I'm building a MOSFET+LiPo battery driven multi stage coilgun as a hobby. My question is:
How much does MOSFET gate-> Driver circuit distance matter in my case?(very low frequency)
I've read many articles stating the importance of minimizing the distance to avoid stray capacitance/inductance. However these articles all focus on using MOSFETs for high frequency applications on tiny PCBs, where super fast switching times are paramount. In my case there is no real hurry from the coilguns point of view. The coils are "ON" for at least a millisecond at a time, followed by tens of ms of "OFF" time. So I've gone with the assumption that distance doesn't really concern me.
This was further encouraged by my first serious test setup where i had ~15cm between a gate driver mounted on a solderless breadboard and the MOSFET. The test went perfectly, it operated at ~10cycles/second (9ms ON, 91ms OFF) in 30cycle bursts, with no apparent trouble (no broken MOSFET). I lack the expertise and equipment to really measure things like turn on speed or such, so I have no idea if the MOSFET was operating well, or if a shorter better circuit would really pay off in the long run.
I would be fine with what i have, but the full-scale coilgun will be ~80cm long. If i place all the drive circuits on one board at the spot where i would want to have it, the longest distance would be ~60cm. Would this matter? I would prefer not placing individual gate drivers next to each mosfet (which must be under the coils due to space issues).
Thank you in advance!