Firstly, let me say thankyou Dave for your open, unprompted and enthusiastic tear down of our inverter! It was wonderful to hear a fellow engineer explore his way through something you've spent *so many* hours working on. Your intuition of the various functions of each of the sections of circuitry was pretty much spot on too
I'm James (Webb), the balding chap in the blue shirt who features at 10:11 in the video. I'm the design engineer - Trevor is the business development guy and CEO, and together we are Platypus Instruments. You are correct Dave - the idea of the PI3 inverter was Trevor's, driven by the difficulty of obtaining power on remote worksites to conduct appliance tests in his day job as a test-and-tagger. I suggested we could make something, a prototype was created and the company was formed!
The unit you pulled apart was v3.3 - we're on to v3.4 now as we've been marching towards readying the design for production.. which has been (frustratingly) non-trivial! The main difficulties have been the multitudes of things that people have insisted on plugging into it during our (years) of field testing - and the unexpected results (read: learning opportunities). As some of the forum/youtube comments have suggested, the inclination is to plug the biggest, heaviest 15A load into it to see what it does. The first versions' output voltages sagged badly as a result of high output impedances. Fixing that caused the next versions to destroy themselves trying to drive a short circuit. Later versions brought better protection mechanisms, thermal management, transient capability, capacitive load stability, inductive load protection, battery management, creepage distances, lower THD etc etc.
And this is why no-one knows about us or our product yet - we've wanted to ensure it was bulletproof before offering them for sale. Product safety is an aspect we are paranoid about - as there's a lot of potential heat energy stored within that battery and a large amount of electrical energy stored within that capacitor for a device that we've seen many people drop and throw around. The microswitch that caught your attention just after opening the case is for exactly this reason - if the case is cracked/comes apart, the main capacitor is dumped into the pulse resistor standing up under the (cute) platypus logo. The same resistor takes the heat (literally) if the overvoltage crowbar triggers too.
Unfortunately, while a long time to market might be good for our consciences, it isn't good for business cashflow! We were most fortunate to receive an ACT government grant in 2014 to assist us with taking our prototype to production - and we mainly used the funds to pay for the creation of injection moulding tooling (to replace the 3D printed case your prototype has), patenting (which was a disappointing educational experience) and EMC/electrical safety testing - which is a process yet to conclude. I must admit, I'm most curious to know how a prototype that looks remarkably like the one I submitted for testing ended up in a dumpster a couple of years later...
I'm very happy you found it though - and stoked that we could present you with a puzzle to ponder. We'll have to send you a 'real' one when we finally make it to production!
In the meantime though, Trevor and my emails certainly work - even if our website doesn't. Please feel free to say hi or drop us a line at trevor@... and james@platypusinstruments.com.
Cheers!
[I'm dying to ask though: How on earth did you get a platypus to sit in a box for the title frame of the video??]
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