An Interview With Joe Bamberg

Welcome Joe Bamberg, Lead Hardware Engineer at Sense

• Joe went to school at Miami, studying for pre-med.
• After a masters degree in EE, he ended up at Analog Devices (ADI) working on Energy metering ICs.
• Lyric labs
• Most meters are electromechanical, using moving parts to measure current via the Right Hand Rule. This then turns a wheel which measures "impulses per kwh"
• Past guest Larry Sears worked connected (gas!) meters.
• The first meters that weren't manually read used IR.
• Different generations of smart meters moved from measuring active power (Watt hour meter) to reactive power (VAR / apparent power / power factor / Line sag)
• Most homes have a power factor of 1 because of the primarily resistive loads.
• The onboard "filter based metering" used Hilbert filtering (transforms)
• Measuring current
  • CT - current transformer
  • Shunt
  • Rogowski coil
• Joe worked on parts like:
  • ADE7755
  • ADE7858
• After ADI he ended up at Qualcomm / Pixtronics working on MEMS display technology. It used an IGZO (indium gallium zinc oxide) process
• The Sense is primarily in the US and Canada right now, measuring split phase, 120V power.
• Founder Mike Phillips has lots of experience with speech recognition (and disaggregation), which translated to the signal processing on Sense.
• Chris asked about if Sense shuts down, Joe later updated that this was addressed on the Sense blog.
• Internally there is a front end, isolated flyback, iMX7 and WiFi. It runs a custom distro of Linux.
• It's not just for monitoring power, it also monitors events. For instance, one of Joe's co-workers got a message "Your sump pump is kicking on"
• The solar version ships another set of CTs
• Edge processing (computing)
• There are a bunch of regulations NEC, UL, FCC, CE, CISPR
• Bolt helped with the initial mechanical design.
• It's small because of the variable size of installation cavities.
• Have more questions? Find Joe on Twitter as @thejoebamberg