Post by papaof2 on Jun 20, 2023 19:05:08 GMT -6
It was totally unintentional, but I'm now involved with some tiny alternate power. The better half used an Amazon gift card I gave her to buy a new dress watch - a Seiko Solar.
Nothing obvious about it being solar-charged as the face is white, with a tiny bit of texture. Info on charging in the watch's user manual is defined in LUX or "fluorescent office lighting" (700LUX) or "fluorescent 30 watts at 20cm" (3000LUX) or "cloudy day" (10,000LUX) or "sunny summer day" (100,000LUX).
Searching through my collection of esoteric tools, I did find a light meter - one that reads in foot candles (FC) and LUX. All but one of the under-cabinet fluorescent lights in the kitchen has been replaced by LED strips but that one light is in a seldom-used corner so that might be a good place to charge the watch. So what does the LUX meter say? 1315LUX
Take Seiko's list and build a formula that plugs 1315LUX in place of the 3000LUX and see what the resulting numbers are. After a couple of passes (I'm on some serious pain meds at the moment, so any math gets checked again some hours later), I have some reasonable numbers - all the times are more than twice as long as the 3000LUX chart in the user's manual: 1315 is less than half of 3000 so those are reasonable numbers.
And the final numbers are?
Using the 15(?) watt fluorescent bulb, going from dead battery to full charge would take 17 days. Getting enough power for one day would take 1.33 hours. However, these numbers are only for days you can't be outside. Full charge time in summer sun is 10 hours, 60 hours on cloudy days or 180 hours of 3000LUX (30 watt fluorescent at 20cm). Charge for one day is 2 minutes in summer sun, 12 minutes on a cloudy day, 35 minutes of 3000LUX (30 watt fluorescent at 20cm) or 3 hours of typical fluorescent office lighting. So the fluorescent lamp under the cabinet is faster than typical office lighting and probably a place to leave the watch overnight once every 10 days or two weeks - unless she wears the watch while walking out to get the mail and it gets tomorrow's charge of sun on that trip ;-)
Would this watch survive an EMP or a CME? No idea. If it did, you might have useful time-keeping for a long time if you kept the battery close to fully charged. If the watch stopped under those circumstances, you might have difficulty finding out the correct time so you could reset the watch - maybe have next year's almanac with sunrise/sunset times? Of course, those times would work for setting any other timepiece. Perhaps a sundial is in everyone's future? There are lots of DIY sundial projects available online and in many "Things For Boys" books - although we had daughters and grands who would have wanted to build sundials if I'd thought about it at the right time - Lincoln Logs and birdhouse kits were well received so a sundial probably would have been.
Nothing obvious about it being solar-charged as the face is white, with a tiny bit of texture. Info on charging in the watch's user manual is defined in LUX or "fluorescent office lighting" (700LUX) or "fluorescent 30 watts at 20cm" (3000LUX) or "cloudy day" (10,000LUX) or "sunny summer day" (100,000LUX).
Searching through my collection of esoteric tools, I did find a light meter - one that reads in foot candles (FC) and LUX. All but one of the under-cabinet fluorescent lights in the kitchen has been replaced by LED strips but that one light is in a seldom-used corner so that might be a good place to charge the watch. So what does the LUX meter say? 1315LUX
Take Seiko's list and build a formula that plugs 1315LUX in place of the 3000LUX and see what the resulting numbers are. After a couple of passes (I'm on some serious pain meds at the moment, so any math gets checked again some hours later), I have some reasonable numbers - all the times are more than twice as long as the 3000LUX chart in the user's manual: 1315 is less than half of 3000 so those are reasonable numbers.
And the final numbers are?
Using the 15(?) watt fluorescent bulb, going from dead battery to full charge would take 17 days. Getting enough power for one day would take 1.33 hours. However, these numbers are only for days you can't be outside. Full charge time in summer sun is 10 hours, 60 hours on cloudy days or 180 hours of 3000LUX (30 watt fluorescent at 20cm). Charge for one day is 2 minutes in summer sun, 12 minutes on a cloudy day, 35 minutes of 3000LUX (30 watt fluorescent at 20cm) or 3 hours of typical fluorescent office lighting. So the fluorescent lamp under the cabinet is faster than typical office lighting and probably a place to leave the watch overnight once every 10 days or two weeks - unless she wears the watch while walking out to get the mail and it gets tomorrow's charge of sun on that trip ;-)
Would this watch survive an EMP or a CME? No idea. If it did, you might have useful time-keeping for a long time if you kept the battery close to fully charged. If the watch stopped under those circumstances, you might have difficulty finding out the correct time so you could reset the watch - maybe have next year's almanac with sunrise/sunset times? Of course, those times would work for setting any other timepiece. Perhaps a sundial is in everyone's future? There are lots of DIY sundial projects available online and in many "Things For Boys" books - although we had daughters and grands who would have wanted to build sundials if I'd thought about it at the right time - Lincoln Logs and birdhouse kits were well received so a sundial probably would have been.