Saturday, June 9, 2012

Amp Hour Meter moves to protoboard

Our Amp / Watt Hour Meter (we need a snazzy name for it!) has moved from solderless breadboard to a more permanent protoboard. We have drilled holes all the way through the protoboard for the ring terminals to the load and it's power supply (the big holes in the current sense board), and installed screws with nuts to attach ring terminals. There are larger nuts between the current sensor board and the protoboard as spacers. Washers are installed under the screw heads, above the current sensor board, and above the screw terminals. This protoboard not only holds the current sensor, but also contains the voltage divider for voltage sensing. There are only 4 connections to the Arduino:

Analog out (current)
Analog out (voltage)

and 3 connections to Load / Power supply

Power supply GND (-)
Power Supply + (P+)
Load + (L+)


  1. can this circuit be used to measure ac current? if not how can it be modified to measure ac current?

  2. yes, by using a different acs chip, like the ACS712. A slight change in the formula would be be necessary as well. It is a future upgrade for this project.