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Automatic Standby Switch Answered

I stumbled upon this little gadget...and thought I'd share it with you all. It seems like something that a lot of you could make pretty easily. The concept is simple, it plugs into the wall, and your device plugs into it. As soon as it detects your appliance/device is in standby mode, it cuts the power. Just a simple way to save the power that your junk sucks in when you're not using it. As NachoMahma pointed out to me, one big improvement would be automatic reset.

Anyways, if someone wants to give it a shot, i'd love to see the instructable on it.


I've thought of something like this before, but once it's off, how can you make it turn back on? how can it detect that whatever device is now drawing more current when there's none to be drawn?

well thats what standby mode is intended for. problem is that devices in stand by use huge amounts of power to turn on a device like this you switch on manuallly the power switch

As NachoMahma pointed out to me, one big improvement would be automatic reset.

That kind of defeats the purpose. "Automatic" requires that the device be drawing some power in order to monitor the environment, and to respond asynchronously when you (the user) want it. That's exactly what "standby mode" is doing on the original devices, and what this "little gadget" is preventing.

Is there really no for it to detect that without the constant consumption of energy?

you could use a rfid based thing. then it opens some mosfet that otherwise just keeps the thing kinda unplugged but . . . is it really justified ? i think a better solution is to make the standby circuit so minimal and efficient that it takes damn low power (few mW or less). then you can use lower power remote which will use smaller batteries and last longer . . . and be better to the environment you can also store some energy in a capacitor and use it as power supply for the stand by circuit. but if you leave it in stand by for too long the capacitor ends for stuff without remote control - i dont understand why standby mode is needed at all. i think a simple on off switch on the ac in is way better

Wups, sorry...I wrote my reply to you below (dated Dec 2 3:36 PM) _before_ I saw this posting of yours. Your opening paragraph is exactly what I was thinking of. You ask, "for stuff without remote control - i don't understand why standby mode is needed at all." For a Green person, that is the question, isn't it. But many devices have such standby. Your computer monitor, for example. If you don't run an active screensaver, the monitor will appear to "turn off," saving energy. In fact, it's just gone into standby, waiting (and drawing some power) for your computer to send a signal down the VGA cable to have it turn back on. Fax machines, photocopiers, and so on, often have "powersave" states where they go to minimal, but non-zero consumption, waiting for someone to come along and want to use them. The logic is that some of these devices need several minutes to "power up" from scratch, and the standby state increases the convenience for the end user.

the monitor is a good example of thing that could be built better i have a 20 ' ' lcd. quote from user manual : power consumption : on : < 45 W stand by : < 5 W off : < 3 W would i design it i'd make the on off switch a simple switch on the ac in or atleast something that makes the monitor take beow mW 's. the standby - on transition could be done powered entirely thru the vga port so the monitor takes really 0 when in stand by (say bye to the flicking red led) there is also another point where on off switch is better - unplugged (or really switched off) devices dont get blasted from lightning. where i live (mountains in north israel) in the winter there are powerful lightning storms. if you leave electronics plugged in at night you have good chance to wake up to the smell of them vaporized in the morning

That's appalling, that the OFF state still draws 3 watts! This whole "standby" culture in consumer electronics is dreadfully wasteful, as you well know. Sigh... You're right about the lighting problem. Device switches are definitely not designed to handle tens of kV -- lightning current through your AC cord will arc right across the switch and fry everything (yech). Unplugging, or being able to switch off the circuit breaker at the mains, is definitely your best bet.

That's an engineering question, which I'm not competent to answer definitively. It certainly should be "possible" -- for example, RFID chips don't consume power until they're zapped by the reader. Existing devices draw power during "standby" specifically to monitor when you've decided to use them, and the circuitry for that is well established. Making something that didn't do that would require some electronic design.

interesting. perhaps make the remote itself a collection of rfid tags and the tv / whatever the reader ?

Then the TV still has to be powered all the time, and more, it has to be constantly broadcasting the reader signal, "just in case" the remote comes into range.

If you want the TV/whatever to be zero consumption, I think you need something like an RFID chip embedded in it. The remote becomes the "reader", but instead of the RFID using its received power to send back data, instead it uses it to trigger a relay which turns the TV power back on.

Since RFIDs are solid state, I'm not sure this is something a DIYer could hack up themselves.