Question regarding how missing capacitors will affect performance (Cyton V3)
Okay, so... I've had my Cyton V3 board for nearly eight years now (since 2015). I only used it during my undergrad and master thesis projects, and I had only begun tinkering with it again lately after getting into academics again.
I've been trying to handle it carefully, but even it seems to have reached the limit now. Recently, I noticed that a few of the capacitors had gone missing (i.e. the capacitors in C11, C26, and C21) -- likely they came off while I was using it. What concerned me is.... how much will it affect the signal quality as a whole? Is it still possible for me to use it even with the few capacitors gone missing?
Unfortunately, I can't immediately replace the board with the new one for now, and I'm not sure how accessible the missing components are in my country for me to have the board fixed. So I'd like to hear your thoughts about the matter.
Thank you!
Comments
You can look up in the schematic what values those capacitors are. They can then be ordered and replaced by any competent electronics technician. A better solution in the future is to use some kind of case so your handling of the board does not adversely impact the components. Cases are available on the Shop page.
https://docs.openbci.com/Cyton/CytonSpecs/
C21 is a power supply filter cap on the ADS1299 ADC chip. Since there is a parallel C18 cap next to it, should not effect power supply noise significantly.
C11 and C26 are caps that are part of the RC lowpass pre-filter. C26 filters channels 6 and 7. C11 filters channels 4 and 5. One way you could test any ill effects is to connect your subject to both a known good channel, and a suspect channel in parallel. If both traces look identical, then you are ok. Actually these pre-filters only remove certain noise present in the electrical environment. In most cases this noise is not even present.
William