Most people know about standby power (i.e. that many electronic devices continue to consume some power even when they are turned off). One way to eliminate standby power is to use a power bar or surge protector with a built in switch to turn off connected devices completely, but these are annoying and rarely get used in practice for 2 reasons:

1. Power bars are usually located under desks or are otherwise obstructed making the switches difficult to access.

2. The power bar switch controls all outlets on the power bar, but sometimes it is desirable to turn some devices off while leaving others on.

I build my own remote power switches to solve both these problems. I can turn off just the outlets I want with a switch placed exactly where I want it. See examples of some of my remote switch installations below. If you have enough mechanical and electrical aptitude to drill a hole and solder two wires together, you can make your own remote power switches too.

For information on this and other projects of mine see my website IWillTry.org.

Step 1: Materials

Here are the materials to make an illuminated remote switch. A non-illuminated remote switch is easier but I prefer this style since it provides visible feedback as to the current status of the electronic equipment connected.

The materials are:

Qty - description - cost
1 - rocker switch Digikey part no CH809-ND - $1.24
1 - plastic enclosure Digikey part no HM375-ND - $1.60
1 - surge protector with removable back cover - $15
6ft - 14 gauge 3 wire electrical cord (should have black, white, and green wires) - $5.00
2 - 2" lengths of 3/16" heat shrink (not shown)

1. Most power bars already have an illuminated switch. You could simplify this project by simply relocating that switch remotely, but I prefer to have a remote switch that only controls some of the outlets on the power bar allowing others to be "always on".

2. Costs for Digikey components decrease with quantity. It will also take you less time per unit if you build several at once. I purchased 10 each of the switches and enclosures for this reason.

3. This particular power bar was for a computer, so I used a surge protected power bar. Non-surge protected power bars are less expensive.

Step 2: Tools

These are the tools I used:

Power drill and 15/64 drill bit
Soldering iron
Wire cutters
Wire strippers
Screw driver
Exacto knife (not shown)

Step 3: Schematic

The image below shows a generic schematic for any power bar. The power bar switch and surge protection circuitry are left out for clarity.

Effectively all you need to do is splice the switch (pins 1 and 2) in series with the hot wire (black) that goes to the outlets you want to control. The switch also contains a light. One side of the light is connected internally to pin 2 and is powered by the hot wire. The other side of the light is connected internally to pin 3 and needs to be wired to the neutral wire (white) inside the power bar.

Step 4: Cut the Enclosure

The hole dimensions required for the switch are 28mm long by 13.5mm wide. Scribe an outline with these dimensions on the side of the housing. Then use an exacto knife to carefully cut away the plastic to the scribe line. Check the switch for fit and adjust as needed.

The electrical cord I used was about 1/4" in diameter, but it could be squeezed through a 15/64" hole for a good tight fit.

Drill the 15/64" hole (or whatever best suits your cord) in roughly the location shown. Precisely locating the hole isn't very important.

Step 5: Wire the Switch Enclosure

Cut the electrical cord jacket back a few centimeters at one end.
Insert the cord through the hole you drilled previously. If you cut the jacket at an angle it will make inserting the cord easier.

Strip about 5mm of insulation off of each wire end. Pre-tin the wire ends and switch terminals with solder. Then solder the wires to the switch terminals as shown in the images and schematic.

Once you are satisfied that you have good solder joints and no stray strands of wire that could potentially cause a short, screw the lid onto the enclosure.

Step 6: Open and Inspect the Power Bar

Some power bars are easily opened by removing some screws. Others are not easily opened. They may be glued or riveted closed. When purchasing power bars, look for those than can be disassembled.

This particular power bar is easily opened by removing 7 Phillips screws from the back.

Once you have the power bar open there are a few things you want to look for:

1. Where is a good place to drill a hole through the side for your remote switch cord to enter?
2. Where is the hot wire (black) that feeds the group of outlets you would like to control?
3. Where is a good place to connect to the neutral wire (white)?

See the image below for the answers to these questions for my particular power bar.

Step 7: Drill a Hole in the Power Bar

Once you've decided on the best location for your remote switch cord to enter the power bar, drill a 15/64" hole in that location.

If the desired location is right on the seam where the two halves of the power bar housing meet, just reassemble the power bar before drilling. Be careful not to drill any deeper than you need to.

Step 8: Wire the Remote Switch to the Power Bar

Cut the electrical cord jacket back as much as necessary to have a reasonable length of wire to work with inside the power bar. In my case this was about 6".

Strip each of the three wires in the cord back about 5mm and pre-tin them with solder.

Cut the hot wire (black) in the power bar that you chose in an earlier step.
Strip the two cut ends back about 5mm and pre-tin them with solder.

Slide some appropriately sized heat shrink over the black and white wires of the cord and solder these wires to the black wire ends in the power bar. Make sure the black cord wire goes to the hot side of the black cut wire in the power bar. Likewise, the white cord wire should go to the outlet side of the black cut wire in the power bar.

After confirming good solder joints, slide the heatshrink down the wires over the joints and shrink it. Preferably you should use a heat gun, but you can also use a hair drier or the soldering iron itself (it just takes a bit longer and is a bit smellier).

Solder the green cord wire to the neutral (white) wire inside the power bar at the location you picked earlier.

Step 9: Re-assembly, Testing, and Savings Calculations

Reassemble the power bar making sure your wires are out of the way of all outlets and screw mounts and that the two pieces of the power bar housing still fit together nicely.

It's a good idea as a first test to plug the power bar into another power bar. That way if you inadvertently short circuited anything, you'll just trip the power bar breaker instead of your house circuit breaker.

Try plugging a lamp or other appliance into each outlet and test if you can control the outlets you want. Also check to see that the switch illuminates correctly (if it is always illuminated, then you swapped pins 1 and 2 in the schematic).

You may also wish to label which outlets are "switched" and which are "always on". It doesn't take long to forget.

Savings Calculations
Let's assume that an average remote power switch installation eliminates 15W of standby power. Assume further that the equipment is in use 40 hours a week (an office computer setup for example). Therefore, there are 128 hours a week when the equipment would normally have been in standby mode. That corresponds to 99.84 kWh per year. At roughly $0.07 per kWh (the price where I live), that is a savings of about $7.00 per year.

Therefore the time till payback on materials alone is at least a couple years. It's probably 5-6 years if you value your own time at a reasonable rate. But it does pay back eventually, and if you are running a lot of equipment (for example if you have a home business) the savings start to become significant.

There's also the convenience and coolness factor of turning off multiple pieces of equipment with a custom mounted illuminated switch. Honestly... you'll be surprised how much fun you'll have turning your equipment on and off once you install one of these switches.

For information on this and other projects of mine see my website IWillTry.org.
I find out this product at Amazon, this works just great! Watchdog timers, grouping for the outlets for reboot/timers. Everything you need in a fancy pants power strip. Only lacks power usage monitoring, and environmental probes. And would be great if it did my laundry, but alas it only saves me truck rolls. <a href="http://www.thebestsurgeprotector.com/simran-sm-60-110v-250v-universal-3-outlet-power-stripsurge-protector-for-worldwide-travel-with-overload-protection/" rel="nofollow">Good article</a>!
they should just make a rechargeable CMOS battery so when the computer is on it gets charged
Overall, this is a good idea, however, there are a few issues with killing all power to electronics that should be remembered.<br/><br/>1. computers : if i recal correctly, the BIOS battery is only under load when the computer is unplugged. Therefore, killing power to the computer would shorten the life of the bios battery (which is needed for power outages, upgrades, and moves) a dead BIOS battery can be a real bummer when they're soldered in, or in an impossible clip, and your power goes out<br/><br/>2. stereo equipment - on most equipment, clocks and presets are dead without standby. if not, your running a battery (or using non volatile memory, which is rare). In the long run, you're creating hazardous waste by killing batteries prematurely. <br/><br/>3. TV - say goodbye to channel programming and time. I'd hate to reset those everytime i wanna watch tv.<br/><br/>4. everything else - wall warts / cheap transformers are your biggest waste, in my experience... separating those out and switching only those would save almost as much electricity (imho) without the frustration... unless you have wall-warts for any of the above devices. the best solution would be a less wasteful transformer to replace all your wall-warts... I'll see what I can do... ;)<br/><br/>further wall-wart info (and warnings) <a rel="nofollow" href="http://www.glitchbuster.com/wallwart.htm">http://www.glitchbuster.com/wallwart.htm</a><a rel="nofollow" href="http://www.glitchbuster.com/wallwart.htm">http://www.glitchbuster.com/wallwart.htm</a><br/>
CMOS backup batteries typically have a life of many years (up to 10). Unless it's a realy old computer replacing this battery is a minor task.
We keep the DVR cable box plugged in and cut the power to the TV with no time or programming issues. I have 1 very old TV that does have to reprogram when I turn it on, another TV also old does not have that problem. I use a clock for time, never use the TV for that.
Just curious, is it mandatory on the internet now to point out flaws on everthing, even when most likley those flaws are irrelevant and do not need to be pointed out? I can't remember the last time I saw an electronic based instructable or otherwise without someone telling everyone not to do it (in so many words) Ugg, just let it alone man!
What;s your problem. I for one thought that gschoppe was very helpful.
dude... i commented almost a year ago... talk about bumping old posts... however, I stand by my statements. I didn't, as is common, say "d00d dis projekt iz stoopid!", I in-fact have a very similar device attached to my OHP digital projector to control the LCD and lamp together. (built before this instructable came out) however, I think a straightforward discussion of pros and cons should be welcome in any situation where a change is suggested, especially a "green" change. Not clarifying those pros and cons yields a lopsided view of "consensus", and can confuse people interested in researching the change. In the past year, I have seen many articles warning of the "gluttonous" standby consumption of many electronics, and urging the reader to unplug... none of these articles seem to note that most standby consumption is minimal, and has a purpose. In an open comments venue, I felt (and still feel) that this information would be constructive. Making an informed decision before investing in a change is the heart of true "green" living, and too many people forget that... Its not about forgoing every convenience and living in a cave because the news told you to, its about deciding what cuts can be made to help protect the earth, with acceptable impact to your quality of life. To make such a decision, you must know the impact. BTW: the original poster replied in a well thought out manner, as to why it made sense for his lifestyle... Kudos to him, as that gave more information to those considering the change. Do you see how this is a positive thing yet?
Good point about wall warts, but keep in mind that they are NOT all created the same. Specifically there are transformer based warts and electronic warts. FYI, the electronic ones are very light weight - they feel like feathers compared to the old transformer ones. My cell phone's electronic charger has been plugged into my Kill-O-Watt for 163 hours now and pulled a grand total of 0.00 kWH! Given this massive :) energy consumption, I am not really worried about leaving it plugged in all the time. My TV now... I wonder if I could add a battery and charging circuit to maintain time, channels etc, when I cut power? Computer CMOS batteries are under load when the computer is off, but it is a very small load. I can't give exact numbers but I can say that I've had computers turned off for months at a time without draining the CMOS battery!
Regarding your first note about the CMOS battery of computers: most Desktops use a CR2032 watch battery, which you can buy for $1-$2 dollars and typically are very easy to replace (just a matter of opening the case, typically using a flat-head screwdriver to pop out the old, and then pop in the new). However, you are correct that the battery can be a bummer if it dies--especially on newer machines. The battery allows the motherboard to retain it's basic settings (it's BIOS settings) without any external power. These settings on newer machines often contain the CPU and Memory speed settings, as well as settings that dictate if the machine will expect to see a 3 1/2" drive at boot. If the settings revert to default (which is what happens if the machine has no power and a dead CMOS battery) then it's very possible that your PC will underclock your CPU and Memory (i.e. will make the equipment run at a speed slower than what it is capable of or rated for). Fixing these settings can be a scary task to the computer novice, and can sometimes require removal of the CPU itself to verify the model number so that the proper settings can be researched.
I LOVE the manufacturers that use CR2032s or 2016s in a simple clip. however, I've worked on at least 5 computers in the last year (I'm a technician) that were barrel cells, despite being relatively new machines. what's worse is that at least 3 had the cells soldered directly to the board, with a really tiny dot-pitch. Its still an issue, albeit most often with offbrand, budget PCs... or palm PDAs, or iPods, or........ oh, was I rambling, sorry, I get like that... </rant>
even worse the barrel cells leaked goo onto the mobo rotting it out another coppermine goes to the dump :(
you can do on an old transistor radio.....
Good points all around. Some had not occurred to me because they simply don't apply to me. 1. I do keep my computers plugged into the "always on" outlets and only switch off the peripheral devices (printers, speakers, monitors, etc). 2. I have no presets on my stereo equipment. 3. I don't watch TV (who needs all those commercials). I only watch DVDs. 4. I've also replaced all my unregulated AC/DC transformers with switch mode supplies from Digikey. The payback time I calculated on the cost is about 5 years, but I wonder about the waste. Can old unregulated AC/DC power supplies be recycled? Finding someone else who could use them kind of defeats the purpose.
Iwilltry; great idea and your submission is well written. But I'm concerned about safety (and potential liability for those who aren't versed in electrical engineering). This mod is definitely not IEC code compliant. Specifically, you need to either use a UL-listed switchbox and conduit for your remote switch, OR as some others have suggested, switch the load with an appropriate relay or solid-state switch (TRIAC) controlled by a low voltage control circuit. -G
You could replace the switch with a an inline fuse and a 10Amp Relay with a 12v coil, powered by your PC's 12V from the power supply. That way, when you shut down the PC, the peripherals go off automatically. It's what I did with my setup! ;-)
That's an awesome idea. I might try it myself. Thanks for the idea!
Still a cool instructable, btw. :-)
Nicely explained instructable and a good idea. I am going to sort out my home video equipment. I will use a simpler method though: I will use two power bars with one of them plugged into a wireless remote control switch. BTW: They use neons with a series resistor in illuminated switches. You can't connect an LED directly across live and neutral without frying it!
I didn't know that about the neons. I assumed they just used an LED with a series resistor and that it only lit on the positive cycle of the AC. But now that I think more about it I guess it might fry due to the high reverse voltage on the negative cycle (not sure what reverse voltage LED are typically rated for). Thanks for the tip. I'll update the instructable.
A typical LED would have reverse voltage rating of only 5 Volts.
It depends. Some LEDs have a reverse voltage of 2x their forward voltage. Some it's half. Some it's more or less. It all depends on who manufactured them.
I have a similar setup, only that mine is built into my computer desk.. When I am through with the computer I just turn my switch off and it turns off power to every thing including two computer systems. Wanted to add image but camera batteries went dead. Will post image later.
Instead of tinning the ends of the wire, all you would need to do is get a few quick connects and crimp them onto the wire. Then connection would be easier if you aren't too sure of yourself in using a soldering iron.
This is really neat. I just did something like that in my workshop. A switch on the desk turns the lamp on. The switch for my is mounted on the desk.
but when the tv gets turned off it flips through all the channels and makes you wait 1 WHOLE MINUTE BEFORE WATCHING TV. plus the clock inside doesn't work when its not on and WHAT WOULD HAPPEN IF ALL THE CLOCKS STOPPED WORKING!!!! AUGH!!! I really dont like waiting plus i dont liek changing to channel 99 just to see what time it is. but i guess it would save power and with the power you save you could run a clock!!! then no more changing to channel 99!!! YES!!!!
Thanks for the Instructable!. I used your example and used a simple 6 outlet surge protector and relocated the existing rocker switch to the remote position.
Excellent. That's the simplest solution as long as you don't want any of the outlets to be "always on".
Neat! I always hafta stick my power bars in awkward, stupid places, cuz wifey don't like lookin' at all them cords and plugs n' such. Also, the power bar usually comes with a stoopid short cord (to keep those dinks that plug fifteen different high current doodads in there and use 'em all at once, from a' burnin' their houses down) Now, I can hide the power bar, and put the switch wherever I damn well please. Also, I can use up some of the old coffee maker power switches, I've accumulated over the years.
cool! but for my pc (and other stuff) i run a Belkin SurgeMaster (the one you put under your monitor) <a rel="nofollow" href="http://images.google.com/imgres?imgurl=http://www.provantage.com/HW_70673.GIF&amp;imgrefurl=http://www.provantage.com/surgemaster-home-series-power-strips~22070673.htm&amp;h=151&amp;w=151&amp;sz=5&amp;hl=en&amp;start=1&amp;um=1&amp;tbnid=KBo-6pglBC-J-M:&amp;tbnh=96&amp;tbnw=96&amp;prev=/images%3Fq%3DSurgeMaster%2BHome%2BSeries%2BPower%2BStrips%26svnum%3D10%26um%3D1%26hl%3Den%26sa%3DG">http://images.google.com/imgres?imgurl=http://www.provantage.com/HW_70673.GIF&amp;imgrefurl=http://www.provantage.com/surgemaster-home-series-power-strips~22070673.htm&amp;h=151&amp;w=151&amp;sz=5&amp;hl=en&amp;start=1&amp;um=1&amp;tbnid=KBo-6pglBC-J-M:&amp;tbnh=96&amp;tbnw=96&amp;prev=/images%3Fq%3DSurgeMaster%2BHome%2BSeries%2BPower%2BStrips%26svnum%3D10%26um%3D1%26hl%3Den%26sa%3DG</a><br/>which it gives you a Main switch, a Computer switch, Monitor switch, and 2 aux (anything) switches. it is very useful!<br/>
I like this, but wish you had shown your "split" version - you know: some on, some off - for us newbies. Also, the problem with turning off TVs and VCRs completely is losing all the programming. That flashing 12:00 drives me crazy.
This is the split version. The group of 5 outlets is controlled by the remote switch. The group of 3 outlets is always on (or rather all outlets are still controlled by the switch built into the power bar. I updated the instructable to make this more clear. Thanks for the input. The blinking 12:00 drives me crazy too, but a little electrical tape does wonders ;-)
I've got a Dell like that at work. L

About This Instructable




Bio: I have a B.A.Sc and M.Eng. from the University of British Columbia, specializing in electromechanical design, but mostly I like to tinker ... More »
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