We received the Arduino shield and emonTX today and they look to be very well designed.
I’m dreadful with an iron and normally an associate of mine does all our soldering but I’m pleased to say my novice skills were enough and it’s happily kicking out data.
We are currently reviewing various energy monitoring systems, not just the one’s supplied by Open Energy Monitor. The basic criteria is value for money, ease of assembly, accuracy and safety considerations.
Yesterday before the additional OEM parts arrived I completed your breadboard circuit with a Leonardo.
Observations with the 100A CT and 9V AC - AC adaptor.
Voltage accurate until we power up the load (1200W hairdryer). We noticed a 2V drop from 238 to 236. This results in real power being greater than apparent power. 2V is less than 1% and we could probably factor this into our system.
Also about 130mA of noise to accommodate.
With the Arduino shield, hooked up to the same Leonardo the noise seems to have all but disappeared. However we are still seeing the 2V drop and PF > 1.
Once we have the results from the emonTx we will post them here.