Off-topic, but cool: http://www.transistorclock.com/?imm_mid=0da80b&cmp=em-prog-na-na-newsltr_201... A guy selling kits to make a all-parts-exposed digital wall clock that uses *no ICs* and *no crystals*. You build it yourself, 1250 parts to solder onto a custom board. Too pricey for me, otherwise I'd love to put one together. ICYW, I dug around the FAQ and he is cheating a bit: he's using the 60Hz of the AC as a timer source. Hmm, since it plus into AC, does that mean touching some parts of the exposed circuits might give you a nice zap?
Neat... And no @#$%! way am I going to spend that much time soldering together a clock, even if it was only $5. A not-overly-accurate-clock, at that! However, as noted in the details, there's a 120VAC-to-9VAC wall transformer involved, so even if you hung on to the bare leads with your hands, you wouldn't likely be getting anything more than an unpleasant tingle/buzz. Of course, I don't have all the details, and that looks (just eyeballing it) like a fairly hefty capacitor - the *possible* discharge current involved *could* be enough to be severely unpleasant. But not _likely_ to be harmful. Don't take this as any sort of guarantee, however. On the other hand, you could easily cover the bottom-left corner with a clear plastic shroud of some sort, and touching the rest of the board would likely (again...) be a non-event. -Adam On October 17, 2015 4:36:04 PM CDT, Trevor Cordes <trevor@tecnopolis.ca> wrote:
Off-topic, but cool:
http://www.transistorclock.com/?imm_mid=0da80b&cmp=em-prog-na-na-newsltr_201...
A guy selling kits to make a all-parts-exposed digital wall clock that uses *no ICs* and *no crystals*. You build it yourself, 1250 parts to solder onto a custom board. Too pricey for me, otherwise I'd love to put one together.
ICYW, I dug around the FAQ and he is cheating a bit: he's using the 60Hz of the AC as a timer source.
Hmm, since it plus into AC, does that mean touching some parts of the exposed circuits might give you a nice zap? _______________________________________________ Roundtable mailing list Roundtable@muug.mb.ca http://www.muug.mb.ca/mailman/listinfo/roundtable
-- Sent from my Android device with K-9 Mail. Please excuse my brevity.
On 2015-10-17 Adam Thompson wrote:
Neat... And no @#$%! way am I going to spend that much time soldering together a clock, even if it was only $5. A not-overly-accurate-clock, at that!
Think of it as a model plane or car we all (I'm sure) built as children. I would spend weeks on those. (Not sure what's more toxic, breathing in plastic cement glue fumes or solder fumes...)
However, as noted in the details, there's a 120VAC-to-9VAC wall
Ah, I didn't read that far. Good to see he's not leaving 120V exposed. I had guessed that since he was using AC as a timer that he wouldn't be able to use a wart as the conversion to DC would lose the effect: but I see he's cheating by going AC->AC, and then DC'ing the 9V on the PCB. Well, ok, I'm assuming the logic he's built up is based on DC! (Maybe I shouldn't assume anything else about his project...)
The AC frequency as a clock source will also be a problem of the utility happens to mess with that timing. Forget why the do, but it happens.
On Oct 17, 2015, at 14:36, Trevor Cordes <trevor@tecnopolis.ca> wrote:
Off-topic, but cool:
http://www.transistorclock.com/?imm_mid=0da80b&cmp=em-prog-na-na-newsltr_201...
A guy selling kits to make a all-parts-exposed digital wall clock that uses *no ICs* and *no crystals*. You build it yourself, 1250 parts to solder onto a custom board. Too pricey for me, otherwise I'd love to put one together.
ICYW, I dug around the FAQ and he is cheating a bit: he's using the 60Hz of the AC as a timer source.
Hmm, since it plus into AC, does that mean touching some parts of the exposed circuits might give you a nice zap? _______________________________________________ Roundtable mailing list Roundtable@muug.mb.ca http://www.muug.mb.ca/mailman/listinfo/roundtable
On October 17, 2015 6:09:21 PM CDT, Tim Lavoie <tim@fractaldragon.net> wrote:
The AC frequency as a clock source will also be a problem of the utility happens to mess with that timing. Forget why the do, but it happens.
On Oct 17, 2015, at 14:36, Trevor Cordes <trevor@tecnopolis.ca> wrote:
Off-topic, but cool:
http://www.transistorclock.com/?imm_mid=0da80b&cmp=em-prog-na-na-newsltr_201...
A guy selling kits to make a all-parts-exposed digital wall clock
that
uses *no ICs* and *no crystals*. You build it yourself, 1250 parts to solder onto a custom board. Too pricey for me, otherwise I'd love to put one together.
ICYW, I dug around the FAQ and he is cheating a bit: he's using the 60Hz of the AC as a timer source.
Hmm, since it plus into AC, does that mean touching some parts of the
exposed circuits might give you a nice zap? _______________________________________________ Roundtable mailing list Roundtable@muug.mb.ca http://www.muug.mb.ca/mailman/listinfo/roundtable
_______________________________________________ Roundtable mailing list Roundtable@muug.mb.ca http://www.muug.mb.ca/mailman/listinfo/roundtable
When the A/C grid is heavily loaded the generators slow below 60Hz. The make up for it in later by generating higher than 60Hz. That's why the old A/C clocks with synchronous motors never need correction over long periods of time. Most cheap digital clocks haven't had the oscillator regulated so their time creeps off. NTP fan, Daryl -- Daryl F
When the A/C grid is heavily loaded the generators slow below 60Hz. The[y] make up for it in later by generating higher than 60Hz. That's why the old A/C clocks with synchronous motors never need correction over long periods of time.
Yes, Daryl beat me to the answer. This was true back in the 1960's and into the 1970's, when Manitoba and Winnipeg Hydro went to these lengths to keep people's synchronous motor clocks running extremely accurately for a long time (sometimes well over a year with barely a one second deviation), and usually a power outage would be the limiting factor. However, I've noticed in the last 1-2 decades that this no longer seems to be the case, probably for lack of need. AC synchronous digital clocks I've observed (like on kitchen stoves) don't do that "catch-up/catch-down" any more.
Most cheap digital clocks haven't had the oscillator regulated so their time creeps off.
Yes, that is (or at least was) one of the benefits of a multi-$100 watch. A $300 Seiko watch I bought around 1981-1982 was guaranteed to deviate no more than 3 seconds per month, and my actual sample was within 2 seconds per month! Hartmut W Sager - Tel +1-204-339-8331, +1-204-515-1701, +1-204-515-1700, +1-810-471-4600, +1-909-361-6005 On 17 October 2015 at 23:02, Daryl F <wyatt@prairieturtle.ca> wrote:
On October 17, 2015 6:09:21 PM CDT, Tim Lavoie <tim@fractaldragon.net> wrote:
The AC frequency as a clock source will also be a problem of the utility happens to mess with that timing. Forget why the do, but it happens.
On Oct 17, 2015, at 14:36, Trevor Cordes <trevor@tecnopolis.ca> wrote:
Off-topic, but cool:
http://www.transistorclock.com/?imm_mid=0da80b&cmp=em-prog-na-na-newsltr_201...
A guy selling kits to make a all-parts-exposed digital wall clock that uses *no ICs* and *no crystals*. You build it yourself, 1250 parts to solder onto a custom board. Too pricey for me, otherwise I'd love to put one together.
ICYW, I dug around the FAQ and he is cheating a bit: he's using the 60Hz of the AC as a timer source.
Hmm, since it plus into AC, does that mean touching some parts of the exposed circuits might give you a nice zap? ------------------------------
Roundtable mailing list Roundtable@muug.mb.ca http://www.muug.mb.ca/mailman/listinfo/roundtable
------------------------------
Roundtable mailing list Roundtable@muug.mb.ca http://www.muug.mb.ca/mailman/listinfo/roundtable
When the A/C grid is heavily loaded the generators slow below 60Hz.
The make up for it in later by generating higher than 60Hz. That's why the old A/C clocks with synchronous motors never need correction over long periods of time.
Most cheap digital clocks haven't had the oscillator regulated so their time creeps off.
NTP fan, Daryl -- Daryl F
_______________________________________________ Roundtable mailing list Roundtable@muug.mb.ca http://www.muug.mb.ca/mailman/listinfo/roundtable
As long as you're going to pay too much for retro technology, why stop at transistors & 7-segment LED's?... Go for his Nixie tube clock! On 17/10/2015 4:36 PM, Trevor Cordes wrote:
Off-topic, but cool:
http://www.transistorclock.com/?imm_mid=0da80b&cmp=em-prog-na-na-newsltr_201...
A guy selling kits to make a all-parts-exposed digital wall clock that uses *no ICs* and *no crystals*. You build it yourself, 1250 parts to solder onto a custom board. Too pricey for me, otherwise I'd love to put one together.
ICYW, I dug around the FAQ and he is cheating a bit: he's using the 60Hz of the AC as a timer source.
Hmm, since it plus into AC, does that mean touching some parts of the exposed circuits might give you a nice zap?
-- Gilbert E. Detillieux E-mail: <gedetil@cs.umanitoba.ca> Dept. of Computer Science Web: http://www.cs.umanitoba.ca/~gedetil/ University of Manitoba Phone: (204)474-8161 Winnipeg MB CANADA R3T 2N2 Fax: (204)474-7609
why stop there use a sun dial On 15-10-19 09:45 AM, Gilbert E. Detillieux wrote:
As long as you're going to pay too much for retro technology, why stop at transistors & 7-segment LED's?... Go for his Nixie tube clock!
On 17/10/2015 4:36 PM, Trevor Cordes wrote:
Off-topic, but cool:
http://www.transistorclock.com/?imm_mid=0da80b&cmp=em-prog-na-na-newsltr_201...
A guy selling kits to make a all-parts-exposed digital wall clock that uses *no ICs* and *no crystals*. You build it yourself, 1250 parts to solder onto a custom board. Too pricey for me, otherwise I'd love to put one together.
ICYW, I dug around the FAQ and he is cheating a bit: he's using the 60Hz of the AC as a timer source.
Hmm, since it plus into AC, does that mean touching some parts of the exposed circuits might give you a nice zap?
participants (7)
-
Adam Thompson -
Daryl F -
Flaggmann -
Gilbert E. Detillieux -
Hartmut W Sager -
Tim Lavoie -
Trevor Cordes