Individual circuits in home and industry can now be accurately monitored by using a peel-and-stick electricity meter developed by Berkely Labs.
According to the published news by electronicsweekly.com, “It is an alternative to current transformers and live voltage connections that can be installed without main voltage working expertise as the sensors are simply stuck on the surface of each circuit breaker in a consumer unit. The only critical steps are aligning the sensor before sticking, and identifying the breaker type to the system so that calibration parameters can be loaded. Each sensor is 19 x 12mm including a capacitive voltage pick-up and a Hall-effect current probe. They are daisy-chained with ribbon cable which supplies power (5V 16mA) and takes serial data back to a local wireless node – based on a Raspberry Pi in the experiment. This links with a remote laptop running system monitoring algorithms, written in Python.”
Adding further the press release states, “Inside, the voltage probe is the bottom layer of the internal PCB and the Hall sensor is an Allegro A1301. Both signals are conditioned by op-amp-based filters and fed into the 10bit ADC of a MSP430G2131 microcontroller for serialisation and transmission along the ribbon cable. Voltage measurements are within 1 per cent of conventional contact probing, power below 10W can be resolved, and complex loads like triac dimmers can be handled. Time averaging is included to increase the signal-to-noise ratio of the Hall effect probe, and the laptop runs fairly complex power estimation algorithms that include software phase locked loops to track input waveforms.”