Chris Gammell and Dave Jones' voices span the chasm of thousands of miles each and every week to speak to each other and industry experts about where the field of electronics is moving. Whether it be a late breaking story about a large semiconductor manufacturer, a new piece of must-have test equipment or just talking through recent issues with their circuit designs, Chris and Dave try to make electronics more accessible for the listeners. Most importantly, they try and make the field of electronics more fun. Guests range from advanced hobbyists working on exciting new projects up through C-level executives at a variety of relevant and innovative companies. Tune in to learn more about electronics and then join the conversation! Visit The Amp Hour website for our back catalog of 150+ episodes.
https://theamphour.com
#371 – 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