[HN Gopher] Linear Clock: Solar
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Linear Clock: Solar
Author : firloop
Score : 48 points
Date : 2021-05-04 18:17 UTC (4 hours ago)
(HTM) web link (jmw.name)
(TXT) w3m dump (jmw.name)
| _Microft wrote:
| Cool project and kudos to them for working through the necessary
| math to calculate sunrise and sunset.
|
| You can see a few more pictures on the "Shop" page [0]. They are
| hidden behind the "View product"-button. I've extracted a few
| links and modified them to link to larger images [1-3]. The power
| supply is connected via a barrel connector as can be seen in
| image [3]. I guess I would have used a USB power supply instead,
| just because of their ubiquity.
|
| [0] https://jmw.name/shop/
|
| [1]
| https://cdn.shopify.com/s/files/1/0557/1513/5639/products/li...
|
| [2]
| https://cdn.shopify.com/s/files/1/0557/1513/5639/products/li...
|
| [3]
| https://cdn.shopify.com/s/files/1/0557/1513/5639/products/li...
| jmwilson wrote:
| I actually used a USB connector on the previous Nixie-tube
| based version. It's harder since there aren't as many panel-
| mount options for the USB connector. You have to design the
| circuit board around abutting the enclosure wall. This makes
| sense in an injection molded or unibody construction, but less
| so with a wood box like this.
|
| You're also potentially limited by the USB spec on current
| draw. There are ways around this, like ICs that will detect if
| you're connected to a charger or a data port. The barrel
| connector is also quite ubiquitous and I designed the power
| entry to work across a wide range of DC power adapter voltages.
| _Microft wrote:
| Thanks for the explanation, that makes sense.
|
| I have also discovered the previous version now ([0], if
| someone else is curious as well) and will have a look at it
| later.
|
| [0] https://github.com/jmwilson/leave-time-behind
| imoverclocked wrote:
| Or a small solar cell?
| teraflop wrote:
| I love this project, and this is meant as an honest question
| rather than criticism: has the creator given any thought to FCC
| certification?
|
| My understanding is that in the US, this device would be
| classified as an "unintentional radiator". If you want to sell it
| as a finished product to consumers, then you're legally required
| to get it tested by an ANSI C63.4 compliant lab to ensure that it
| meets the legal limits for RF emissions into the air and the
| power grid. AFAIK the typical cost for a round of testing is
| >US$1000, and it needs to be repeated if you make hardware
| changes of pretty much any kind.
|
| I've occasionally considered making and selling projects kind of
| like this one as a hobbyist, but it seems like the cost of
| compliance testing means that you have to be reasonably sure that
| you'll sell at least a few units, or else you're just throwing
| money away.
| jmwilson wrote:
| It's a good question and something I'm looking into as I
| consider the idea of selling them. It's something that has to
| be approached in the context of other changes (like BOM
| optimization) for larger manufacturing.
|
| I've studied SMPS design and am not totally oblivious to
| conducted and radiated EMI issues. I took several
| considerations in the project like analyzing current loops and
| taking near-field measurements on a spectrum analyzer. However,
| what ultimately matters is what happens in the testing chamber.
| SamBam wrote:
| Beautiful.
|
| What is the blue dot for?
| speps wrote:
| > The sunset indicator was immediately interesting. Days are
| longer in the summer and shorter in the winter, but I never
| quantified it for myself. How might I plan my day differently
| with a clear indicator of the balance available between daytime
| and nighttime hours?
| unfamiliar wrote:
| Looks great. The use of a CNC seems a bit overkill, when it looks
| like a trim router + template would have done the same job with
| zero CAD modelling required. Unless I'm missing something.
| eterps wrote:
| Wow, great project!
| PaulDavisThe1st wrote:
| This is cool, but I think I'd have done the design just a little
| differently. The author noted that seeing when the sunset was had
| some effect on his perception of day length. I think I'd design a
| similar clock to have sunrise and sunset markers, and the
| continuous bar would show the position within 24hrs. That would
| make me even more aware of which parts of the day I was using,
| and their relative durations.
| speps wrote:
| Reminds me of this article:
| https://www.hodinkee.com/articles/the-eerie-beauty-of-the-ap...
| [deleted]
| jmwilson wrote:
| I thought about that, but I wanted to ground the display in the
| natural cycle of the day. Once you introduce wall-clock time
| into the design, there are at least two problems that need
| solving:
|
| 1) what's the timezone? 2) what about DST?
|
| The first is quite complex and requires knowing more than just
| lat/lon. Dates of DST also do change over time according to
| policy. The only solution I saw for these would to go full IoT
| so it could talk to NTP servers or have a control interface,
| and that would ruin the plug-it-in-and-it-just-works minimalism
| I was going for.
| PaulDavisThe1st wrote:
| Entirely fair set of decisions! Thanks for the reply.
| xd1936 wrote:
| I was thinking this as well. Having the start and end of the
| bar be midnight, with two dots representing sunrise and sunset,
| is way more intuitive to me.
| xd1936 wrote:
| Gorgeous! I have a soft spot for an unusual clock design or
| orrery. I've been trying to learn Adafruit's NeoPixels for a
| quasi-similar project and the world of soldering and wiring is
| way different than firing up a new Git repository!
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