My first thought would be a tuned LC filter, resonant around 120 Hz. That would have avoided the noise problem and been far more reliable, and a whole lot cheaper.
When I was designing test equipment for factory floor operation we almost always put a Sola Brabd constant voltage transformer ahead of the controls and instrumantation power input. It was always cheaper than even one service call to fix a machine, and it gave us a reputaion for producing very reliable testing machines. The noise on the waveform on the scope traces looks a bit like it comes froman inverter drive circuit for a medium horsepower motor.
What are the engineering and design challenges in creating successful IoT devices? These devices are usually small, resource-constrained electronics designed to sense, collect, send, and/or interpret data. Some of the devices need to be smart enough to act upon data in real time, 24/7. Specifically the guests will discuss sensors, security, and lessons from IoT deployments.