1Working principle of computer-controlled voltage breakdown tester

mains electricity→ Isolation regulator → Step up transformer（50 kV/1 kVA）→ Protection resistor → High voltage electrode

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Sample breakdown/Flashing → Current sampling resistor → Signal conditioning →A/D→MCU/Industrial PC

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Comparator action→ Solid state relay cuts off regulator → High voltage returns to zero → Discharge rod connected → Sound and light alarm

key points

1. The boost rate is determined byMCUControl the stepper motor to drive the sliding arm of the voltage regulator, achieving0.1–5 kV/sLinearly adjustable.

2. Breakdown discrimination: instantaneous current value ≥ set threshold (usually5–20 mACan be set) or voltage drop rate ≥20 %/20 ms.

3. Discharge circuit: High voltage relay+Water resistance/Power resistor（5 kΩ/100 W）+Discharge rod, ensure5 sResidual voltage inside<50 V.

4. All operation buttons are24 VLogic, isolated from the high-voltage side optoelectronics to ensure the computer/Personal safety.

2、 Panel 12 A button/Common faults and quick troubleshooting of instructions

1. Voltage display

Fault phenomenon: No display or value jump when powered on

Reason:① Header24 VThe power fuse is broken; ② High voltage divider100 MΩ resistor chain breaks due to moisture; ③ The shielding layer of the signal line is broken, causing spatial interference.

Solution: Replace 0.5 AGlass tube insurance; use2500 VMegohmmeter voltage divider to ground ≥500 MΩ, otherwise dry it+Silicone oil refilling; checkBNCShield the net and re crimp it.

2. switch lock

Fault phenomenon: Key turned toThe high voltage cannot be started even after being turned on

Reason:① Oxidation of micro switch contacts inside the lock; ② The key is worn out and not pressed in place.

Solution: Spray WD-40Rotate repeatedly afterwards10 Secondly; If it is still ineffective, replace the lock cylinder (model:D4F-102）.

3. Current Display

Fault phenomenon: No sample still displayed 0.05 mAAnd zeroing is ineffective

Reason:① Sampling resistor50 Ω/5 WWarm drift; ② Operational amplifier zero drift>2 mV.

Solution: Short circuit the high-voltage electrode, software executionZero drift calibration; Hardware replacement0.1 %Precision resistor and recalibrate.

4. Discharge alarm

Fault phenomenon: No alarm after breakdown

Reason:① Buzzer24 VLine detachment; ②MCUOutput port optocoupler breakdown.

Solution: The buzzer should be tested at both ends 24 VIf not available, check the line; If there is voltage but it still doesn't sound, replace the buzzer; ifMCUNo output from port → Replace optocouplerPC817.

5. Manual discharge

Fault phenomenon: The voltmeter does not decrease after pressing

Reason:① Contact erosion of discharge relay; ② The discharge resistor is open circuit.

Solution: Measure the contact resistance of the relay after power failure>1Replace Ω immediately（JQX-38F 30 A）； Measure discharge resistance5 kΩ±5 %If there is an open circuit, replace it with a wire wound resistor of the same specification.

6. fan switch

Fault phenomenon: The fan does not turn, no 220 Voutput

Reason:① Internal shrapnel fatigue of ship type switch; ② Fan capacitor1.5 µFinvalid.

Solution: Short circuit the switch to check if the fan is running. If it is running, replace the switch; Still not turning→ Replace the capacitor and measure the winding resistance (main winding ≈)180 Ω, secondary ≈220 of).

7. Control area (touch screen)

Fault phenomenon: No response or screen flickering when clicked

Reason:①24 VPower Ripple>200 mV② Touch screenUSBThe line is loose.

Solution: Oscilloscope measurement 24 Vplus470 µF/50 VElectrolytic filtering; ReinsertUSBSquare mouth, still ineffective → Replace7 Inch industrial touch screen（eGalaxDrive).

8. light switch

Fault phenomenon:LEDLight strip flicker

Reason:① Switching power supply12 VOutput missing filter; ② The grounding of the light strip and the introduction of pulses to the high voltage ground are common.

Solution: In 12 VOutput and220 µF/25 V+0.1 µFCeramics; Separate the lighting cable to the "clean" pile of the casing.

9. Door position indication

Fault phenomenon: The door remains red even after being closed

Reason:① OmronD4C-1202Wear of travel switch roller; ② The aging and insufficient compression of the door seal strip.

Solution: Adjust the switch bracket to press down the roller 1.5 mm; Replace10 mmThick silicone rubber sealing strip.

10. Zero point indication

Fault phenomenon: The high voltage has returned to zero, but the light still does not light up

Reason:① Low voltage arm of voltage divider10 kΩ resistance virtual soldering; ② ComparatorLM393Bad.

Solution: The output of the voltage divider should<40 mV(Corresponding to0.2 kV）If not available, repair welding; Still not flipping with voltage → ReplaceLM393And add at the same phase end20 mVDelay.

11. High voltage startup

Fault phenomenon: Immediately pop up a report after pressingThe door is not closed

Reason:①PLCinput portX2internal24 VOptocoupler short circuit, resulting in loss of normally closed signal; ② The door hook screw is loose, and the travel switch is instantly disconnected.

Solution: Monitoring PLCindicator lightX2It should be constantly on, if flashing, tighten the door hook;PLCIf the mouth is damaged, change the line to a vacant oneX6And replace the address within the ladder diagram.

12. High pressure stop (emergency stop)

Fault phenomenon: Unable to reset after shooting, high voltage is always prohibited

Reason:① The mushroom head comes with self-locking mechanism but has not been rotated out; ② Safety relay in emergency stop circuitPNOZManual reset is required.

Solution: Rotate clockwise to pull out the mushroom head; press PNOZUp Blue“Reset”If the key is still not engaged, check if the emergency stop series circuit is disconnected (door interlock, overcurrent, zero voltage).

3、 Maintenance checklist (recommended every time) 3 Execute once a month)

1. use2500 VThe megohmmeter is used to measure the insulation of high-voltage transformers, voltage dividers, and protective resistors to ground500 MOh.

2. Manual discharge10 Next, measure the residual voltage<50 V, Time<3 s.

3. Calibration voltage and current: using0.1 level50 kVVoltage divider and0.05 Comparison of milliampere meters, error>±1 %Adjust the software coefficient.

4. Check all24 VLogic fuse, emergency stop circuit, door interlock function.

5. Clean the porcelain bottles and oil stains inside the compartment of the step-up transformer to prevent creepage.