Circuit path · WSM-315 sequence

WSM-315 gas, HF and current-feedback path

This path reference explains how a WSM-315 TIG welder coordinates torch input, gas solenoid, HF start, current command, inverter output, current feedback and HF cutoff. It helps diagnose cases where one part of the sequence works but the next does not.

Combined sequence path

Trigger input2T/4T or foot pedal contactor requests welding sequence.
Gas timingPre-flow and post-flow logic drives the gas solenoid.
HF startTimed HF command drives relay/transformer/discharge section.
Current commandPanel or pedal sets output current and pulse behavior.
Inverter driveControl board enables the main power stage.
Feedback/cutoffCurrent feedback confirms arc and helps stop HF after transfer.

Sequence failure interpretation

WorksDoes not workLikely boundary
Torch inputGas valveGas timing output, solenoid relay, solenoid coil or wiring.
Gas valveHF startHF enable command, HF relay, HF board supply or HV path.
HF startMain currentDrive enable, output stage, current command, work clamp or torch output path.
Main currentCurrent controlPanel pot, foot pedal command, feedback and control-loop path.
Main arcHF cutoffArc-detect / current-feedback / HF relay release path.
Gas outputPost-flow timingPanel timing command, timing circuit or gas relay release.

Useful cross-checks

Local vs remote

If panel current works but pedal does not, the fault is likely remote connector, pedal pot or remote selection path.

Gas vs HF

Gas action confirms trigger logic but not HF board health or main-output enable.

HF vs current

HF spark confirms ignition path but not inverter drive or output rectifier health.

Signal-path principle

In WSM-315 diagnosis, the most important question is not “which board is bad?” It is “which step of the sequence stopped?” That answer decides whether to inspect panel, control board, gas/HF board, feedback or power output.