Timer Switch Knows When the Sun Sets: Pass or Fail?

This just seems unnecessary to me. My preferred strategy with lighting is to turn it on when I need it and turn it off when I don't; simple! Some people spent today foraging for food in landfills; I can't really begrudge my responsibilities when it comes to operating my light switches. If I decided that I did want to spend less time at the switches, I'd go for an auto switch with a light sensor in it. Why bother with all the coordinate stuff? It seems like a very complicated way to solve a simple problem. Or perhaps I'm missing something obvious....?

We use this to turn on our outside lights--especially when we're away.

The Aube device is much better than the other one you can find by Intermatic, which is actually a mechanical switch powered by a AA battery, and extremely unreliable. The Aube is a solid-state relay powered by line voltage, and the clock has a built-in backup battery.

"And why is longitude relevant?"

Right now days in the north of the US are shorter than days in the south of the US. My parents (NY) were just here (GA) and they commented on how much later the sun went down.

The closer you are to the poles, the more extreme the effect.

LA: That's Latitude.

Drew:

I logged in with the intention of writing what you so clearly articulated. I agree 100%.

The only use of timers that makes sense to me is for safety reasons. Turn on the lights when on vacation to give a false sense of someone at home. Does that require much accuracy? No.
I am sure this device can find it's place in the airline magazine and catalogs.

I could use this for my outside walkway and driveway lights, which are now on a timer anyways.

I've had two of these Aube switches to control my outdoor lighting for a couple of years now and they work superbly.

The simplistic comments dissing this device don't take into account those of us who are not on the premises when the light needs to be turned off or on. Like folks who leave the house in the dark to go to work and return after the sun has set. Or anyone away for the day. An indoor switch for an outdoor light makes a light sensor on the switch impractical. Many light sensors that work at the bulb will not work with CFL lighting - hence the value of this switch.

There's nothing complicated about either setting this simple device or using it. You set it once and let it do its job thereafter. Any gradeschool child could follow the directions.

This is a terrific energy saving device and should be a mandatory requirement for all outdoor lighting.

astral timeclocks are a great tool, just like any other tool. they have their purpose, and when used for that they're excellent. there are situations where you do want light when you're not "there" i.e. plant grow lights, security lights for public areas, step lights on stairs, and the like.

in this case, MIL can have a security feature (making her feel more secure, as well as making it seem like the house is occupied) that say turns on at sunset, and off at 10PM when she "goes to bed" it saves electricity (not on earlier when not needed) and will turn off at a certain time (which a photo cell won't do on it's own)

other implementations can be to turn off a photocel controlled fixture, or override photocel control of a fixture when it's not needed. i.e. a store front facade lighting turns off when the store is closed, but is photocel controlled so that it'll turn on earlier when dusk is darker sooner on an overcast day, but still turn it off during the "day" part of the day.

they're also ideal where you want to control a circuit that is remote, or does not necessarily have an appropriate location for a photo sensor.

a cheaper option for MIL would be to put her current timer on the maximum duration (30 min before sunset shortest day) and put a photo sensor inline with the lamp in her fixture. it'll still be off when it's bright, but will turn off every night at a set time (or a fuzzy time if you've got a shinier timer). n.b. not all of those retrofit sensors play well with CFLs

I've had one of these controlling my outdoor lights for 6 years and it works great.

Knowing the Lat and Long allows it to use the sunrise and sunset cycles correctly for on and off times.

Mine is auto in the morning (off) and evening (on) and uses a preset to turn on morning and off at nite.

Only thing I hate is the way to adjust for daylight savings time.

This has lasted longer than a GE product that was a timer in my master bathroom that failed after 1 year of lite usage.

Why is longitude important?

The sun doesn't rise at the same time for every point in the same time zone (even when they are at the same latitude). The eastern side of the time zone has sunrise/sunset sooner than the western side, simply because of the curvature of the planet and the eastward rotation.

I agree that there needs to be some sort of standard for controlling things from a central location. We're already able to send information over power lines in our homes, so adding some circuitry to devices we want to control would be fairly easy. But the only homes this seems to be in are ones set up by the manufacturers to showcase their technology.