Today I completed another small project. I’ve got this ‘smart meter’ in my house. The smart bit is that automatically sends off the meter data to the network provider. But I can not see the actual power usage from inside my apartment.
My meter has an infrared LED interface (right next to the meter above 1000 imp / kWh), which gives a pulse for every kWh consumed. By measuring the time between pulses and to count I’m on a current consumption in watts (3.6 / pulse duration to be exact).
The graph shows that it works well. I still can not explain all the peaks, but the high consumption (800W) between 10:30 and 16:00 is my electrical water boiler. The other major consumers are the refrigerator, the coffee and tea (for short peaks).
Measuring is knowing!
IR sensor diagram (led1 not used for now).
Closeup of the meter