In the development pipeline

I’ve been working on a set of hardware upgrades over the past few months, and things are starting to come together. Today I received the new PCB and stencil for a rev 4.9 IoTaWatt. I populated it and fired it up and it’s working as designed.

Looks a lot like the rev 4.8, no surprise there, but the big difference is two additional AC reference plugs on the back. These plugs can be used to bring voltage reference into inputs 13 and/or 14. The switches built into the connectors automatically change the input from CT to VT when you plug in a VT. So this eliminates the need to remove the burdens and use an external adapter to do direct reference three-phase. You could also use one of them to monitor the L2 of a split-phase US panel if so inclined.

I have used this dual circuit in a previous design, but the openings in the enclosure were prohibitive. So another project that is ongoing to reduce cost is to have a mold fabricated to produce the enclosure. That process is well along and I’ve got a prototype of the new design printed on a 3D printer:

Notice that the rear face now has openings for the two AC plugs. The mold will have removable dies so that it can produce enclosures with and without these openings. Also note the integrated wall mount tabs

So I configured two extra VTs on inputs 13 and 14 and all looks good:


The mold will be made in China, but then shipped back here to New Hampshire where the production enclosures will be made, contributing to a significant cost reduction and simplification of assembly. Have to repeat some of the safety tests, and it should all come together sometime in March.



It is great to see the continuous innovation of the IoTaWatt platform. I am also proud to support a product that is not only Made in America, but also in my old home state of New Hampshire. I grew up in Nashua, but moved to North Carolina after college to pursue my career in Electrical Engineering.

Keep up the great work! And keep the blog updates coming! I really enjoy them.

Live Free or Die,


1 Like

A couple of superb enhancements.