What Causes A Transmission Fault in The Ultrasonic Lace Machine's Generator?

1. Mold (Lace Welding Horn) Issues

(1) Mold cracking or hairline fractures: These may not be visible to the naked eye; however, vibration causes a sudden frequency shift, and the generator detects abnormal reflections, triggering a transmission fault alarm.
(2) Loose mold screws or debris in the threads: Dust or aluminum shavings on the contact surfaces (transducer–booster–mold) cause poor contact and energy reflection, triggering the protection system.
(3) Mold frequency shift: Wear or thermal deformation causes the actual resonant frequency to deviate from the generator's set frequency; the system fails to track the frequency, resulting in a transmission fault alarm.
Remedy: Remove the mold, clean the threads, and tighten securely; replace the mold immediately if cracks are found; perform a frequency scan after replacing the mold.

 

2. Transducer (Oscillator) Faults
(1) Piezoelectric ceramic elements aging, cracking, or delaminating; insulation degradation or impedance anomalies prevent the generator from driving the unit properly.
(2) Transducer exposed to moisture or water ingress; insulation failure or current leakage triggers a transmission fault alarm.
Symptoms: Alarm triggers even under no-load conditions; transducer overheats abnormally during operation.

 

3. Connection Cables (High-Frequency Aviation Connector Cables)
(1) Internal wire breakage, or loose/oxidized aviation connectors; signal transmission is interrupted, preventing the generator from receiving feedback and triggering a transmission fault alarm.
(2) Damaged cable insulation causing a short circuit to ground.
Test: Test using a high-frequency cable known to be in good condition.

 

4. Generator (Control Unit) Faults

(1) Poor heat dissipation: Fan failure or dust-clogged vents cause the power transistors to overheat and trigger protection, resulting in a transmission fault alarm.
(2) Power component failure: Aging or damage to IGBT power transistors, rectifier bridges, or resonant capacitors prevents high-frequency signal output.
(3) Main control board / Frequency tracking circuit failure: Damage to the automatic frequency tracking module prevents frequency locking, triggering a transmission fault alarm (loss-of-lock alarm).
(4) Unstable power input: Significant 220V voltage fluctuations or voltage levels that are too low/high cause abnormal generator operation; fuse blows.

 

Quick troubleshooting steps (Safety first: Disconnect power before proceeding)

1. No-load test (Crucial for diagnosis)
Remove the mold, leaving only the transducer and booster attached; power on and press the ultrasonic test button:
If a fault is still reported: The issue lies with the transducer, high-frequency cable, or generator unit.
If no fault is reported: The issue lies with the lace mold.

2. Inspect the high-frequency aviation connector cable; unplug and reconnect it, and clean any oxidation from the contacts. If possible, test with a replacement cable.
3. Inspect the threads on the transducer, booster, and mold; clean away aluminum shavings and dust, and ensure all components are securely tightened.
4. Clean the generator unit's cooling fan and dust filter; verify that the fan is spinning.
5. Reduce cylinder pressure and lower the power setting slightly before test-running; allow for intermittent cooling during prolonged operation.
6. If the alarm persists during the no-load test: The transducer or internal generator hardware is likely damaged. Professional inspection and repair are required; do not repeatedly force the unit to start, as this can burn out the generator's power transistors.