Andrew's Week 11 Progress Report

This week I continued to work with Ashley on developing accurate Active and Apparent Energy Readings.  We decided to use active and apparent accumulating registers from the ADE7763 which reset each time they are read.  We decided to use the micro controller as our timer and to get readings from the register every two seconds.  Ashley and I were able to get consistent values for power consumption using 0W, 200W, 400W, and 600W worth of resistive loads.  Ashley's report contains the values we got during these tests.  Before performing each test I used a voltmeter and digital clamp current meter to calculate power consumption for each source.We then used the known power consumption versus the active and apparent values to form linear equations using excel.  For  active and apparent energy we got an R squared value of .999 and 1 which reinforced our feelings about using the equation.

After feeling a sense of accomplishment I decided to begin concentrating on building the power supplies so that we can move our prototype into its final enclosure.  The power supplies for this project are relatively simple for two main reasons: line power can be utilized so energy efficiency is not a huge deal, only +5V DC is needed as a voltage for our entire circuit.  Despite the rather simple constraints the power supply will need to be built 3 times since our circuit has an isolated side, analog loads and digital loads.  Searching the internet I came across a site which provided good information about building simple 5V power supplies using the LM7805 linear voltage regulator, a device I am pretty familiar with.  The website referenced was: http://www.eleinmec.com/article.asp?16   Below is a schematic of the power supply design thus far.

I plan on each power supply having to supply minimal power (less than 500mW) however I still need to do the calculations to determine how much power each supply will need to produce.  If the power consumption is low enough I am hoping to get away with not having to mount the LM7805's to heat sinks.  I also plan on using a 9V AC input into the bridge so that less power has to dissipated by the regulators.

Over the next week I plan to finalize and build all the power supplies.  Once the supplies are built I also plan to begin building the project's final enclosure.  Ashley and I will also continue to test and fine tune our active and apparent energy readings.