tangent
Top Mall-Fi poster. The T in META42.
Formerly with Tangentsoft Parts Store
- Joined
- Sep 27, 2001
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Both bran damages fixed.
Originally Posted by tangent /img/forum/go_quote.gif I've updated the PIMETA v2 docs to distill some of what we've covered here. Better coverage of how NiMH batteries behave, with pretty graph Redrawn schematic, human-friendly |
Originally Posted by headfone /img/forum/go_quote.gif I'm experimenting with running two 9.6V 230mAh (ea.) cells in parallel. |
Originally Posted by headfone /img/forum/go_quote.gif Currently, I'm experimenting with running two 9.6V 230mAh (ea.) cells in parallel. |
I've updated the PIMETA v2 docs to distill some of what we've covered here.
Redrawn schematic, human-friendly
I recall that being a 1M ohm resistor, not a 499 kilohm & 4.7pF. O.K v2 vs V1
10pF or 4.7pF that is the question.
220pF is way to big for an 8 Megohm buffer input impedance
Yes, I lowered those resistors because there's no reason for them to be 1M if the largest likely pot value is 50K. If it makes you happy to use 1M instead, you can. It will just raise the noise floor a bit.
Answered here in the docs.
Where are you getting 220pF?
I wish I had seen that back in 2006 when I first drew up the op-amp and buffer schematic
Quote:Where are you getting 220pF?
BUF634 datasheet, Page 9, FIGURE 4. "Boosting Op Amp Current.", [on chart in Figure 4] with OPA627, OPA132.
With PIMETA v1 battery life, the BUF634 [bandwidth pin] resistor value may be of importance?
Would battery life testing with "Pink noise" or "White noise" into a predetermined ohm dummy load, rather then just a single sine wave be more accurate or useful at all?
can it be done easliy without a full fledged lab?