Expired Hot Deals

[Lowe's] First Alert Plug-in Electrochemical Carbon Monoxide Alarm for $14.79 starting on Jan 10

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  • Jan 11th, 2019 7:25 am
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Feb 8, 2014
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jaigandhi5 wrote:
Jan 10th, 2019 1:28 pm
This is the info I was looking for. The lifespan of 7 years starts AFTER installation, not when it's manufactured. Will purchase 1.

Thanks.
Some and this one may have a timer built in that beeps at exactly 7 years of being plugged in. When i was buying mine i was chatting with someone who said theirs beeped unceasingly starting at 7 years to the day from its installation
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Quentin5 wrote:
Jan 10th, 2019 6:49 pm
Some and this one may have a timer built in that beeps at exactly 7 years of being plugged in. When i was buying mine i was chatting with someone who said theirs beeped unceasingly starting at 7 years to the day from its installation
Yes, they count the 60Hz cycles on the AC line, when you hit 7 years they pretty much beep continuously.

A few years ago almost every house on my street had those things beeping within a few days of each other. My guess is the electrician was installing them house to house, resulting in each house being delayed less then a day from the previous. Kinda neat. Really annoying...
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repatch wrote:
Jan 10th, 2019 7:57 pm
Yes, they count the 60Hz cycles on the AC line, when you hit 7 years they pretty much beep continuously.

A few years ago almost every house on my street had those things beeping within a few days of each other. My guess is the electrician was installing them house to house, resulting in each house being delayed less then a day from the previous. Kinda neat. Really annoying...
That is hilarious!
But i can see the annoying

If its counting Hz thats 13,254,192,000 in 7 years.
Thats a lot of bottles of beer on the walls!
How do you know its counting HZ btw?
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Quentin5 wrote:
Jan 10th, 2019 7:59 pm
That is hilarious!
But i can see the annoying

If its counting Hz thats 13,254,192,000 in 7 years.
Thats a lot of bottles of beer on the walls!
How do you know its counting HZ btw?
Honestly it's a guess.

It's a pretty common technique for accurate timekeeping, most clock radios that were AC powered for many years relied on the 60 (or 50, depending where you are) stability for time keeping (there was recently an issue in the UK where the power regulator had slacked, generation hadn't maintained the 50Hz average and several clocks were showing slow)

The power grid maintains that over the long term the average frequency is almost exactly 60Hz. It does vary over the day, and over slightly longer periods, but they purposely continuously adjust things so that the average is exactly 60Hz.

As for the detectors, technically I don't know, I didn't take one apart. But frankly, there is ZERO chance, that over 7 years, the three detectors in my home would have 'expired' within such a small amount of time of each other using crystal oscillators. Crystal oscillators are accurate, and the home is relatively stable in temp, but over such a long period of time? I doubt it. You need to ovenize your crystal to get close.
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FYI, this model has an end of life alarm.
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Spinner wrote:
Jan 11th, 2019 12:02 am
FYI, this model has an end of life alarm.
I think that is mandated by at least one fire code, they all seem to these days.

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