I'd like to use my BeagleBone Black to build a small power efficiency station for my school. For that I plan to measure power consumption using a current transformer and a voltage transformer, feed the data into a small & fast database and show it through a web interface to the school staff. I see that 50 Hz are not a problem for BB ADCs, but I'm not sure at all using them is a good idea. Intially I planned to use the same voltage I must measure to power the BB. I'm starting from a circuit like the attached one (replacing the UA78M33 by a UA7805CKCT which provides up to 1.5 A output)
<https://lh4.googleusercontent.com/-Rh9IrbXEzAU/UnFV0UcdTSI/AAAAAAAAEAM/TduMV2A5CT4/s1600/adc.jpg> Changing the R1/R2 divisor I can make the 220V signal lower , but I'd always get a signal with a negative side (-0.9V - +0.9V) in the best case. Same for the current transformer, after applying its output to a 100 ohms resistor. So, first, is it an awful idea to use BB for this purpose? If not, how can I avoid the negative part of the signal before feeding the BB ADCs? Thanks in advance -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
