[HN Gopher] Debugging my wife's alarm clock
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Debugging my wife's alarm clock
Author : zdw
Score : 86 points
Date : 2024-10-26 23:47 UTC (23 hours ago)
(HTM) web link (ntietz.com)
(TXT) w3m dump (ntietz.com)
| pryelluw wrote:
| Weirdly I ran into something similar many years ago. I took a
| similar alarm clock and hacked it to connect it the alarm signal
| to a stereo system with two 12 inch subwoofers. It was very very
| very loud. Neighbors could hear it a street over.
|
| Anyhow, I had to update how it powered the internal speaker
| (which I was taping into) because it was a little bit too much
| and the thing would reset.
|
| I'd go into more details but it was trashed and it's been about
| 20 years since ...
| sigseg1v wrote:
| I'd love an alarm clock that can replicate the sounds of my
| teenage youth via playing classics such as "Extreme Mario
| Dubstep - Yoshi Bass Drop (Womp Womp Edition Remix)"
| pryelluw wrote:
| That shouldn't be too hard these days. You can go the
| expensive route and use a raspberry pi but I know you can use
| something simpler. You can def do it for cheaper but an RPi
| does allow you internet connectivity and a buttload of other
| possible automations. Hell, add a zwave adapter and you can
| have the alarm flash your smart lights, and more!
| ajb wrote:
| I've got a label printer that uses a battery because it needs
| more current than (pre-pd) USB, but needing a battery when you
| also have AC seems a poor design. Especially a _non rechargeable_
| one.
| mongol wrote:
| The battery keeps the time so it does not reset the time at
| intermittent power outage
| ajb wrote:
| Yeah that's what happens in a _normal_ alarm clock. The OP
| thinks the design of this one is broken, hence my comment.
|
| But some other commenters seem to have a good theory that
| it's a failure in a component
| teruakohatu wrote:
| I am not sure I have ever owned more than one desktop alarm
| clock, but I have used a few, and in my experience by the time a
| real power failure occurs the 9v backup batteries have drained to
| the point that it resets anyway.
|
| I have also lived in a country where blackouts quite rare,
| usually just local blackouts due to a tree hitting a powerline,
| so in any given year I wouldn't expect one.
| poopsmithe wrote:
| I had one of these clocks in the past. I remember the clock
| working without a battery at all. The battery is only necessary
| if you want to unplug the clock and move it somewhere else
| without having to reprogram the time.
| Gare wrote:
| Or if the power goes out. Where I live, there are at least
| several outages per year.
| sgt wrote:
| Most places in the world that are slightly more exposed to
| weather than average run the risk of power outages. That'll
| be anywhere from Norway to Texas to Australia. In other parts
| of the world blackouts may be enriched by lack of grid
| capacity or incompetence.
| diggan wrote:
| > Most places in the world that are slightly more exposed
| to weather than average run the risk of power outages
|
| Heavily depends on how exposed the infrastructure is, I'd
| say. I currently live in Spain and been experiencing way
| more power outages than in Sweden, where I was born and
| raised, even though the weather is much more extreme in
| Sweden. Main difference, as far as I can tell, is that
| Sweden mostly digs trenches for all sorts of cables and
| infrastructure, while Spain tends to (still) hang cables in
| the air and on the outside of walls. I still get my fiber
| from a cable that comes hanging down from the front-side
| balcony of my flat here in Barcelona, and that's the
| official installation from my ISP.
| winrid wrote:
| Probably the transformer is bad or maybe a cap dried up, so it's
| just barely running on wall power.
| actionfromafar wrote:
| This
| sebazzz wrote:
| Caps dry out but transformers don't go bad unless dropped or
| something like that.
| greatartiste wrote:
| Sometimes if they get to hot or following many many
| heating/cooling cycles the insulation varnish on the
| transformer windings starts to fail leading to short circuit
| issues.
| winrid wrote:
| The varnish can wear down, but yes likely a cap
| avidiax wrote:
| > This isn't reproducible by removing the battery entirely,
| either. If you take it out, the clock loses all ability to
| function and just resets constantly. So having a mostly drained
| battery seems to be doing a little work so that it resets once
| but then resumes normal functioning (until the next time it tries
| to go off).
|
| I think what this really suggests is that the transformer and
| power supply are providing multiple voltages. The +9V rail is
| broken, but the other rail (maybe +5V) for the LED display is
| fine.
|
| So the alarm chip and the alarm sounder is running only from the
| 9V battery. If the battery is weak, then the sudden power demand
| from sounding the alarm is too much, the voltage dips and the
| chip resets.
| 05 wrote:
| > I think what this really suggests is that the transformer and
| power supply are providing multiple voltages. The +9V rail is
| broken, but the other rail (maybe +5V) for the LED display is
| fine.
|
| There's a reference design in the LM8560N IC PDF that suggests
| that the additional secondary winding is only used to drive the
| display, and all other electronics is powered off the main
| rail.
|
| The 10V cap is kaput and it can't filter the input power, 9V
| just acts as a filter (even a discharged one). The OP should
| replace the cap with a 16V one, because a 10V cap on a 9V rail
| just isn't right..
| walthamstow wrote:
| Can I get a straw poll on people who still use a dedicated alarm
| clock?
|
| I was born 1990+-2, but I have always been an old soul. I've been
| waking up to BBC Radio 4 since I was a teenager.
|
| My current one used to belong to my dad, it's a Sony dream
| machine with FM/AM, circa 2002.
| averageRoyalty wrote:
| I've been trying to find one that isn't full of ESP chips or
| phone chargers for a while, or at least one with a nice
| flashable chipset. They seem pretty rare these days.
| andai wrote:
| The first half of your comment implies a design from the 70s
| (which is my preference), but the second half contradicts
| that and is beyond my understanding. If you flashed an alarm
| clock, what would you make it do?
| tripper_27 wrote:
| Not too hard to build your own. Lots of tutorials based on
| i.e. ESP32 chips, various blinky light options. Google
| "Adafruit clock" to get started.
| adrian_b wrote:
| I have used dedicated alarm clocks until the death of my
| parents, and then I have retired the clocks. One of them was a
| Sony clock/radio that might have been similar to yours, which I
| had given to my mother because it had very big digits, so she
| could see the time clearly from a long distance.
|
| Another alarm clock had been built by my father, some 50 years
| ago, from medium-scale integration TTL circuits, before the
| apparition of dedicated integrated circuits for clocks. It
| still worked perfectly, and because it used a thermo-
| compensated quartz oscillator it had a much higher accuracy
| than the cheap quartz clocks or watches that can be bought now.
|
| Since then, whenever I need an alarm or to know the time, I
| just use a smartphone or computer. I was born much earlier, so
| I have used dedicated alarm clocks for several decades, but I
| do not like to use superfluous things, so I no longer use
| dedicated alarm clocks (or wrist watches or TV sets etc.).
|
| That does not mean that I do not like clocks, either mechanical
| or electronic. I like them, but I do no longer need them, so I
| like to examine them like I like to examine some ancient sword,
| which is beautiful, but for which I do not have any use in my
| daily life.
| hggigg wrote:
| I do. I have a Muji one.
|
| I don't allow anything more complicated than that, a light and
| a book in the bedroom.
| NeoTar wrote:
| Weirdly Nintendo released an alarm clock this month:
|
| https://www.nintendo.com/us/store/products/nintendo-sound-cl...
|
| Seems a strange thing to do in 2024.
| fallingsquirrel wrote:
| > Nintendo Switch Online required
|
| So it's an alarm clock that checks your subscription is still
| active before waking you up. Welcome to the future. I hope
| AWS doesn't go down around 6:45am.
| walthamstow wrote:
| I think the subscription is just required for the pre-sale
| before general sale. I really hope you're wrong about the
| sub being required for the damn thing to work, but it would
| not surprise me.
| endless1234 wrote:
| No. It's just a pre-sale for members. From below: "For a
| limited time*, paid Nintendo Switch Online members in the
| United States and Canada can purchase Alarmo online via the
| My Nintendo Store before it is available to purchase by the
| general public."
| phil21 wrote:
| I have since I had to switch to an iPhone for a new job about
| 9mo ago.
|
| Someone in their design team decided alarms are optional and
| that sometimes they should just go off silently for reasons.
|
| Utterly stupid feature I didn't have time to figure out so back
| to a real alarm clock for waking up on days it's important to
| do so.
|
| Whoever decided to make alarms "adaptive" at Apple must have
| never had a real actual honest job in their life. Utterly
| infuriating.
| ramses0 wrote:
| Yes, lots of times I have to double check: "Hey Siri, turn
| off the music in 1hr" => Timer => onFinish => "StopMusic()"
|
| ...but then if you re-use that timer (accidentally) it will
| be "sticky" to stop playing instead of chiming.
|
| Super frustrating! For as good as Apple's UX can be, they
| have some really bone-headed behaviors and designs in their
| core apps.
| tomjen3 wrote:
| You should have 3 copies of your data, on 2 different mediums,
| at least 1 one in a different location.
|
| I strongly believe that in the same way you should have at
| least 2 alarm clocks, one of which is of a different type. I
| strongly believe that you should use your phone and a dedicated
| alarm clock. Apple has released bugs that caused the alarm
| clock not to run, or do so at a wrong time. Likewise it is
| always possible for your normal alarm clock to lose power or
| run out of battery.
|
| Having both failures on the same day is a lot less likely.
| anarazel wrote:
| It's been only four days since a phone alarm would have let
| me sleep through giving a talk. Android rebooted, somehow got
| stuck in a reboot loop (I think), discharging faster than the
| crappy charger charged. Luckily jetlag worked in my favor for
| once...
| lostlogin wrote:
| > I strongly believe that in the same way you should have at
| least 2 alarm clocks, one of which is of a different type
|
| Very HN. And a redundant mode of transport to work, a backup
| fridge on a redundant power source.
|
| I draw the line after spare coffee grinding and brewing
| facilities.
| Hackbraten wrote:
| I do! I still use my Ramos clock [0], which unfortunately isn't
| being made any more.
|
| [0]: https://www.kickstarter.com/projects/2074185253/ramos-
| alarm-...
| masto wrote:
| Me too! I even repaired it when the speaker failed. The
| creator was very helpful in telling me the model of speaker
| and giving me some tips for opening the thing.
| crispyambulance wrote:
| Good riddance!
|
| I never had the patentice to fuss with actually setting the
| alarm using the irritating multiple-mode/single-button controls
| and extra layer of complexity of multiple alarms, alarms for
| weekends, and whether you want a pre-selected radio station to
| play rather than the buzzer. To make it worse, when I did wake
| up groggy to the alarm I invariably hit the largest button to
| make it stop-- snooze, only to be further irritated when it
| would go off again as I was having breakfast.
| nmcfarl wrote:
| I do.
|
| My eyesight is so bad that, without my glasses, I cannot see
| the numbers on my iPhone, even when using the big number
| display in standby mode. About a decade ago I got a cheap no
| name thing off of Amazon with a 4" high LED display. That I can
| see!
| quercusa wrote:
| I'm very nearsighted and the giant LED clock has been
| awesome.
| 10729287 wrote:
| Born in 1983. I do, because I don't want my smartphone in the
| bedroom and I have more trust in a more trivial device. I got a
| Wake up light by Philips I wouldn't switch for a phone, and a
| very small Casio pocket clock when I travel. This device is
| LOUD and I love it ;)
| Linux-Fan wrote:
| I use a dedicated alarm clock.
|
| Recently, I have built my own:
| <https://masysma.net/37/dcf77_vfd_raspi_clock.xhtml>
|
| Before that (and now for redundancy, I think my own one still
| has some minor bugs), I used a cheap one by "OK"
| <https://www.mediamarkt.de/de/product/_ok-
| ocr-310-2172968.htm...>.
|
| I don't like that I have to mash some tiny buttons to set the
| "OK" up and also to stop it. The LED that shows that the alarm
| is active is also hard to read for me. Hence I tried to improve
| upon this in my own design. I also found a solution to avoid
| the backup battery, but it is probably not what the "general
| public" would like to have either :)
| Cthulhu_ wrote:
| I've got a wake-up light, probably 10 years old by now. It's a
| dumb machine, no wifi or QI or anything, but it's got a leg up
| over "old-fashioned" alarm clocks; the clock is red lights and
| dimmable to "barely visible in daytime", it's a very adjustable
| light from just enough to not stumble to burning out retinas
| (and comfortable reading in-between), it's got a radio and
| builtin "gentle waking up sounds" that are actually pretty
| horrible because of the tinny speakers. But preferable over
| morning radio that's usually announcers laughing or terrible
| music.
|
| Downsides: Very expensive, it stopped working at one point but
| I replaced the power adapter and it was fine, tinny speakers
| like I said, and its design is round and on a very narrow base
| so it'll topple whenever you smack its touch sensitive surface
| to snooze it.
|
| Before that I had a traditional alarm clock with yellow
| letters, radio, the works, had that for like 20 years before
| replacing it. The letters on that were stupidly bright so we
| stuck an unused photo film in front of it with tape.
| jrochkind1 wrote:
| I still use one, in part because I don't want to require my
| phone in my bedroom.
|
| (Sometimes I have it in my bedroom sometimes not, just depends
| on where I happened to leave it when I go to bed. I do not look
| at the phone in bed).
|
| I have had this particular alarm clock for literally 35 years.
| What I prize about it is the ability to set the alarm time with
| two big dials on front, instead of having to press next-next-
| next buttons on the bottom.
|
| I do not know what I will do when it finally breaks.
|
| I can't find a picture of it online, I'm not sure if I'm
| describing it in a way anyone understands, it does not seem to
| be a well-known alarm clock. It is one (of many) "Sony Dream
| Machine" models, but most don't have this feature. The front
| has two big dials side by side. The left one has 24 marked
| positions, for each of the 24 hours in the day, color-coded for
| day and night. the other on the right has 12 positions for the
| 60 minutes in 5 minute increments. So you can just turn one and
| turn the other to easily set the alarm to whatever time you
| like (well, whatever time on 5 minute increments!)
| memcg wrote:
| My wife uses a Radio Shack alarm clock that looks nearly
| identical to the one in this post. It broke recently and I
| fixed it by removing about 3 inches of the power cord where it
| attaches to the transformer.
| andai wrote:
| Fascinating. I thought mains frequency was variable, which is why
| mains hum can be used to date recordings? It seems that there's
| some drift (why?) but they try to keep the _average_ constant,
| over some window?
|
| The article mentions the device prefers to use the mains
| frequency for timekeeping, using the crystal oscillator only as a
| fallback. I found this surprising, but I don't know much about
| either of those things.
| phil_k wrote:
| That's intriguing! I was under the impression that the mains
| frequency varied, which is why mains hum is useful for dating
| recordings. It appears there is some drift (but why?), although
| they aim to keep the average stable over a certain period. The
| article states that the device primarily relies on mains
| frequency for timekeeping, using the crystal oscillator as a
| backup. I found that unexpected, though I'm not well-versed in
| either topic.
| ipieter wrote:
| The mains frequency is literally how fast the generators in
| power plants are turning. If the load on the grid increases,
| those generators slow down slightly and more natural
| gas/coal/heat needs to be added to increase the frequency
| again. This whole process is quite complicated as not every
| plant can react in the same time. Some plants are always at
| 100% capacity, while others are dedicated to governing the
| frequency.
|
| So there are small fluctuations, often between 0.2 Hz around
| the base frequency, but the average is very close to the
| theoretical 50/60 Hz. And for an alarm clock that is good
| enough.
| mmastrac wrote:
| Older wall clocks used synchronous motors which would literally
| move the second hand using the waveform from the A/C power. As
| loads on generators went up, the effective RPMs went down,
| causing downstream power to run at slightly slower than 60Hz. It
| was so heavily used that power stations used to run "fast" catch
| up on any cycles they fell behind at night so that there were
| exactly 86,400 in a 24h period to prevent clocks from running
| fast or slow.
|
| Amusingly you'll see stories like this when power companies fail
| to maintain 60Hz on average over a day:
|
| https://www.reddit.com/r/explainlikeimfive/comments/xscztp/e...
| OptionOfT wrote:
| I remember this happening in Belgium, where they detected it
| quite like a month after the fact.
|
| Everybody got a letter in the mail (yes, snail mail!)
| explaining when they were going to run the system fast for a
| couple of hours to catch up.
| userbinator wrote:
| These were very common in the last century and many continue to
| be used today: https://en.wikipedia.org/wiki/Telechron
| userbinator wrote:
| _Update 10 /27: A few readers have pointed out to me that it's
| likely a bad capacitor, which cap it is, and how to test that
| and/or fix it!_
|
| When troubleshooting old electronics, rule #1 is "check the
| caps". Electrolytic capacitors are the most common failure item
| in solid-state devices. This alarm clock predates the infamous
| capacitor plague but the finite and somewhat short lifespan of
| electrolytics has been known since their invention.
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