1. 28

  2. 12

    Finally, this book never runs out of batteries, and is compatible with the most popular API in the market - printed name card, receipts, and drawings. It loads instantly no matter where you are - the Great Firewall of China can’t filter it. You actually own your copy of this book - unlike software, it’s not licensed to you via a click-through EULA that robs you of all your fair use rights. It also can’t be infected with malware, has no pop-up ads, and will never upload confidential notes about pricing, sources, and vendors to the cloud. Your data is your data!

    Love this paragraph.

      1. 2

        Yes, that’s the blog post that announced that this was being released, I figured I’d link to the “meat” of it. :)

      2. 2

        Sometimes components are of a lower spec, but labeled as higher. This is particularly common in FLASH memory, batteries, or any product that features multiple grades in identical casing (e.g. phones with different internal storage capacities). I also suspect this happens in capacitor and resistor tolerances and tempcos, but I haven’t done a rigorous study to confirm the suspicion.

        What is “tempco”?

        I found this jargon-infused article, but I still don’t know what tempco is. Clearly it’s a numeric range..

        1. 3

          According to Google, it’s “temperature coefficient”, which is a measure of how a voltage measurement circuit’s output varies with temperature. For a digital system like flash memory, I suspect this maps to how sensitive its error rate is to different temperatures.

          1. 4

            That’s pretty much it.

            Digital-only parts usually only have a temperature rating, because a “coefficient” by which a digital part gradually goes out of spec is not usually realistic or desirable. For example, a part is specified to operate in the industrial range of -20 to +85C - probably it fails “more” at 200C than 150C, but that’s not a distinction most flash memory customers or users care about.

            Capacitor & resistor tolerances and ratings are subtly different because these things are more “analog” and do incrementally go out of spec. For example ceramic capacitors have a 3 letter code which indicates their “class”, including temperature coefficient properties. This lets the designer know the temperature range across which they deviate at most x% from their nominal capacitance: https://www.raviyp.com/embedded/217-difference-between-x7r-x5r-x8r-z5u-y5v-x7s-c0g-capacitor-dielectrics

            1. 1

              Sounds legit! Thank you.