Hello All -
Our Brother HS-350 EDM is working just fine at low energy (E-4) setting but wire break (in the upper part) happens immediately as we go to E=5 and above.
Appears to be some Discharge Control FET/Logic issue. We have checked discharge On/Off signal and FET trigger waveform using oscilloscope at E=4 and everything seems to be OK. At E=5 or above, we get strong unregulated arcing within microseconds and the wire break happens so suddenly that no time to check anything on oscilloscope. Settings are:
Spark Cycle = 20micro seconds
Spark Rate = 80 (denotes Duty Cycle)
Spark Energy = 4 (all OK)
On the discharge board, each energy level is a discrete 4bit data so finite changes happen on the board as more amperage being dialed in as we go from E=4 to E=5 and above. The MOSFETS check out OK - so likely a logic problem? in that no controlled discharge? The one quick glance at oscilloscope, the discharge pulse seemed to widen abnormally - but no definite proof of this yet.
We have thought about putting in a spool of Tungsten (W) or Moly Wire to see if wire survives long enough to get a decent oscilloscope trace - and open to any other ideas.
Any suggestions? Thanks - enkad
Our Brother HS-350 EDM is working just fine at low energy (E-4) setting but wire break (in the upper part) happens immediately as we go to E=5 and above.
Appears to be some Discharge Control FET/Logic issue. We have checked discharge On/Off signal and FET trigger waveform using oscilloscope at E=4 and everything seems to be OK. At E=5 or above, we get strong unregulated arcing within microseconds and the wire break happens so suddenly that no time to check anything on oscilloscope. Settings are:
Spark Cycle = 20micro seconds
Spark Rate = 80 (denotes Duty Cycle)
Spark Energy = 4 (all OK)
On the discharge board, each energy level is a discrete 4bit data so finite changes happen on the board as more amperage being dialed in as we go from E=4 to E=5 and above. The MOSFETS check out OK - so likely a logic problem? in that no controlled discharge? The one quick glance at oscilloscope, the discharge pulse seemed to widen abnormally - but no definite proof of this yet.
We have thought about putting in a spool of Tungsten (W) or Moly Wire to see if wire survives long enough to get a decent oscilloscope trace - and open to any other ideas.
Any suggestions? Thanks - enkad
