capacity C10 other ends, U2 1 Pin, the electric capacity C9 other ends, electric capacity C2 negative poles, electric capacity C3 negative poles, the electric capacity C11 other ends, resistance R5 one end are connected, and resistance R5 is another Terminate light emitting diode DS1 negative electrodes；

U4 28 pin are connected with SYS_VCC_3.3V power ends, electric capacity C21 one end respectively, the electric capacity C21 other ends respectively with ground wire, U4 29 pin are connected；U4 30 pin are connected with 16M crystal oscillators one end, electric capacity C7 one end respectively, the electric capacity C7 other ends respectively with ground wire, Electric capacity C6 one end is connected, and 31 pin of the electric capacity C6 other ends respectively with the 16M crystal oscillators other end, U4 are connected.

8. HVDC pressure test General Current measurement apparatus according to claim 7, it is characterised in that the button end Mouth K1 is connected with digital 9 button one end, digital 0 button one end, * buttons one end, buttons one end respectively, Key pad port K2 It is connected respectively with digital 5 button one end, digital 6 button one end, digital 7 button one end, digital 8 button one end, Key pad port K3 It is connected respectively with digital 10 button one end, digital 11 button one end, digital 12 button one end, digital 13 button one end, button end Mouthful K4 respectively with ok symbol keys one end, menu symbol keys one end, cancel symbol keys one end, return symbol keys one End be connected, Key pad port K5 respectively with digital up symbol keys one end, down symbol keys one end, left symbol keys one end, Right symbol keys one end is connected；

Key pad port K6 respectively with the digital up symbol keys other end, the ok symbol keys other end, the digital 1 button other end, number The button other end of word 5, the digital 9 button other ends are connected, Key pad port K7 respectively with the digital down symbol keys other end, menu The symbol keys other end, the digital 2 button other ends, the digital 6 button other ends, the digital 0 button other end are connected, Key pad port K8 It is another with the digital left symbol keys other end, the cancel symbol keys other end, the digital 3 button other ends, digital 7 buttons respectively One end, the * button other ends are connected, Key pad port K9 respectively with the digital right symbol keys other end, return symbol keys The other end, the digital 4 button other ends, the digital 8 button other ends, the button other ends are connected.