Safety tools insulation resistance tester

Abstract

A safety tool insulation resistance tester includes a handheld host housing, a working circuit board, a charger and electrodes, wherein the electrodes are semi-encircling structures; the working circuit board, its main board is composed of MCU, AD acquisition input, shaping filter input, resistance sampling input, relay switching sampling range, high voltage wiring L end, low voltage wiring E end, buzzer circuit and LCM interface, and its control board is composed of relay switching high voltage output, power switch, start / stop switch, alarm gear selection, one-button power on / off circuit, step-down and power supply circuit and charging interface circuit. Its advantages are small size, good safety, high measurement accuracy, only one person holding the tester can measure the insulation resistance of the insulating rod, the measurement is carried out automatically, and the measurement results are displayed on a large-screen LCD; in addition, the insulation resistance tester increases the measurement contact surface of the electrode, can realize the continuous sliding test of the insulating rod, and the test can completely cover the surface of the insulating rod.

Description

Technical Field

[0001] The invention relates to an insulation resistance tester, in particular to a safety tool insulation resistance tester, which is applied to laboratory or on-site insulation test of power transformation and contact network specialties. Background Art

[0002] The de-icing, foreign body handling, and electrical testing of railway power supply equipment must be completed with the help of insulating tools, and insulating rods are the main insulating tool materials in the operation; to ensure the safety of the operation, the insulating rods must have sufficient mechanical strength and electrical insulation strength. At present, the insulating rods used in the operation are made of high-strength glass fiber with epoxy resin, which should have good electrical insulation strength. However, due to the impact of production process quality problems, material formulation problems, poor use and storage, and product aging, the electrical insulation performance will be reduced. Therefore, the insulation test of the insulating rod cannot be ignored.

[0003] China Railway Corporation has such safety operation rules in high-speed railway traction substations and conventional traction substations: "Before using insulating tools, they should be carefully checked for damage, deformation, and failure, and a 2500V insulation megohmmeter or insulation tester should be used to perform segmented insulation testing (electrode width 2cm, pole width 2cm), and the resistance value should not be less than 700MΩ"; China Railway Corporation's "Safety Work Regulations for Contact Networks" stipulates that "Before each use of insulating tools, they should be carefully checked for damage, and the effective insulating part should be wiped with a clean and dry rag, and then the insulation resistance of the effective insulating part should be measured in sections with a 2500V megohmmeter (electrode width 2cm, pole width 2cm), which should not be less than 100MΩ, or the insulation resistance of the entire effective insulating part should not be less than 10,000MΩ."

[0004] However, at present, the traditional hand-cranked megohmmeter is mostly used for on-site insulation resistance measurement. The traditional hand-cranked megohmmeter has the following defects in on-site insulation resistance measurement: first, the measurement accuracy is low and the error is large. Because it is an artificial shaking power generation, the high voltage accuracy generated is not high, and the display mode is a pointer display, which will inevitably have a large measurement error; second, the contact between the measuring electrode and the insulating rod is a point contact, and the measurement position selection is relatively random, and the surface of the insulating rod cannot be completely covered; third, the shaking insulation resistance measurement requires at least 2 people to cooperate, and the strict testing process takes a long time; fourth, it is unsafe, 2500V, which is a high voltage, once the tester is slightly negligent, it will cause electric shock to the personnel; fifth, it cannot meet the requirements of the regulations, the electrode width requirement of 2cm is not met, and now only a single test lead is used for point measurement, and the requirement of 2cm between the poles cannot be guaranteed by existing means. Therefore, due to the above inconveniences, the use of traditional hand-cranked megohmmeters to shake the insulation resistance of the insulating rod is often a formality, which buries a large safety hazard for on-site operations. The above are the shortcomings of the prior art. Summary of the invention

[0005] The purpose of the present invention is to provide an insulation resistance tester for safety tools. The insulation resistance tester for safety tools is small in size, has good safety, and high measurement accuracy. Only one person can measure the insulation resistance of an insulating rod. The measurement is performed automatically, and the measurement result is displayed on a large-screen liquid crystal. In addition, the insulation resistance tester increases the measurement contact surface of the electrode, and can realize continuous sliding test of the insulating rod. The test can completely cover the surface of the insulating rod, and the test value is displayed in real time. The alarm range can be set, and the equipment can be tested when it is turned on. The display mode is the insulation resistance value. If it exceeds the set alarm range, an alarm prompt will be given.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] The present invention discloses a safety tool insulation resistance tester, comprising a handheld host housing, a working circuit board, a charger and electrodes. A liquid crystal screen observation window is provided at the upper front portion of the handheld host housing, and the working circuit board is installed in the handheld host housing. The electrode is a semi-encircling structure, which includes a line end L-end plug and a ground end E-end plug; the working circuit board includes a main board and a control board, and the main board is composed of an MCU, an AD acquisition input, a shaping filter input, a resistance sampling input, a relay switching sampling range, a high-voltage wiring L-end, a low-voltage wiring E-end, a buzzer circuit and an LCM interface, wherein the high-voltage wiring L-end has an L-end hole-type terminal P2, the low-voltage wiring E-end has an E-end hole-type terminal P5, and the control board It is composed of a relay switching high-voltage output, a power switch, a start / stop switch, an alarm gear selection, a one-button power on / off circuit, a step-down and power supply circuit, and a charging interface circuit. The power switch has a power button switch S1, the start / stop switch has a start / stop button switch S3, and the alarm gear selection has an alarm setting toggle switch S2. The main board and the control board are connected by connecting wires through reserved welding holes. The MCU is used to control the detection of the power on and off of the tester, as well as the detection of starting and stopping the test, control the selection input of the alarm gear and set the over-limit alarm value, control the buzzer to stop, switch the relay state, control the reception of sampled data, and display the data on the LCD display module through internal calculation processing. The LCD screen displays the insulation resistance value of the tested insulating rod; the AD acquisition input is used to convert the two-way analog voltage signals after rectification and filtering by the shaping filter input into digital signals, and transmit them to the single-chip microcomputer in the MCU through the SPI communication method; the shaping filter input is used to precisely rectify and filter the two-way analog voltage signals collected by the resistance sampling input, and then transmit them to the AD acquisition input; the resistance sampling input is used to collect the analog voltage signal at the L end of the high-voltage wiring and the analog current signal at the E end of the low-voltage wiring, and convert them into two-way analog voltage signals after resistance voltage division, and input them to the shaping filter input, so as to calculate the insulation resistance of the tested insulating rod through the resistance voltage division method through the single-chip microcomputer in the MCU; the relay switching sampling range is used By judging the size of the sampled current, the relay is used to switch the gear range, thereby expanding the test range; the high-voltage wiring L end is used to connect the line end L end plug of the electrode; the low-voltage wiring E end is used to connect the ground end E end plug of the electrode; the buzzer circuit is used to realize the buzzer sounding stop, and when the test result exceeds the warning value, the buzzer sounds an alarm; the LCM interface is used to connect the LCD liquid crystal display module, control the reset, backlight and data output of the LCD liquid crystal display module, and display the test items and test data of the tester; the relay switching high-voltage output is used to control the high-voltage module to output high voltage through the relay; the power switch is used to turn on or off the tester; the start / stop switch is used to start or stop the test of the tester;The alarm gear selection is used to set the alarm gear signal and input the set alarm gear signal into the single-chip microcomputer in the MCU, which is processed internally by the single-chip microcomputer in the MCU to set the over-limit alarm value; the one-button power on / off circuit is used to provide the power supply voltage V+ and is connected to the single-chip microcomputer in the MCU, and the single-chip microcomputer in the MCU controls the detection of the power switch state; the step-down and power supply circuit is used to reduce the power supply voltage V+ to the system operating voltage, and provide the system with 5V DC voltage, -9V DC voltage and 9V DC voltage; the charging interface circuit is used to charge the internal rechargeable battery with an external charger, Connect the relay switching high voltage output to power the relay contact common end in the relay switching high voltage output, and connect the one-key switch circuit to provide the power supply voltage V+ through the one-key switch circuit; the upper end of the handheld host housing is provided with an extension hole of the L-end hole-type terminal P2 and an extension hole of the E-end hole-type terminal P5, the front middle and lower positions of the handheld host housing are provided with a first button exposure hole of the power button switch S1 and a second button exposure hole of the start / stop button switch S3, and the lower end of the handheld host housing is provided with an operating handle exposure port of the alarm setting toggle switch S2. ;

[0008] The MCU of the present invention includes a single-chip microcomputer U1, a power supply filter capacitor C3, a crystal oscillator circuit, a power-on reset circuit, a program download circuit, and resistors R45 and R46. The crystal oscillator circuit includes a crystal oscillator Y1 and capacitors C1 and C2. The power-on reset circuit includes a resistor R3 and a capacitor C4. The program download circuit includes a 4-wire single-row pin interface J1, resistors R1 and R2, and light-emitting diodes D1 and D2. The AD acquisition input includes an AD conversion chip U3, a low-power voltage reference chip U4, a crystal oscillator Y7, capacitors C6-C8, and resistors R11 and R47; the shaping filter input includes a precision rectifier circuit and a filter circuit. The precision rectifier circuit contains op amp chips U5 and U6, resistors R16 and R21, and capacitors C11 and C16. The filter circuit contains resistors R12 to R15, capacitors C9 and C10, and bidirectional TVS diodes D8 and D10; the resistor sampling input contains high-voltage resistors R28 and R48 to R52, high-voltage terminal P1, and precision resistors R35 to R37; the relay switching sampling range contains relay K1, diode D6, transistor Q3, and resistor R 27; the relay switching high-voltage output contains high-voltage module U8, relay K2, transistor Q5 and resistor R42; the high-voltage wiring L end contains L-end hole-type terminal P2; the low-voltage wiring E end contains E-end hole-type terminal P5; the buzzer circuit contains buzzer LS1, transistor Q4, light-emitting diode D7 and resistors R26 and R43; the power switch contains power button switch S1; the start / stop switch contains start / stop button switch S3 and resistor R44; the alarm gear selection contains alarm setting toggle switch S2 and resistors R38~R4 1; the LCM interface has a liquid crystal interface J2, and the liquid crystal interface J2 is plugged with an LCD display module; the one-button switch circuit has resistors R7-R10, diodes D4 and D5, and transistors Q1 and Q2; the step-down and power supply circuit has a DC / DC converter control circuit U2, resistors R4-R6, electrolytic capacitors CT1 and CT2, capacitor C5, diode D3, inductor L0, power module U7, and tantalum capacitors C21 and C22; the charging interface circuit has a charging interface J0, wiring terminals P3 and P4, and a rechargeable battery;

[0009] The connection relationship is as follows: in the charging interface circuit, the second pin of the charging interface J0 is connected to the wiring terminal P3 and grounded, the first pin of the charging interface J0 is connected to the wiring terminal P4, the negative and positive electrodes of the rechargeable battery are connected to the wiring terminals P3 and P4 respectively, and the charging interface J0 is connected to an external charger for charging the rechargeable battery; in the one-button switch circuit, one end of the resistor R7 is connected to the emitter of the transistor Q2 and the wiring terminal P4 in the charging interface circuit, the other end of the resistor R7 is connected to the base of the transistor Q2 and one end of the resistor R8, and the collector output of the transistor Q2 is powered. The power supply voltage V+, the other end of the resistor R8 is connected to the positive electrode of the diode D4 and the collector of the transistor Q1, the emitter of the transistor Q1 is grounded, the base of the transistor Q1 is connected to one end of the resistors R9 and R10, the other end of the resistor R9 is grounded, the cathodes of the diodes D4 and D5 are connected to one end of the power button switch S1 in the power switch, and the other end of the power button switch S1 is grounded; in the step-down and power supply circuit, the 6th and 4th pins of the DC / DC converter control circuit U2 are connected to the power supply voltage V+ and the ground respectively, and the 1st, 7th and The 8th pin is connected to one end of the resistor R4, the other end of the resistor R4 is connected to the power supply voltage V+, and is also connected to the positive electrode of the electrolytic capacitor CT1, the negative electrode of the electrolytic capacitor CT1 is grounded, the 2nd pin of the DC / DC converter control circuit U2 is connected to the negative electrode of the diode D3, and is also connected to one end of the inductor L0, the positive electrode of the diode D3 is grounded, the other end of the inductor L0 is connected to the positive electrode of the electrolytic capacitor CT2 and one end of the resistor R5, and outputs a 5V DC voltage at the same time, the negative electrode of the electrolytic capacitor CT2 is grounded, the other end of the resistor R5 is connected to one end of the resistor R6, and is also connected The 5th pin of the DC / DC converter control circuit U2 and the other end of the resistor R6 are grounded, the 3rd pin of the DC / DC converter control circuit U2 is connected to one end of the capacitor C5, the other end of the capacitor C5 is grounded, the 1st pin of the power module U7 is connected to a 5V DC voltage, the 2nd and 5th pins of the power module U7 are grounded, the 4th and 6th pins of the power module U7 output -9V DC voltage and 9V DC voltage respectively, the negative electrode of the tantalum capacitor C21 is connected to the -9V DC voltage, the positive electrode is connected to the negative electrode of the tantalum capacitor C22 and grounded, and the positive electrode of the tantalum capacitor C22 is connected to the 9V DC voltage;In the MCU, the 38th pin of the single-chip microcomputer U1 is connected to the 5V DC voltage, the 16th pin of the single-chip microcomputer U1 is grounded GND, between the crystal oscillator circuit and the single-chip microcomputer U1, the two ends of the crystal oscillator Y1 are respectively connected to the 15th and 14th pins of the single-chip microcomputer U1, between the power-on reset circuit and the single-chip microcomputer U1, one end of the capacitor C4 is connected to the 5V DC voltage, and the other end is connected to the 4th pin of the single-chip microcomputer U1, in the program download circuit, the 1st and 2nd pins of the 4-wire single-row pin interface J1 are respectively connected to the 5V DC voltage and the ground, and one end of the resistors R1 and R2 are respectively connected to the 4-wire single-row pin interface J 1, the other ends of resistors R1 and R2 are connected to the cathodes of light-emitting diodes D1 and D2 respectively, and the anodes of light-emitting diodes D1 and D2 are connected to 5V DC voltage. Between the program download circuit and the single-chip microcomputer U1, the 3rd and 4th pins of the 4-wire single-row pin interface J1 are connected to the 7th and 5th pins of the single-chip microcomputer U1 respectively. One end of resistor R45 is connected to the power supply voltage V+, and the other end is connected to one end of resistor R46, and is also connected to the 40th pin of the single-chip microcomputer U1. The other end of resistor R46 is grounded; between the one-button switch circuit and the MCU, resistor R1 The other end of diode D0 is connected to the 30th pin of single-chip U1, and the positive electrode of diode D5 is connected to the 31st pin of single-chip U1; in the start / stop switch, one end of the start / stop button switch S3 is grounded, and the other end is connected to one end of resistor R44, and is also connected to the 1st pin of single-chip U1 in MCU, and the other end of resistor R44 is connected to 5V DC voltage; in the AD acquisition input, the 15th pin of AD conversion chip U3 is connected to 5V DC voltage, and is also connected to one end of capacitor C8, and the other end of capacitor C8 is grounded, and the 8th pin and the 1st pin of AD conversion chip U3 are connected to the 15th pin of AD conversion chip U3. The 10th and 11th pins and the 16th pin are all grounded, the 5th pin of the AD conversion chip U3 is connected in series with the resistor R11 and then connected to a 5V DC voltage, the two ends of the crystal oscillator Y7 are respectively connected to one end of the capacitors C6 and C7, and are simultaneously connected to the 3rd and 2nd pins of the AD conversion chip U3, the other ends of the capacitors C6 and C7 are both grounded, the 4th pin of the low-power voltage reference chip U4 is grounded, the 8th pin of the low-power voltage reference chip U4 is connected to one end of the resistor R47, and is simultaneously connected to the 9th pin of the AD conversion chip U3, and the other end of the resistor R47 is connected to a 5V DC voltage;Between the AD acquisition input and the MCU, the 1st, 4th, 14th and 13th pins of the AD conversion chip U3 are connected to the 34th to 37th pins of the microcontroller through a 4-wire SPI bus. In the shaping filter input, in the precision rectifier circuit, the 4th pins of the op amp chips U5 and U6 are connected to a -9V DC voltage, the 7th pins of the op amp chips U5 and U6 are connected to a 9V DC voltage, the 3rd pin of the op amp chip U5 is connected to one end of the resistor R16 and one end of the capacitor C11, and the other end of the capacitor C11 is grounded, the 3rd pin of the op amp chip U6 is connected to one end of the resistor R21 and one end of the capacitor C16, and the other end of the capacitor C16 is grounded. In the filter circuit, one end of the resistors R12 and R13 are connected to a bidirectional TVS diode respectively. One end of the bidirectional TVS diode D8 and D10, the other end of the resistor R12 is connected to one end of the resistor R14 and one end of the capacitor C9, the other end of the resistor R13 is connected to one end of the resistor R15 and one end of the capacitor C10, the other end of the resistor R14 is connected to the other end of the capacitor C9 and the other end of the bidirectional TVS diode D8, and grounded, the other end of the resistor R15 is connected to the other end of the capacitor C10 and the other end of the bidirectional TVS diode D10, and grounded, between the filtering circuit and the precision rectifier circuit, one end of the bidirectional TVS diode D8 and the bidirectional TVS diode D10 are connected to the 6th pin of the operational amplifier chip U5 and U6 respectively; between the shaping filter input and the AD acquisition input, one end of the capacitor C9 and C10 are connected to the AD conversion chip The 6th and 7th pins of chip U3; in the resistance sampling input, after the high-voltage resistors R48~R52 are connected in series, one end is connected to one end of the high-voltage resistor R28 and the high-voltage wiring terminal P1, and the other end is connected to one end of the precision resistor R35, the other end of the precision resistor R35 is grounded, one end of the precision resistor R36 is connected to one end of the precision resistor R37, and the other end of the precision resistor R37 is grounded; between the resistance sampling input and the shaping filter input, one end of the precision resistor R35 is connected to the other end of the resistor R16, and the other end of the precision resistor R36 is connected to the other end of the resistor R21; between the high-voltage wiring L end and the resistance sampling input, the other end of the high-voltage resistor R28 is connected to the L end hole-type terminal P2; between the low-voltage wiring E end and the resistance sampling input, E The end hole type terminal P5 is connected to the other end of the precision resistor R36; within the relay switching sampling range, the first pin of the relay K1 is connected to the 5V DC voltage and is simultaneously connected to the cathode of the diode D6, the anode of the diode D6 is connected to the collector of the transistor Q3, and is simultaneously connected to the tenth pin of the relay K1, the emitter of the transistor Q3 is grounded, and the base of the transistor Q3 is connected to one end of the resistor R27; between the relay switching sampling range and the resistance sampling input, the eighth and ninth pins of the relay K1 are both connected to the other end of the precision resistor R37, and the seventh pin of the relay K1 is connected to one end of the precision resistor R36; between the relay switching sampling range and the MCU, the other end of the resistor R27 is connected to the 33rd pin of the microcontroller U1;In the relay switching high-voltage output, the first pin of the high-voltage module U8 is connected to a 9V DC voltage and is simultaneously connected to the normally closed contact of the relay K2. The common end of the contact of the relay K2 is connected to the wiring terminal P4 in the charging interface circuit. One end of the coil of the relay K2 is connected to a 5V DC voltage, and the other end is connected to the collector of the transistor Q5. The emitter of the transistor Q5 is grounded, and the base of the transistor Q5 is connected to one end of the resistor R42. Between the relay switching high-voltage output and the resistor sampling input, the high-voltage wiring terminal P1 is connected to the 6th pin of the high-voltage module U8. Between the relay switching high-voltage output and the MCU, the other end of the resistor R42 is connected to the 32nd pin of the single-chip computer U1. In the buzzer circuit, the positive pole of the buzzer LS1 is connected to a 5V DC voltage, and the negative pole is connected to the collector of the transistor Q4 and the negative pole of the light-emitting diode D7. The positive pole of the light-emitting diode D7 is connected to one end of the resistor R43, and the other end of the resistor R43 is connected to a 5V DC voltage. The emitter of transistor Q4 is grounded, and the base of transistor Q4 is connected to one end of resistor R26; between the buzzer circuit and MCU, the other end of resistor R26 is connected to pin 39 of single-chip U1; in the alarm gear selection, the third pin of alarm setting toggle switch S2 is grounded, the first, second, fourth and fifth pins of alarm setting toggle switch S2 are respectively connected to one end of resistors R38~R41, and respectively connected to pins 44~41 of single-chip U1 in MCU, and the other ends of resistors R38~R41 are connected to 5V DC voltage; in the LCM interface, the first, second, 18th and 20th pins of liquid crystal interface J2 are grounded, and the third and 19th pins of liquid crystal interface J2 are connected to 5V DC voltage; between the LCM interface and MCU, the fifth to eighth and tenth to 17th pins of liquid crystal interface J2 are respectively connected to the tenth to 13th and the eighteenth to 25th pins of single-chip U1. ;

[0010] In the MCU described in the present invention, the model of the single-chip microcomputer U1 is STC12C5A60S2-LQFP44; in the AD acquisition input, the model of the AD conversion chip U3 is AD7705, and the model of the low-power voltage reference chip U4 is LM285-2.5; in the shaping filter input, the models of the operational amplifier chips U5 and U6 are both OP07, and the models of the bidirectional TVS diodes D8 and D10 are both SMBJ5.0CA; in the relay switching sampling range, the model of the relay K1 is TQ2-5V, the model of the diode D6 is 1N4148, and the model of the transistor Q3 is S9013 NPN J3; in the relay switching high-voltage output, the model of the relay K2 is JQC-32F5-Z, and the model of the transistor Q5 is S9013 NPN J3; in the buzzer circuit, the model of the transistor Q4 is S9013 NPN J3; in the LCM interface, the LCD display module plugged into the liquid crystal interface J2 has a model of 12864 T6963; in the one-button power on / off circuit, the models of diodes D4 and D5 are both 1N4148, and the model of transistor Q1 is S9013 NPN J3; in the step-down and power supply circuit, the model of DC / DC converter control circuit U2 is MC34063, the model of diode D3 is 1N5819, the model of power module U7 is A0509S-2WR2, and the models of tantalum capacitors C21 and C22 are both type A 1UF35V.

[0011] The rechargeable battery in the charging interface circuit of the present invention is a lithium battery.

[0012] The electrode of the present invention is composed of a conductive soft electrode at a line end L, a conductive soft electrode at a ground end E, an insulating shell, a plug at the line end L, and a plug at the ground end E. The conductive soft electrode at the line end L and the conductive soft electrode at the ground end E are longitudinally and parallelly arranged at the upper end of the insulating shell at a certain distance, and the plug at the line end L and the plug at the ground end E are parallelly arranged at the lower end of the insulating shell at a certain distance, and are respectively connected to the conductive soft electrode at the line end L and the conductive soft electrode at the ground end E inside the insulating shell. The conductive soft electrode at the line end L and the conductive soft electrode at the ground end E have the same structure, both of which are V-shaped block structures with right-angle or oblique opening shapes.

[0013] The conductive soft electrode at the line end L and the conductive soft electrode at the ground end E described in the present invention are both conductive sponges formed by sponges wrapped with conductive cloth.

[0014] The advantages of the present invention are: 1) the insulation resistance tester of the safety tool is small in size, good in safety, and high in measurement accuracy. It contains a high-precision micro-current measurement system and a digital boost system. Only one person can hold the tester to measure the insulation resistance of the insulating rod. The measurement is performed automatically, and the measurement result is displayed on a large-screen liquid crystal display; 2) the electrode of the insulation resistance tester adopts a semi-encircling structure, which increases the measurement contact surface of the electrode, can realize continuous sliding test of the insulating rod without damaging the surface of the insulating rod, and the test can completely cover the surface of the insulating rod, so the overall resistance of the insulating rod can be conveniently tested, and the test value is displayed in real time and can be set Alarm range: the equipment can be tested when it is turned on, and the insulation resistance value will be displayed. If it exceeds the set alarm range, an alarm prompt will be given; 3) The alarm range setting value can be adjusted. The over-limit alarm value of the insulation resistance can be set to 700MΩ for traction substations and 100MΩ for contact networks. The over-limit alarm value of the overall resistance of the insulating rod is set to 10000MΩ; 4) The full Chinese operation interface is easy to operate; the output current is large, and the short-circuit current is ≥1mA; the anti-interference ability is strong, and the substation and contact network professionals can operate on-site, and the test will be automatically discharged; a rechargeable battery and charger are included, and it can be used continuously for 6 to 12 hours when fully charged. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the main structure of the electrode pin wiring of the tester of the present invention;

[0016] Figure 2 It is a left-side structural schematic diagram of the electrode pin wiring of the tester of the present invention;

[0017] Figure 3 It is a schematic diagram of the top view structure of the electrode of the tester of the present invention;

[0018] Figure 4 It is a schematic diagram of the electrode structure of the tester of the present invention when viewed from above;

[0019] Figure 5 yes Figure 4 Left view of

[0020] Figure 6 It is the overall circuit block diagram of the present invention;

[0021] Figure 7 It is the circuit schematic diagram of MCU1, buzzer circuit 9 and LCM interface 13 on the main board, as well as the start / stop switch 11 and alarm gear selection 12 on the control board;

[0022] Figure 8 It is the circuit schematic diagram of the step-down and power supply circuit 15 on the control board;

[0023] Fig. 9It is a circuit schematic diagram of the relay switching high voltage output 6, the power switch 10, the one-button switch circuit 14 and the charging interface circuit 16 on the control board;

[0024] Fig.10 This is the AD acquisition input 2 circuit schematic on the mainboard;

[0025] Fig.11 It is the circuit schematic diagram of the shaping filter input 3, the resistor sampling input 4, the relay switching sampling range 5, the high voltage wiring L terminal 7 and the low voltage wiring E terminal 8 on the main board.

[0026] In the figure: 23. Insulating rod under test. DETAILED DESCRIPTION

[0027] like Figure 1-11As shown, the safety tool insulation resistance tester includes a handheld host housing 18, a working circuit board, a charger and an electrode 17. A liquid crystal screen observation window 19 is provided at the upper front position of the handheld host housing 18. The working circuit board is installed in the handheld host housing 18. The electrode 17 is a semi-encircling structure, which includes a line end L-end plug 27 and a ground end E-end plug 28; the working circuit board includes a main board and a control board. The main board consists of an MCU1, an AD acquisition input 2, a shaping filter input 3, a resistance sampling input 4, a relay switching sampling range 5, a high-voltage wiring L end 7, a low-voltage wiring E end 8, a buzzer circuit 9 and an LCM interface 13. Among them, the high-voltage wiring L end 7 has an L-end hole-type terminal P2, and the low-voltage wiring E end 8 has a L-end hole-type terminal P2. The E-end hole-type terminal P5 is provided in the crimped wire E-end 8, and the control board is composed of a relay switching high-voltage output 6, a power switch 10, a start / stop switch 11, an alarm gear selection 12, a one-button power on / off circuit 14, a step-down and power supply circuit 15, and a charging interface circuit 16. Among them, the power switch 10 has a power button switch S1, the start / stop switch 11 has a start / stop button switch S3, and the alarm gear selection 12 has an alarm setting toggle switch S2. The main board and the control board are connected by connecting wires through reserved welding holes; the MCU1 is used to control the detection of powering on and off the tester, as well as the detection of starting and stopping the test, controlling the selection input of the alarm gear and setting the over-limit alarm value, and controlling the buzzer sounding and stopping, and the relay status The switching controls the reception of the sampled data, and displays the insulation resistance value of the tested insulating rod on the LCD screen of the LCD display module through internal calculation processing; the AD acquisition input 2 is used to convert the 2-way analog voltage signal after rectification and filtering by the shaping filter input 3 into a digital signal, and transmit it to the single-chip microcomputer in MCU1 through the SPI communication mode; the shaping filter input 3 is used to precisely rectify and filter the 2-way analog voltage signal collected by the resistance sampling input 4, and then transmit it to the AD acquisition input 2; the resistance sampling input 4 is used to collect the analog voltage signal of the high-voltage wiring L terminal 7 and the analog current signal of the low-voltage wiring E terminal 8, and convert them into 2-way analog voltage signals after resistance voltage division, and input them to the shaping filter input 3, so as to be transmitted to the single-chip microcomputer in MCU1 through the resistance voltage division method. The single-chip microcomputer in U1 calculates the insulation resistance of the insulating rod being tested; the relay switching sampling range 5 is used to judge the size of the sampled current and use the relay to switch the gear range, thereby expanding the test range; the high-voltage wiring L terminal 7 is used to connect the line end L terminal plug 27 of the electrode 17; the low-voltage wiring E terminal 8 is used to connect the ground end E terminal plug 28 of the electrode 17; the buzzer circuit 9 is used to stop the buzzer, and when the test result exceeds the warning value, the buzzer sounds an alarm; the LCM interface 13 is used to connect the LCD liquid crystal display module, control the reset, backlight and data output of the LCD liquid crystal display module, and display the test items and test data of the tester; the relay switching high-voltage output 6 is used to control the high-voltage module to output high voltage through the relay;The power switch 10 is used to turn on or off the tester; the start / stop switch 11 is used to start or stop the test of the tester; the alarm gear selection 12 is used to set the alarm gear signal and input the set alarm gear signal into the single-chip microcomputer in MCU1, and the single-chip microcomputer in MCU1 processes it internally to set the over-limit alarm value; the one-key power on / off circuit 14 is used to provide the power supply voltage V+ and is connected to the single-chip microcomputer in MCU1, and the single-chip microcomputer in MCU1 controls the detection of the state of the power switch 10; the step-down and power supply circuit 15 is used to reduce the power supply voltage V+ to the system working voltage, and provide the system with 5V DC voltage, -9V DC voltage and 9V DC voltage; the charging interface circuit 1 6 is used for charging the rechargeable battery inside it with an external charger, connecting the relay switching high-voltage output 6 to power the relay contact common end in the relay switching high-voltage output 6, and connecting the one-key switch circuit 14 so as to provide the power supply voltage V+ through the one-key switch circuit 14; the upper end position of the handheld host housing 18 is provided with an extension hole for the L-end hole-type terminal P2 and an extension hole for the E-end hole-type terminal P5, the front middle and lower positions of the handheld host housing 18 are provided with a first button 21 exposure hole for the power button switch S1 and a second button 20 exposure hole for the start / stop button switch S3, and the lower end position of the handheld host housing 18 is provided with an operating handle 22 exposure port for the alarm setting toggle switch S2. ;

[0028] like Figure 6-11As shown, the MCU1 includes a single-chip microcomputer U1, a power filter capacitor C3, a crystal oscillator circuit, a power-on reset circuit, a program download circuit, and resistors R45 and R46; the crystal oscillator circuit includes a crystal oscillator Y1 and capacitors C1 and C2; the power-on reset circuit includes a resistor R3 and a capacitor C4; the program download circuit includes a 4-wire single-row pin interface J1, resistors R1 and R2, and light-emitting diodes D1 and D2; the AD acquisition input 2 includes an AD conversion chip U3, a low-power voltage reference chip U4, a crystal oscillator Y7, capacitors C6-C8, and resistors R11 and R47; The shaping filter input 3 includes a precision rectifier circuit and a filter circuit. The precision rectifier circuit includes operational amplifier chips U5 and U6, resistors R16 and R21, and capacitors C11 and C16. The filter circuit includes resistors R12 to R15, capacitors C9 and C10, and bidirectional TVS diodes D8 and D10. The resistor sampling input 4 includes high-voltage resistors R28 and R48 to R52, high-voltage terminal P1, and precision resistors R35 to R37. The relay switching sampling range 5 includes relay K1, diode D6, transistor Q3, and resistor R27. The relay The switch high-voltage output 6 contains a high-voltage module U8, a relay K2, a transistor Q5 and a resistor R42; the high-voltage wiring L terminal 7 contains an L-terminal hole-type terminal P2; the low-voltage wiring E terminal 8 contains an E-terminal hole-type terminal P5; the buzzer circuit 9 contains a buzzer LS1, a transistor Q4, a light-emitting diode D7 and resistors R26 and R43; the power switch 10 contains a power button switch S1; the start / stop switch 11 contains a start / stop button switch S3 and a resistor R44; the alarm gear selection 12 contains an alarm setting toggle switch S2 and resistors R38~R41; The LCM interface 13 includes a liquid crystal interface J2, and an LCD display module is plugged into the liquid crystal interface J2; the one-button switch circuit 14 includes resistors R7-R10, diodes D4 and D5, and transistors Q1 and Q2; the step-down and power supply circuit 15 includes a DC / DC converter control circuit U2, resistors R4-R6, electrolytic capacitors CT1 and CT2, capacitor C5, diode D3, inductor L0, power supply module U7, and tantalum capacitors C21 and C22; the charging interface circuit 16 includes a charging interface J0, wiring terminals P3 and P4, and a rechargeable battery;

[0029] The connection relationship is as follows: in the charging interface circuit 16, the second pin of the charging interface J0 is connected to the wiring terminal P3 and grounded, the first pin of the charging interface J0 is connected to the wiring terminal P4, the negative electrode and the positive electrode of the rechargeable battery are connected to the wiring terminals P3 and P4 respectively, and the charging interface J0 is connected to an external charger for charging the rechargeable battery; in the one-key switch circuit 14, one end of the resistor R7 is connected to the emitter of the transistor Q2 and the wiring terminal P4 in the charging interface circuit 16, the other end of the resistor R7 is connected to the base of the transistor Q2 and one end of the resistor R8, and the collector of the transistor Q2 is connected to the collector of the transistor Q2. The power supply voltage V+ is output, the other end of the resistor R8 is connected to the anode of the diode D4 and the collector of the transistor Q1, the emitter of the transistor Q1 is grounded, the base of the transistor Q1 is connected to one end of the resistors R9 and R10, the other end of the resistor R9 is grounded, the cathodes of the diodes D4 and D5 are connected to one end of the power button switch S1 in the power switch 10, and the other end of the power button switch S1 is grounded; in the step-down and power supply circuit 15, the 6th and 4th pins of the DC / DC converter control circuit U2 are connected to the power supply voltage V+ and ground respectively, and the 1st 1. The 7th and 8th pins are connected to one end of the resistor R4, the other end of the resistor R4 is connected to the power supply voltage V+, and at the same time connected to the positive electrode of the electrolytic capacitor CT1, the negative electrode of the electrolytic capacitor CT1 is grounded, the 2nd pin of the DC / DC converter control circuit U2 is connected to the negative electrode of the diode D3, and at the same time connected to one end of the inductor L0, the positive electrode of the diode D3 is grounded, the other end of the inductor L0 is connected to the positive electrode of the electrolytic capacitor CT2 and one end of the resistor R5, and at the same time outputs a 5V DC voltage, the negative electrode of the electrolytic capacitor CT2 is grounded, the other end of the resistor R5 is connected to one end of the resistor R6, and at the same time The 5th pin of the DC / DC converter control circuit U2 is connected, the other end of the resistor R6 is grounded, the 3rd pin of the DC / DC converter control circuit U2 is connected to one end of the capacitor C5, the other end of the capacitor C5 is grounded, the 1st pin of the power module U7 is connected to a 5V DC voltage, the 2nd and 5th pins of the power module U7 are grounded, the 4th and 6th pins of the power module U7 output a -9V DC voltage and a 9V DC voltage respectively, the negative electrode of the tantalum capacitor C21 is connected to the -9V DC voltage, the positive electrode is connected to the negative electrode of the tantalum capacitor C22 and is grounded, and the positive electrode of the tantalum capacitor C22 is connected to the 9V DC voltage;In MCU1, the 38th pin of the single-chip microcomputer U1 is connected to a 5V DC voltage, the 16th pin of the single-chip microcomputer U1 is grounded GND, between the crystal oscillator circuit and the single-chip microcomputer U1, the two ends of the crystal oscillator Y1 are connected to the 15th and 14th pins of the single-chip microcomputer U1 respectively, between the power-on reset circuit and the single-chip microcomputer U1, one end of the capacitor C4 is connected to a 5V DC voltage, and the other end is connected to the 4th pin of the single-chip microcomputer U1, in the program download circuit, the 1st and 2nd pins of the 4-wire single-row pin interface J1 are connected to a 5V DC voltage and ground respectively, and one end of the resistors R1 and R2 are connected to the 4-wire single-row pin interface J1 respectively The 3rd and 4th pins of the 4-wire single-row pin interface J1 are connected to the 7th and 5th pins of the MCU U1 respectively, and the other ends of the resistors R1 and R2 are connected to the cathodes of the light-emitting diodes D1 and D2 respectively. The anodes of the light-emitting diodes D1 and D2 are connected to a 5V DC voltage. Between the program download circuit and the single-chip microcomputer U1, the 3rd and 4th pins of the 4-wire single-row pin interface J1 are connected to the 7th and 5th pins of the MCU U1 respectively. One end of the resistor R45 is connected to the power supply voltage V+, and the other end is connected to one end of the resistor R46, and is also connected to the 40th pin of the MCU U1. The other end of the resistor R46 is grounded; between the one-button switch circuit 14 and MCU1, the resistor R1 The other end of diode D0 is connected to the 30th pin of single-chip U1, and the positive electrode of diode D5 is connected to the 31st pin of single-chip U1; in the start / stop switch 11, one end of the start / stop button switch S3 is grounded, and the other end is connected to one end of resistor R44, and is also connected to the 1st pin of single-chip U1 in MCU1, and the other end of resistor R44 is connected to 5V DC voltage; in AD acquisition input 2, pin 15 of AD conversion chip U3 is connected to 5V DC voltage, and is also connected to one end of capacitor C8, and the other end of capacitor C8 is grounded, and pin 8 of AD conversion chip U3 is connected to the 1st pin of single-chip U1 in MCU1. , the 10th and 11th pins and the 16th pin are all grounded, the 5th pin of the AD conversion chip U3 is connected in series with the resistor R11 and then connected to the 5V DC voltage, the two ends of the crystal oscillator Y7 are respectively connected to one end of the capacitors C6 and C7, and are also connected to the 3rd and 2nd pins of the AD conversion chip U3, the other ends of the capacitors C6 and C7 are both grounded, the 4th pin of the low-power voltage reference chip U4 is grounded, the 8th pin of the low-power voltage reference chip U4 is connected to one end of the resistor R47, and is also connected to the 9th pin of the AD conversion chip U3, and the other end of the resistor R47 is connected to the 5V DC voltage;Between AD acquisition input 2 and MCU1, the 1st, 4th, 14th and 13th pins of the AD conversion chip U3 are connected to the 34th to 37th pins of the microcontroller through a 4-wire SPI bus. In the shaping filter input 3, in the precision rectifier circuit, the 4th pins of the op amp chips U5 and U6 are connected to a -9V DC voltage, the 7th pins of the op amp chips U5 and U6 are connected to a 9V DC voltage, the 3rd pin of the op amp chip U5 is connected to one end of the resistor R16 and one end of the capacitor C11, and the other end of the capacitor C11 is grounded, the 3rd pin of the op amp chip U6 is connected to one end of the resistor R21 and one end of the capacitor C16, and the other end of the capacitor C16 is grounded. In the filter circuit, one end of the resistors R12 and R13 are connected to bidirectional TVS diodes respectively. One end of D8 and D10, the other end of resistor R12 is connected to one end of resistor R14 and one end of capacitor C9, the other end of resistor R13 is connected to one end of resistor R15 and one end of capacitor C10, the other end of resistor R14 is connected to the other end of capacitor C9 and the other end of bidirectional TVS diode D8, and grounded, the other end of resistor R15 is connected to the other end of capacitor C10 and the other end of bidirectional TVS diode D10, and grounded, between the filtering circuit and the precision rectifier circuit, one end of the bidirectional TVS diode D8 and the bidirectional TVS diode D10 are connected to the 6th pin of op amp chips U5 and U6 respectively; between the shaping filter input 3 and the AD acquisition input 2, one end of capacitors C9 and C10 are connected to the AD conversion chip U3 respectively. Pins 6 and 7; in the resistance sampling input 4, after the high-voltage resistors R48~R52 are connected in series, one end is connected to one end of the high-voltage resistor R28 and the high-voltage terminal P1, and the other end is connected to one end of the precision resistor R35, and the other end of the precision resistor R35 is grounded, one end of the precision resistor R36 is connected to one end of the precision resistor R37, and the other end of the precision resistor R37 is grounded; between the resistance sampling input 4 and the shaping filter input 3, one end of the precision resistor R35 is connected to the other end of the resistor R16, and the other end of the precision resistor R36 is connected to the other end of the resistor R21; between the high-voltage terminal L 7 and the resistance sampling input 4, the other end of the high-voltage resistor R28 is connected to the L-end hole-type terminal P2; between the low-voltage terminal E 8 and the resistance sampling input 4, the E end The hole-type terminal P5 is connected to the other end of the precision resistor R36; within the relay switching sampling range 5, the first pin of the relay K1 is connected to a 5V DC voltage and is simultaneously connected to the cathode of the diode D6, the anode of the diode D6 is connected to the collector of the transistor Q3, and is simultaneously connected to the tenth pin of the relay K1, the emitter of the transistor Q3 is grounded, and the base of the transistor Q3 is connected to one end of the resistor R27; between the relay switching sampling range 5 and the resistor sampling input 4, the 8th and 9th pins of the relay K1 are both connected to the other end of the precision resistor R37, and the 7th pin of the relay K1 is connected to one end of the precision resistor R36; between the relay switching sampling range 5 and MCU1, the other end of the resistor R27 is connected to the 33rd pin of the microcontroller U1;In the relay switching high-voltage output 6, the first pin of the high-voltage module U8 is connected to a 9V DC voltage and is simultaneously connected to the normally closed contact of the relay K2. The contact common end of the relay K2 is connected to the wiring terminal P4 in the charging interface circuit 16. One end of the coil of the relay K2 is connected to a 5V DC voltage, and the other end is connected to the collector of the transistor Q5. The emitter of the transistor Q5 is grounded, and the base of the transistor Q5 is connected to one end of the resistor R42; between the relay switching high-voltage output 6 and the resistor sampling input 4, the high-voltage wiring terminal P1 is connected to the 6th pin of the high-voltage module U8; between the relay switching high-voltage output 6 and the MCU1, the other end of the resistor R42 is connected to the 32nd pin of the microcontroller U1; in the buzzer circuit 9, the positive pole of the buzzer LS1 is connected to a 5V DC voltage, and the negative pole is connected to the collector of the transistor Q4 and the negative pole of the light-emitting diode D7. The positive pole of the light-emitting diode D7 is connected to one end of the resistor R43, and the other end of the resistor R43 is connected to a 5V DC voltage, the emitter of the transistor Q4 is grounded, and the base of the transistor Q4 is connected to one end of the resistor R26; between the buzzer circuit 9 and the MCU1, the other end of the resistor R26 is connected to the 39th pin of the single-chip computer U1; in the alarm gear selection 12, the 3rd pin of the alarm setting toggle switch S2 is grounded, the 1st, 2nd, 4th and 5th pins of the alarm setting toggle switch S2 are respectively connected to one end of the resistors R38~R41, and are respectively connected to the 44th~41st pins of the single-chip computer U1 in the MCU1, and the other ends of the resistors R38~R41 are all connected to a 5V DC voltage; in the LCM interface 13, the 1st, 2nd, 18th and 20th pins of the liquid crystal interface J2 are all grounded, and the 3rd and 19th pins of the liquid crystal interface J2 are all connected to a 5V DC voltage; between the LCM interface 13 and the MCU1, the 5th~8th and 10th~17th pins of the liquid crystal interface J2 are respectively connected to the 10th~13th and 18th~25th pins of the single-chip computer U1. ;

[0030] like Figure 6-11As shown, in the MCU1, the model of the single-chip microcomputer U1 is STC12C5A60S2-LQFP44; in the AD acquisition input 2, the model of the AD conversion chip U3 is AD7705, and the model of the low-power voltage reference chip U4 is LM285-2.5; in the shaping filter input 3, the models of the operational amplifier chips U5 and U6 are both OP07, and the models of the bidirectional TVS diodes D8 and D10 are both SMBJ5.0CA; in the relay switching sampling range 5, the model of the relay K1 is TQ2-5V, the model of the diode D6 is 1N4148, and the model of the transistor Q3 is S9013 NPN J3; in the relay switching high-voltage output 6, the model of the relay K2 is JQC-32F5-Z, and the model of the transistor Q5 is S9013 NPN J3; in the buzzer circuit 9, the model of the transistor Q4 is S9013NPN J3; in the LCM interface 13, the LCD display module plugged into the liquid crystal interface J2 is of model 12864 (T6963); in the one-button switch circuit 14, the diodes D4 and D5 are of model 1N4148, and the transistor Q1 is of model S9013 NPN J3; in the step-down and power supply circuit 15, the DC / DC converter control circuit U2 is of model MC34063, the diode D3 is of model 1N5819, the power module U7 is of model A0509S-2WR2, and the tantalum capacitors C21 and C22 are of model A 1UF35V. The rechargeable battery in the charging interface circuit 16 is a lithium battery.

[0031] like Figure 1-5 As shown, the electrode 17 is composed of a conductive soft electrode 24 at the line end L, a conductive soft electrode 25 at the ground end E, an insulating shell 26, a plug 27 at the line end L, and a plug 28 at the ground end E. The conductive soft electrode 24 at the line end L and the conductive soft electrode 25 at the ground end E are arranged longitudinally and parallelly at the upper end of the insulating shell 26 at a certain distance, and the plug 27 at the line end L and the plug 28 at the ground end E are arranged parallelly at the lower end of the insulating shell 26 at a certain distance, and are respectively connected to the conductive soft electrode 24 at the line end L and the conductive soft electrode 25 at the ground end E inside the insulating shell 26. The conductive soft electrode 24 at the line end L and the conductive soft electrode 25 at the ground end E have the same structure, both of which are V-shaped block structures with right-angle or oblique opening shapes. The conductive soft electrode 24 at the line end L and the conductive soft electrode 25 at the ground end E are both conductive sponges composed of sponges wrapped with conductive cloth.

[0032] The alarm range setting value of this safety tool insulation resistance tester can be adjusted. The over-limit alarm value of insulation resistance can be set to 700MΩ for traction substation and 100MΩ for contact network. The over-limit alarm value of the overall resistance of the insulating rod is set to 10000MΩ. The tester has four gears of "off", "contact network", "substation" and "overall" to choose from. Before testing the insulation resistance, you must first select the appropriate gear for alarm setting by toggling the operating handle of the alarm setting toggle switch S2 according to the actual situation of the insulation requirements. When the gear is selected as "off", the alert value is turned off. When the gear is selected as "contact network", the over-limit alarm value is 100M, when the gear is selected as "substation", the over-limit alarm value is 700M, and when the gear is selected as "overall", the over-limit alarm value is 10000M.

[0033] When testing the resistance of an insulating rod, the insulation resistance tester of the safety tool is used to plug the line end L end plug 27 of the electrode 17 into the L end hole type terminal P2 in the high voltage wiring L end 7, and the ground end E end plug 28 of the electrode 17 into the E end hole type terminal P5 in the low voltage wiring E end 8; then the handheld host housing 18 of the tester is held in the hand, and the line end L end conductive soft electrode 24 and the ground end E end conductive soft electrode 25 of the electrode 17 are brought into contact with the insulating rod 23 to be tested (such as Figure 1 , 2 Then press and hold the first button 21 of the power button switch S1 for more than one second, the tester will start, and after the "Welcome" interface appears on the LCD screen, release the button and the tester will enter the standby interface; during the test, press and hold the second button 20 of the start / stop button switch S3, the tester will start the test, test the insulation resistance of the tested insulating rod 23, and the LCD screen will display the insulation resistance value of the tested insulating rod 23 in real time. When the test result is greater than the set over-limit alarm value, the LCD screen will immediately display "R> set over-limit alarm value" (for example, if the alarm setting selection gear is "overall", the over-limit alarm value is 10000 M, then the LCD screen displays "R>10000M"), the tester stops automatically after testing for 60S and enters the standby interface, the standby interface displays the insulation resistance value of the tested insulating rod 23 again, when the test result is less than the set over-limit alarm value (that is, exceeds the warning value), the LCD screen displays the insulation resistance value of the tested insulating rod 23 and the "over-limit warning" prompt, and the buzzer sounds an alarm, the test is completed, release the second button 20 of the start / stop button switch S3, the tester stops the test and enters the standby interface; finally, press and hold the first button 21 of the power button switch S1 for more than one second again, after the "Please release the power" interface appears on the LCD screen, you can release the button and the tester will shut down.

Claims

1. A safety tool insulation resistance tester, comprising a handheld host housing (18), a working circuit board, a charger and electrodes (17), wherein a liquid crystal viewing window (19) is provided at the upper front portion of the handheld host housing (18), and the working circuit board is installed in the handheld host housing (18), wherein: The electrode (17) is a semi-encircled structure, which includes a line end L-end plug (27) and a ground end E-end plug (28); the working circuit board includes a main board and a control board, the main board is composed of an MCU (1), an AD acquisition input (2), a shaping filter input (3), a resistance sampling input (4), a relay switching sampling range (5), a high-voltage wiring L-end (7), a low-voltage wiring E-end (8), a buzzer circuit (9) and an LCM interface (13), wherein the high-voltage wiring L-end (7) has an L-end hole-type terminal P2, and the low-voltage wiring E-end (8) has an E-end hole-type terminal P5, and the control board is composed of a relay switching high-voltage output (6), a power switch (10), a start / stop switch (11), and an alarm gear selection (12). , a one-button power on / off circuit (14), a voltage reduction and power supply circuit (15) and a charging interface circuit (16), wherein the power switch (10) has a power button switch S1, the start / stop switch (11) has a start / stop button switch S3, the alarm gear selection (12) has an alarm setting toggle switch S2, and the main board and the control board are connected by connecting wires through reserved welding holes; the MCU (1) is used to control the detection of power on and off of the tester, as well as the detection of starting and stopping the test, control the selection input of the alarm gear and set the over-limit alarm value, control the sounding and stopping of the buzzer, the switching of the relay state, control the reception of the sampled data, and display the tested absolute value on the LCD screen of the LCD display module through internal calculation processing. The AD acquisition input (2) is used to convert the two-way analog voltage signals rectified and filtered by the shaping filter input (3) into digital signals and transmit them to the single chip computer in the MCU (1) through the SPI communication method; the shaping filter input (3) is used to precisely rectify and filter the two-way analog voltage signals collected by the resistor sampling input (4) and transmit them to the AD acquisition input (2); the resistor sampling input (4) is used to collect the analog voltage signal of the high-voltage wiring L terminal (7) and the analog current signal of the low-voltage wiring E terminal (8), and convert them into two-way analog voltage signals after resistor voltage division, and input them to the shaping filter input (3), so that the single chip computer in the MCU (1) can calculate the insulation resistance value of the tested insulating rod through the resistor voltage division method. The relay switching sampling range (5) is used to judge the current size of the sampling and use the relay to switch the gear range, thereby expanding the test range; the high-voltage wiring L terminal (7) is used to connect the line end L terminal plug (27) of the electrode (17); the low-voltage wiring E terminal (8) is used to connect the ground end E terminal plug (28) of the electrode (17); the buzzer circuit (9) is used to realize the buzzer sound stop, and when the test result exceeds the warning value, the buzzer sound alarm; the LCM interface (13) is used to connect the LCD liquid crystal display module, control the reset, backlight and data output of the LCD liquid crystal display module, and display the test items and test data of the tester; the relay switching high-voltage output (6) is used to control the high-voltage module to output high voltage through the relay;The power switch (10) is used to turn on or off the tester; the start / stop switch (11) is used to start or stop the test of the tester; the alarm gear selection (12) is used to set the alarm gear signal and input the set alarm gear signal into the single chip microcomputer in the MCU (1), and the single chip microcomputer in the MCU (1) processes it internally to set the over-limit alarm value; the one-key power on / off circuit (14) is used to provide a power supply voltage V+ and is connected to the single chip microcomputer in the MCU (1), and the single chip microcomputer in the MCU (1) controls the detection of the state of the power switch (10); the step-down and power supply circuit (15) is used to reduce the power supply voltage V+ to the system working voltage, and provide the system with a 5V DC voltage, a -9V DC voltage and a 9V DC voltage; the charging interface circuit (1 6) used for charging the rechargeable battery inside the handheld host housing with an external charger, connecting the relay switching high voltage output (6) to supply power to the relay contact common terminal in the relay switching high voltage output (6), and connecting the one-key switch circuit (14) so ​​as to provide a power supply voltage V+ through the one-key switch circuit (14); the upper end of the handheld host housing (18) is provided with an extension hole for the L-end hole-type terminal P2 and an extension hole for the E-end hole-type terminal P5, the front middle and lower parts of the handheld host housing (18) are provided with a first button (21) exposure hole for the power button switch S1 and a second button (20) exposure hole for the start / stop button switch S3, and the lower end of the handheld host housing (18) is provided with an operating handle (22) exposure port for the alarm setting toggle switch S2. ; 2. The safety tool insulation resistance tester according to claim 1 is characterized in that: The MCU (1) includes a single-chip microcomputer U1, a power filter capacitor C3, a crystal oscillator circuit, a power-on reset circuit, a program download circuit, and resistors R45 and R46. The crystal oscillator circuit includes a crystal oscillator Y1 and capacitors C1 and C2. The power-on reset circuit includes a resistor R3 and a capacitor C4. The program download circuit includes a 4-wire single-row pin interface J1, resistors R1 and R2, and light-emitting diodes D1 and D2. The AD acquisition input (2) includes an AD conversion chip U3, a low-power voltage reference chip U4, a crystal oscillator Y7, capacitors C6-C8, and resistors R11 and R47. The shaping filter input (3) includes a precision rectifier circuit and a filter circuit. The precision rectifier circuit includes op amp chips U5 and U6, resistors R16 and R21, and capacitors C11 and C16. The filter circuit includes resistors R12 to R15, capacitors C9 and C10, and bidirectional TVS diodes D8 and D10. The resistor sampling input (4) includes high-voltage resistors R28 and R48 to R52, high-voltage terminal P1, and precision resistors R35 to R37. The relay switching sampling range (5) includes relay K1, diode D6, transistor Q3, and resistor R27. The relay switching high-voltage output (6 ) contains a high-voltage module U8, a relay K2, a transistor Q5 and a resistor R42; the high-voltage wiring L terminal (7) contains an L-terminal hole-type terminal P2; the low-voltage wiring E terminal (8) contains an E-terminal hole-type terminal P5; the buzzer circuit (9) contains a buzzer LS1, a transistor Q4, a light-emitting diode D7 and resistors R26 and R43; the power switch (10) contains a power button switch S1; the start / stop switch (11) contains a start / stop button switch S3 and a resistor R44; the alarm gear selection (12) contains an alarm setting toggle switch S2 and resistors R38~R41; L The CM interface (13) includes a liquid crystal interface J2, and an LCD display module is plugged into the liquid crystal interface J2; the one-button switch circuit (14) includes resistors R7-R10, diodes D4 and D5, and transistors Q1 and Q2; the step-down and power supply circuit (15) includes a DC / DC converter control circuit U2, resistors R4-R6, electrolytic capacitors CT1 and CT2, capacitor C5, diode D3, inductor L0, power supply module U7, and tantalum capacitors C21 and C22; the charging interface circuit (16) includes a charging interface J0, wiring terminals P3 and P4, and a rechargeable battery; The connection relationship is as follows: in the charging interface circuit (16), the second pin of the charging interface J0 is connected to the wiring terminal P3 and grounded, the first pin of the charging interface J0 is connected to the wiring terminal P4, the negative electrode and the positive electrode of the rechargeable battery are connected to the wiring terminals P3 and P4 respectively, and the charging interface J0 is connected to an external charger for charging the rechargeable battery; in the one-key on / off circuit (14), one end of the resistor R7 is connected to the emitter of the transistor Q2 and the wiring terminal P4 in the charging interface circuit (16), the other end of the resistor R7 is connected to the base of the transistor Q2 and one end of the resistor R8, and the base of the transistor Q2 is connected to the base of the transistor Q2. The collector outputs a power supply voltage V+, the other end of the resistor R8 is connected to the positive electrode of the diode D4 and the collector of the transistor Q1, the emitter of the transistor Q1 is grounded, the base of the transistor Q1 is connected to one end of the resistors R9 and R10, the other end of the resistor R9 is grounded, the cathodes of the diodes D4 and D5 are connected to one end of the power button switch S1 in the power switch (10), and the other end of the power button switch S1 is grounded; in the step-down and power supply circuit (15), the 6th and 4th pins of the DC / DC converter control circuit U2 are connected to the power supply voltage V+ and the ground respectively, and the DC / DC converter control circuit The 1st, 7th and 8th pins of the circuit U2 are all connected to one end of the resistor R4, the other end of the resistor R4 is connected to the power supply voltage V+, and is also connected to the positive electrode of the electrolytic capacitor CT1, the negative electrode of the electrolytic capacitor CT1 is grounded, the 2nd pin of the DC / DC converter control circuit U2 is connected to the negative electrode of the diode D3, and is also connected to one end of the inductor L0, the positive electrode of the diode D3 is grounded, the other end of the inductor L0 is connected to the positive electrode of the electrolytic capacitor CT2 and one end of the resistor R5, and outputs a 5V DC voltage at the same time, the negative electrode of the electrolytic capacitor CT2 is grounded, and the other end of the resistor R5 is connected to one end of the resistor R6, And at the same time, the 5th pin of the DC / DC converter control circuit U2 is connected, the other end of the resistor R6 is grounded, the 3rd pin of the DC / DC converter control circuit U2 is connected to one end of the capacitor C5, the other end of the capacitor C5 is grounded, the 1st pin of the power module U7 is connected to a 5V DC voltage, the 2nd and 5th pins of the power module U7 are grounded, the 4th and 6th pins of the power module U7 output a -9V DC voltage and a 9V DC voltage respectively, the negative electrode of the tantalum capacitor C21 is connected to the -9V DC voltage, the positive electrode is connected to the negative electrode of the tantalum capacitor C22 and grounded, and the positive electrode of the tantalum capacitor C22 is connected to the 9V DC voltage;In MCU (1), the 38th pin of the single-chip microcomputer U1 is connected to the 5V DC voltage, the 16th pin of the single-chip microcomputer U1 is connected to the ground GND, between the crystal oscillator circuit and the single-chip microcomputer U1, the two ends of the crystal oscillator Y1 are connected to the 15th and 14th pins of the single-chip microcomputer U1 respectively, between the power-on reset circuit and the single-chip microcomputer U1, one end of the capacitor C4 is connected to the 5V DC voltage, and the other end is connected to the 4th pin of the single-chip microcomputer U1, in the program download circuit, the 1st and 2nd pins of the 4-wire single-row pin interface J1 are connected to the 5V DC voltage and the ground respectively, and one end of the resistors R1 and R2 are connected to the The 3rd and 4th pins, and the other ends of resistors R1 and R2 are connected to the cathodes of light-emitting diodes D1 and D2 respectively, and the anodes of light-emitting diodes D1 and D2 are connected to a 5V DC voltage. Between the program download circuit and the single-chip microcomputer U1, the 3rd and 4th pins of the 4-wire single-row pin interface J1 are connected to the 7th and 5th pins of the single-chip microcomputer U1 respectively. One end of resistor R45 is connected to the power supply voltage V+, and the other end is connected to one end of resistor R46 and is also connected to pin 40 of the single-chip microcomputer U1. The other end of resistor R46 is grounded. Between the one-button power on / off circuit (14) and the MCU (1), resistor R1 The other end of diode D0 is connected to pin 30 of microcontroller U1, and the anode of diode D5 is connected to pin 31 of microcontroller U1; in the start / stop switch (11), one end of start / stop button switch S3 is grounded, and the other end is connected to one end of resistor R44, and is also connected to pin 1 of microcontroller U1 in MCU (1), and the other end of resistor R44 is connected to 5V DC voltage; in the AD acquisition input (2), pin 15 of AD conversion chip U3 is connected to 5V DC voltage, and is also connected to one end of capacitor C8, and the other end of capacitor C8 is grounded, and the pin 15 of AD conversion chip U3 is connected to 5V DC voltage. The 8th pin, the 10th pin, the 11th pin and the 16th pin are all grounded, the 5th pin of the AD conversion chip U3 is connected in series with the resistor R11 and then connected to the 5V DC voltage, the two ends of the crystal oscillator Y7 are respectively connected to one end of the capacitors C6 and C7, and are simultaneously connected to the 3rd and 2nd pins of the AD conversion chip U3, the other ends of the capacitors C6 and C7 are both grounded, the 4th pin of the low-power voltage reference chip U4 is grounded, the 8th pin of the low-power voltage reference chip U4 is connected to one end of the resistor R47, and is simultaneously connected to the 9th pin of the AD conversion chip U3, and the other end of the resistor R47 is connected to the 5V DC voltage;Between the AD acquisition input (2) and the MCU (1), the 1st, 4th, 14th and 13th pins of the AD conversion chip U3 are connected to the 34th to 37th pins of the microcontroller through the 4-wire SPI bus. In the shaping filter input (3), in the precision rectifier circuit, the 4th pins of the operational amplifier chips U5 and U6 are connected to a -9V DC voltage, the 7th pins of the operational amplifier chips U5 and U6 are connected to a 9V DC voltage, the 3rd pin of the operational amplifier chip U5 is connected to one end of the resistor R16 and one end of the capacitor C11, and the other end of the capacitor C11 is grounded, the 3rd pin of the operational amplifier chip U6 is connected to one end of the resistor R21 and one end of the capacitor C16, and the other end of the capacitor C16 is grounded. In the filter circuit, one end of the resistor R12 and one end of the resistor R13 are connected to Connect one end of the bidirectional TVS diodes D8 and D10, the other end of the resistor R12 is connected to one end of the resistor R14 and one end of the capacitor C9, the other end of the resistor R13 is connected to one end of the resistor R15 and one end of the capacitor C10, the other end of the resistor R14 is connected to the other end of the capacitor C9 and the other end of the bidirectional TVS diode D8, and grounded, the other end of the resistor R15 is connected to the other end of the capacitor C10 and the other end of the bidirectional TVS diode D10, and grounded, between the filter circuit and the precision rectifier circuit, one end of the bidirectional TVS diode D8 and the bidirectional TVS diode D10 are connected to the 6th pin of the operational amplifier chip U5 and U6 respectively; between the shaping filter input (3) and the AD acquisition input (2), the capacitors C9 and C10 One end is connected to the 6th and 7th pins of the AD conversion chip U3 respectively; in the resistor sampling input (4), after the high-voltage resistors R48 to R52 are connected in series, one end is connected to one end of the high-voltage resistor R28 and the high-voltage wiring terminal P1, and the other end is connected to one end of the precision resistor R35, the other end of the precision resistor R35 is grounded, one end of the precision resistor R36 is connected to one end of the precision resistor R37, and the other end of the precision resistor R37 is grounded; between the resistor sampling input (4) and the shaping filter input (3), one end of the precision resistor R35 is connected to the other end of the resistor R16, and the other end of the precision resistor R36 is connected to the other end of the resistor R21; between the high-voltage wiring L terminal (7) and the resistor sampling input (4), the other end of the high-voltage resistor R28 is connected to L The terminal hole type terminal P2; between the low voltage wiring E terminal (8) and the resistance sampling input (4), the E terminal hole type terminal P5 is connected to the other end of the precision resistor R36; within the relay switching sampling range (5), the first pin of the relay K1 is connected to the 5V DC voltage and is also connected to the cathode of the diode D6, the anode of the diode D6 is connected to the collector of the transistor Q3, and is also connected to the tenth pin of the relay K1, the emitter of the transistor Q3 is grounded, and the base of the transistor Q3 is connected to one end of the resistor R27; between the relay switching sampling range (5) and the resistance sampling input (4), the 8th and 9th pins of the relay K1 are both connected to the other end of the precision resistor R37, and the 7th pin of the relay K1 is connected to one end of the precision resistor R36;The other end of the resistor R27 is connected between the relay switching sampling range (5) and the MCU (1), and the other end of the resistor R27 is connected to the 33rd pin of the single-chip computer U1; in the relay switching high-voltage output (6), the first pin of the high-voltage module U8 is connected to the 9V DC voltage and is also connected to the normally closed contact of the relay K2. The contact common end of the relay K2 is connected to the terminal P4 in the charging interface circuit (16). One end of the coil of the relay K2 is connected to the 5V DC voltage and the other end is connected to the collector of the transistor Q5. The emitter of the transistor Q5 is grounded. The base of transistor Q5 is connected to one end of resistor R42; the relay switches between the high voltage output (6) and the resistor sampling input (4), and the high voltage terminal P1 is connected to the 6th pin of the high voltage module U8; the relay switches between the high voltage output (6) and the MCU (1), and the other end of the resistor R42 is connected to the 32nd pin of the microcontroller U1; in the buzzer circuit (9), the positive electrode of the buzzer LS1 is connected to the 5V DC voltage, the negative electrode is connected to the collector of the transistor Q4, and the negative electrode of the light emitting diode D7, and the positive electrode of the light emitting diode D7 is connected to the voltage One end of resistor R43 is connected to the other end of resistor R43, and the other end of resistor R43 is connected to a 5V DC voltage. The emitter of transistor Q4 is grounded, and the base of transistor Q4 is connected to one end of resistor R26; between the buzzer circuit (9) and MCU (1), the other end of resistor R26 is connected to pin 39 of microcontroller U1; in the alarm gear selection (12), the third pin of alarm setting toggle switch S2 is grounded, and the first, second, fourth and fifth pins of alarm setting toggle switch S2 are respectively connected to one end of resistors R38 to R41, and are respectively connected to The 44th to 41st pins of the single-chip microcomputer U1 in the MCU (1) and the other ends of the resistors R38 to R41 are connected to a 5V DC voltage; in the LCM interface (13), the 1st, 2nd, 18th and 20th pins of the liquid crystal interface J2 are grounded, and the 3rd and 19th pins of the liquid crystal interface J2 are connected to a 5V DC voltage; between the LCM interface (13) and the MCU (1), the 5th to 8th pins and the 10th to 17th pins of the liquid crystal interface J2 are connected to the 10th to 13th pins and the 18th to 25th pins of the single-chip microcomputer U1 respectively. ; 3. The safety tool insulation resistance tester according to claim 2 is characterized in that: In the MCU (1), the model of the single chip microcomputer U1 is STC12C5A60S2-LQFP44; in the AD acquisition input (2), the model of the AD conversion chip U3 is AD7705, and the model of the low power consumption voltage reference chip U4 is LM285-2.5; in the shaping filter input (3), the model of the operational amplifier chips U5 and U6 are both OP07, and the model of the bidirectional TVS diodes D8 and D10 are both SMBJ5.0CA; in the relay switching sampling range (5), the model of the relay K1 is TQ2-5V, the model of the diode D6 is 1N4148, and the model of the transistor Q3 is S9013 NPN J3; in the relay switching high voltage output (6), the model of the relay K2 is JQC-32F5-Z, and the model of the transistor Q5 is S9013 NPN J3; in the buzzer circuit (9), the model of the transistor Q4 is S9013 NPN J3; in the LCM interface (13), the LCD display module plugged into the liquid crystal interface J2 has a model number of 12864 T6963; in the one-button on / off circuit (14), the models of the diodes D4 and D5 are both 1N4148, and the model of the transistor Q1 is S9013 NPN J3; in the step-down and power supply circuit (15), the model of the DC / DC converter control circuit U2 is MC34063, the model of the diode D3 is 1N5819, the model of the power module U7 is A0509S-2WR2, and the models of the tantalum capacitors C21 and C22 are both A-type 1UF35V.

4. The safety tool insulation resistance tester according to any one of claims 1 to 3, characterized in that: The rechargeable battery in the charging interface circuit (16) is a lithium battery.

5. The safety tool insulation resistance tester according to any one of claims 1 to 3, characterized in that: The electrode (17) is composed of a line end L-end conductive soft electrode (24), a ground end E-end conductive soft electrode (25), an insulating shell (26), a line end L-end plug (27), and a ground end E-end plug (28). The line end L-end conductive soft electrode (24) and the ground end E-end conductive soft electrode (25) are longitudinally and parallelly arranged at a certain distance on the upper end of the insulating shell (26), and the line end L-end plug (27) and the ground end E-end plug (28) are longitudinally and parallelly arranged at a certain distance on the lower end of the insulating shell (26), and are respectively connected to the line end L-end conductive soft electrode (24) and the ground end E-end conductive soft electrode (25) inside the insulating shell (26). The line end L-end conductive soft electrode (24) and the ground end E-end conductive soft electrode (25) have the same structure, both of which are V-shaped block structures with right-angle or oblique opening shapes.

6. The safety tool insulation resistance tester according to claim 5 is characterized in that: The line end L end conductive soft electrode (24) and the ground end E end conductive soft electrode (25) are both conductive sponges formed by sponges wrapped with conductive cloth.

Images