Comments on: Looking for a smart power strip.

Question: Looking for a smart power strip.

floam — Mon, 14 Jan 2008 22:26:08 -0800

Looking for a smart surge protector that shuts down peripherals when a computer is turned off or asleep.

I've seen a few devices (some UPSs, surge protectors) that can do this when the master device is turned off. But a few weeks ago I found one that will kill the power to the remaining devices even when the master is sleeping -- it detects when it starts just using a trickle of power. Only problem is now I can't find it. Anyone have any ideas? I have like four wall-warts that are always warm, it'd be cool to be able to have them not getting any juice for 3/4 of the day.

By: pupdog

pupdog — Mon, 14 Jan 2008 23:25:19 -0800

I haven't seen the one you're describing, but this unit was just featured a couple days ago, and would seem to give you some of this funstionality - shutting off several of the outlets when you don't need them, but still having a couple of 'always-on' ones...

By: rhizome

rhizome — Mon, 14 Jan 2008 23:40:28 -0800

I don't think it's exactly what you're thinking of, but you could certainly rig this up with X-10 home automation stuff and some scripts/utils. Then again, someone might come along and say that warm wall warts don't consume electricity.

By: krisjohn

krisjohn — Tue, 15 Jan 2008 00:08:45 -0800

Is this what you're after?

By: floam

floam — Tue, 15 Jan 2008 00:16:43 -0800

krisjohn: I don't think so. I've seen a few of those but they only power off the wall-warts when the main device is 100% powered off. A new one I saw was smart enough to discover that it's only asleep, and turns the rest of the devices off then.

By: meowzilla

meowzilla — Tue, 15 Jan 2008 00:47:56 -0800

I wouldn't rule out the Smart Strip so quickly. I've got one connected to my computer, and when I put the computer into suspend mode, all my peripherals turn off. When I wake up my computer, all of them turn back on (of course, my keyboard and my monitor don't work - but this is probably due to the KVM switch in between malfunctioning).

These smart power strips aren't actually that smart - you have to tune them to set the threshold power draw below which the other devices will get turned off. Keep in mind that the computer also has a trickle power when turned off, and a higher number for sleeping. So to get it to work with a sleeping computer, you just need to turn the threshold up higher.

For example, if the control device draws 1 power unit while off, 5 power units while sleeping, and 50 power units while completely on (these figures are completely made up):

A threshold of 0-1 power unit means that all the accessory devices will constantly be on.
A threshold of 1-5 power units means that when only the control device is off, all accessory devices will be off. When the control device is sleeping, accessory devices will still be on.
A threshold of 5-50 means that when the control device is off or sleeping, all accessory devices will be off.
A threshold of >50 means that all accessory devices will always be off.

So it's just a matter of putting the control device to sleep and changing the threshold so that the accessory devices turn off. It's kind of a pain to set up, but it very rarely changes.

I know there's a fencepost error in there somewhere, but I didn't want to make it even more complicated

By: phearlez

phearlez — Tue, 15 Jan 2008 12:18:08 -0800

I think krisjohn is right. From the description in that link:

Learn how it works.
A small electronic device inside the Smart Strip monitors the current on a single outlet. The computer is plugged into that single outlet. When the computer is finished shutting down, the current draw from the computer drops to its idle current -- and the Smart Strip senses the current change, automatically shutting off all of the computer peripherals.

If you look in the FAQ it also indicates there's an adjustment knob to twiddle the sensitivity.

The Energystar guidelines specify what the wattage should be when in sleep mode, if you're curious about those thresholds.

By: floam

floam — Tue, 15 Jan 2008 23:20:29 -0800

Aha! Thanks!