Circuit reference
TIG HF Arc-Start Sequence Reference
A general TIG high-frequency arc-start sequence reference for WSM, WSE, CT-312 and similar machines.
Quick Answer
The TIG HF arc-start sequence should be treated as a controlled event: torch input, gas pre-flow, HF command, HV generation, arc transfer and HF cutoff.
- HF hardware is only one layer; missing control command can also create no-HF symptoms.
- HF stuck on after arc transfer is a cutoff/control problem, not normal start behavior.
- Use this reference as a neutral circuit path for WSM, WSE, CT-312 and similar TIG machines.
TIG HF sequence evidence
| Sequence layer | Expected behavior | Failure pattern |
|---|---|---|
| Torch input | Starts the timing sequence. | No gas/HF/current if trigger input is missing. |
| Pre-flow gas | Gas opens before HF/current. | No gas or gas timing abnormal. |
| HF command | Control board commands HF only during start. | No HF if command missing; stuck HF if command does not end. |
| HV pack / relay | HF board generates start energy. | Command exists but no HF at torch. |
| Arc transfer | Main current takes over after arc starts. | HF may continue if transfer evidence missing. |
| HF cutoff | HF stops after transfer. | HF stuck on after arc start. |
Related records
Use symptom pages after this sequence reference.