Circuit 10.4 (electrodes)
Changes compared to Circuit 10.2 (electrodes):
- Fixed aggressive filtering of signals by changing passive highpass filter capacitors C1-C8 from 100pF to 100nF. (This was covered in a blog post)
- Changed the gain for all amplifiers to 251x. (Some amplifiers had a gain of 501x due to a sensitivity bug, this is not necessary anymore.)
- The circuit preview image was generated by KiCad 6 instead of 5, and may contain additional cosmetic changes with no functional impact.
Changes compared to Circuit 10.1 (electrodes):
- Gain resistors R9, R11, R12 have been reduced from 1000 Ohms to 100 Ohms, raising the gain tenfold, from 51x to 501x.
- Gain resistor R10 was only reduced to 200 Ohms, raising the gain to only 251x. This was done to offset an interference bug along the out2 trace of Electrode Module 3, Electrode Module 3.1 and Electrode Module 3.2. Once this is fixed, the resistance should be set to equal that of R9/R11/R12 once again.
- JP1-JP8 are now closed by default, to save time during assembly