Hi all. Newbie here, but love electronics. I work in the Heating and Cooling industry, and my point in this thread is based on the fact that we replace many Variable Frequency Drives. I have taken some apart, and feel confident in testing individual components, when off the PCB. The next step in my learning is to test them while integrated, which I would like to use a scope for. I am asking the forum what would be the specifications required for a new Oscilliscope purchase? I feel my goal is to be able to test the rectification circuit, the dc filtering circuit (IE caps), and the switching circuit (usually IGBTs). Below are my working conditions:
VFDS at 600 vac, 3 phase, so bus voltage at ~870 vdc.
IGBT's on VFD's fire between 5 khz and 15 khz (from my understanding). So would you guys have any suggestions as to what kind of Bandwidth, sampling rate, # channels, etc I would need? And would anyone like to suggest analog vs. digital vs. USB?
If the above is sufficient data for an opinion, feel free the disregard the following. As stated above, my goals will be to test the main three components that I feel comfortable to replace. If it were possible, I might like to be able to see the firing of the IGBT's at the gate, but I wouldn't be able to replace a single component that would affect the IGBT firing, mostly it's too complicated for me at this point, and really, if it's tied to the logic of the board, I wouldn't know what to do besides replace the board. Again, I feel limited at this time, just because I'm a newbie!
Further, would I be able to see any distortion, harmonics, current leakage through bearings? My hopes would be for a simple device that wouldn't be too expensive, but that would cover the minimal requirements are listed If I could get more for a small amount of cost increase, I would probably like to do so. I hope I have been clear, and I really appreciate any input you guys can give! Thanks for your time.
VFDS at 600 vac, 3 phase, so bus voltage at ~870 vdc.
IGBT's on VFD's fire between 5 khz and 15 khz (from my understanding). So would you guys have any suggestions as to what kind of Bandwidth, sampling rate, # channels, etc I would need? And would anyone like to suggest analog vs. digital vs. USB?
If the above is sufficient data for an opinion, feel free the disregard the following. As stated above, my goals will be to test the main three components that I feel comfortable to replace. If it were possible, I might like to be able to see the firing of the IGBT's at the gate, but I wouldn't be able to replace a single component that would affect the IGBT firing, mostly it's too complicated for me at this point, and really, if it's tied to the logic of the board, I wouldn't know what to do besides replace the board. Again, I feel limited at this time, just because I'm a newbie!
Further, would I be able to see any distortion, harmonics, current leakage through bearings? My hopes would be for a simple device that wouldn't be too expensive, but that would cover the minimal requirements are listed If I could get more for a small amount of cost increase, I would probably like to do so. I hope I have been clear, and I really appreciate any input you guys can give! Thanks for your time.