At work some guys wanted me to set something up to easily measure 9 voltages at once. At first I was excited by the prospects of throwing together an easy celllog setup, splitting the 9 voltages over two different cellogs (5 on one, 4 on the other).
Today it came to light that the max voltages are actually as high as 5.7v, which was not what I was originally under the impression.
So I have been looking through the cell log hack threads and trying to understand why the cellog limit is 4.9v. Last time I went through the threads I saw an easier to read schematic of the op-amps, and I could sort of work through that, but I can't find it right now. The best thing I found was Doc's pictures on viewtopic.php?f=14&t=12815&start=15
, but I'm not familiar enough with electronics to understand the pictures of the tiny components.
I also remember there was a component that could not deal with 32v or something around that level, but technically I think my 5.7 split would put max 28.5v on any single Cell log (since I'm splitting the 9 voltages, 5 on one cellog, 4 on the other). Yet, not having that old schematic, I don't know if the split would help at all. TL;DR Version
: With that in mind, I'm asking if anyone knows why the cell logs have a 4.9v limit
, so I can get an idea whether or not 5s of 5.7v units (28.5v total) would kill the unit.
In the worst case, I can use voltage dividers, but right now I do not have the necessary very low tolerance resistors I would need on hand (precision is pretty important for this use), I'm not 100% sure how the load that the Cell log draws would affect a voltage divider, and, well, it would be kind of messy on each of 9 wires :-/. But! I will do this if I can't get around the 4.9v limit.
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