There are people of diverse backgrounds selling on Tindie, but as far as I know, Jakub Polonský is the only one here with a PhD in electrochemistry. Though this gave him a good background in testing of electronic quantities for electrochemical systems, as far as designing electronics, he’s self taught. He graduated in 2012, but started with Arduino boards in 2010, allowing him to use this versatile tool for research purposes.
Polonský has been selling here since June of 2014, and offers test and measurement items that he’s made. I asked him to talk about the best parts of selling on Tindie.
Tindie is unique. A place that contains so much creativity and so many diverse things from people who actually designed them. It is so much different from the mass-produced generic stuff that you can buy on an auction site that begins with an “e” and ends with a “Bay”. The tight connection between the designer and customer is what I really like. I can talk with customers and if they want some feature or have a problem, I can directly solve it because I am the one who can add that feature and I know the most about my products. The conversations are very relaxed and friendly and often turn into a nice chat way past the initial issue.
As far as the worst, he notes that:
I am still not convinced that taking out pre-orders was a good idea… but I learned how to manage inventory so I am rarely out of stock.
Jakub believes the way you present information about products makes all the difference.
From what I have experienced, buyers like a good detailed documentation that can be understood even if they don’t possess such a deep knowledge of the item as the designer/seller does. So make the documentation thorough but readable. Test it on your friends/wife/grandpa 🙂
What could be considered the flagship product of his “Kaktus” store, the “MightyWatt” Arduino-controlled electronic load, was born out of his research.
I was involved in PEM fuel cell research and we had a commercial electronic load but its software was so-so and it was crashing frequently so I thought “hey, I can do this better and cheaper”. So I did and we ended up using six of MightyWatts, which costed less than one commercial load. The original application was thus PEM fuel cell testing but from my customers I know it’s being used in three main areas: solar cells, batteries and power supplies.
The device, which is now on its third revision, uses a FET as a variable resistor to maintain either a constant current load or a constant current drop. If you’re wondering, as I did, if a second resistor in series is needed to maintain the voltage drop, this is not the case:
It does not need any extra physical resistor. In the case of power supplies, they will switch to current-limited mode and in the case of batteries and fuel cells, their internal resistance will act as the second resistor so they have it “built-in.”
Pretty neat. So now you know that if you can produce something that “wastes” power in an extremely controlled and scientific manner, there’s actually a market for it. Polonský notes that, “I am really grateful that Tindie is there. I probably wouldn’t be selling MightyWatt at all if it weren’t for Tindie.”
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