Viesturs, I had the same issue as you do with Plasma and THCAD. I contacted local Plasma source service guy, who advised me to take a signal from the source before high frequency generator. Another suggestion was to take cheapest multimeter, connect it to this point, while set at HV DC. If it survives - the voltages are not too high :)
Having his suggestions and block scheme I did this successfully. I connected my scope too. Then connected THCAD with resistors, placed at the plasma source. I used lowpass hal component too. Here is a part of .hal file and oscillograms: http://robotech.lt/?p=14 On 01/31/2015 11:59 AM, Viesturs Lācis wrote: > Hello! > > I have Jasic 100 A plasma source and Mesa THCAD card (extended to 310V > measuring range). The thing is that there is no dedicated output > signal in plasma source that would provide a feedback of plasma arc > voltage. > > I thought that I might connect THCAD inputs directly to plasma torch > and ground leads, but THCAD manual convinced me not to do so - it says > something about "touch-start plasma only", which does not seem to be > the case here. > > So far I have received 2 opposite suggestions: > 1) attach THCAD inputs to main transformer output _before_ rectifier > input - I was told that rectifier bridge will protect the board from > any HF (when arc is launched); > I would use very small and simple rectifier bridge (1000 V, 2A) to > make the signal from bipolar to unipolar and then try some HAL magic > to smooth out the fluctuations of the reading value; > 2) attach THC inputs _after_ rectifier input - I was told that main > transformer output frequency is in several kHz range and that would > bake my rectifier or some other electronics. > > I would appreciate any suggestions, where and how to attach THCAD > board to Jasic plasma source, which does not have dedicated output > signal for THC purpose. > > Viesturs > ------------------------------------------------------------------------------ Dive into the World of Parallel Programming. The Go Parallel Website, sponsored by Intel and developed in partnership with Slashdot Media, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials and more. Take a look and join the conversation now. http://goparallel.sourceforge.net/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
