I unfortunately cannot read your ascii art, which in itself is disappointing.
2k is a bit low for a divider - you'll get standby current of 6mA. You should also try optimizing the split to fit the range you can measure. So you'd want a ratio of R2/Rtotal =measured range/ measurable range. So 2.2k/10k would give you standby of <1mA and a range of 12.2V. As for diagnosing your actual problem, I'd get out a meter or scope to determine which end your issue is on. Colin > On Feb 21, 2015, at 11:29 AM, Peter Hollenbeck <[email protected]> wrote: > > I am using a LinkUSB and an MS-TV to read voltage from a 12 volt system. The > MS-TV is limited to 10 volts so a made a voltage divider. I know next to > nothing about electronics. Two weeks ago, with a test 12v power supply I > played with various resistor values, from 1K to 1M. The 1K resistors appeared > to give the best reading, about 6 volts. The higher the value the lower the > output. Now, working with a real 12v battery system I am getting values > ranging all over - .1, .82, .07, 10+, and rarely something reasonable, like > 6.6.Within several minutes I just got 0.7 followed by 9.75. An inverter > connected to the battery bank displays 12.1 volts and the output from my > program shows .71 volts. > > My divider looks like this: > > 1K 1K > ---------^v^v------------^v^v----------------------- > | | | | > | | | | > | | | | > | | | | > battery (+) | | battery (-) > MS-TV MS-TV > red wire black wire > > I sure would appreciate suggestions. > Thank you, > Peter > > ------------------------------------------------------------------------------ > Download BIRT iHub F-Type - The Free Enterprise-Grade BIRT Server > from Actuate! Instantly Supercharge Your Business Reports and Dashboards > with Interactivity, Sharing, Native Excel Exports, App Integration & more > Get technology previously reserved for billion-dollar corporations, FREE > http://pubads.g.doubleclick.net/gampad/clk?id=190641631&iu=/4140/ostg.clktrk > _______________________________________________ > Owfs-developers mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/owfs-developers ------------------------------------------------------------------------------ Download BIRT iHub F-Type - The Free Enterprise-Grade BIRT Server from Actuate! Instantly Supercharge Your Business Reports and Dashboards with Interactivity, Sharing, Native Excel Exports, App Integration & more Get technology previously reserved for billion-dollar corporations, FREE http://pubads.g.doubleclick.net/gampad/clk?id=190641631&iu=/4140/ostg.clktrk _______________________________________________ Owfs-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/owfs-developers
