Introduction: Eliminate Standby Power With a Desktop Power Switch!

Picture of Eliminate Standby Power With a Desktop Power Switch!

We all know it's happening. Even when your appliances (TV, computer, speakers, external hard drives, monitors, etc.) are turned "OFF," they are still actually on, in standby mode, wasting power. Some plasma TVs actually use more power in standby mode than they do when in use! About 13% of household energy use is from appliances in standby mode. It has been estimated that Americans spend around $4 billion on standby power every year. Generating the electricity for appliances in standby releases 27 million tons of CO2 into the atmosphere (every year).
Seriously, standby mode sucks (power). So I decided to help out. By re-wiring the switch from the power strip under my desk up to a box on top of the desk, it is now easily accessible. Every morning I turn the key to deliver electricity to my computer, hard drives, speakers, and monitor, and every night, I turn the key the other way, cutting power to my appliances, thereby foiling their attempts to raise the energy bill. It works great! Please comment, rate, and VOTE!

Step 1: Supplies

Picture of Supplies

Many of the parts I used are interchangeable with other similar parts. These include the type of switch, LED, project box, etc. If you want to be boring, you could just re-use the switch and LED from the power strip.

- Power Strip with LED indicator (that you don't mind hacking up a little)
- Key switch (Jameco #106650)
- 3 mm LED
- Small project box (Radioshack catalog #270-1801)
- Cable wrap (Jameco #1585531)*
- 115VAC-capable wire*
- Relatively thin wire for LED*
- Small heat-shrink tubing
- 2 small zip-ties
- Thin metal plate (fits where switch and LED were on power strip)
- Velcro strip
- Gorilla Glue and/or superglue
- Electrical tape
*needs to be long enough to go in between power strip and box location

- X-acto knife
- Soldering iron w/ solder
- Heat gun
- Wire cutter/stripper
- Desoldering pump
- Dremel
- Tin snips
- Large-ish clamps
- Drill with various drill bits

Step 2: Start on the Box

Picture of Start on the Box

Begin by mapping out where you want your cable wrap (where the wires go in/out), LED, and switch. I put my cable wrap hole out the back center, my switch centered on top, and my LED in the upper right corner. I suggest marking where to drill by spinning the tip of an X-acto on the box. This helps guide the drill bit and provides a good visual reference. After marking the holes, hit 'em with the drill press, then make sure everything fits before moving on...

Step 3: Commence Soldering!

Picture of Commence Soldering!

We'll start by preparing the wires. If you used a computer power cable like me, the first thing you'll want to do is cut the ends off, strip away about an inch of outer insulation, then about a 1/4 inch of individual insulation. You should also strip the ground cable (ignore the contradictory image note). Do the same thing to both ends of the cable. For now, we will only be using one end of the 115-volt cable. On that end, apply a generous amount of solder to tin it. Then insert the wires into the barrel connectors on the key switch. While heating up the connectors with your soldering iron, apply solder to the wires where they contact the connectors. Also, attach the ground wire to the switch's metal casing. If something fails, this will protect you from electrical shock.
For the LED wires, strip about 3/8 in. off one end of the set, and about 3/16 off the other. On the long side, solder on your LED, but not before you slide heat-shrink tubing down. I forget to do that every single time.

Step 4: Box Assembly

Picture of Box Assembly

Now we will put everything in the desktop box. Start with the switch by threading the wire through the hole, positioning the switch, then firmly tightening the nut. Before installing the LED, you may need to cut away any ridges in the box with a Dremel to allow the LED to sit flush with the inside of the box. Then clean out the box of plastic shavings, insert the LED, and superglue it in place. Give it some time to dry and collect its thoughts.
After the glue dries, put the wires through the cable wrap. It might help to wrap both ends in tape to keep them together. Next, feed some cable wrap through the box and zip-tie it in place on the inside and outside. Schweet! Your box is done!

Step 5: Hacking the Power Strip

Picture of Hacking the Power Strip

Before we solder the box's switch and LED to the power strip, we need to take out the switch and LED it already has. Find and unscrew all the screws in the power strip and open it up. If you bought a cheap power strip, the circuit should be pretty straight-forward. Examine the circuit and follow the tracks to figure out what each of the contacts on the switch does. You also need to find the LED.
Desolder all the wires from the switch contacts, but remember where they go because you will be putting them back later. Next, desolder the switch itself and remove it from the power strip. Then desolder the LED, making note of polarity on the circuit.
After the switch and LED are removed, feed the wires coming from the desktop box in through an open hole in the power strip's casing (like where the switch was). Solder the proper wires in the proper places. New switch wires where the switch was, new LED wires where the LED was, and switch ground to the power strip's ground. After soldering, position the circuit board where it was and close the power strip's casing back up. Test your modification by plugging the power strip into the wall, and a simple light into the power strip. Turn it in and off with the switch box, and try the light in all the outlets. If it works (it either does or it doesn't), move on. If it doesn't, examine your wiring and circuit board. If you comment with a picture and your issue, I may be able to help.

Step 6: The Little Metal Thing That I Can't Come Up With a Name For

Picture of The Little Metal Thing That I Can't Come Up With a Name For

To keep the cable wrap in place, and keep everyone else away from massive amounts of current, I figured I'd add a little metal piece to go over the open holes. You can use, metal, plastic, or maybe wood (but wood catches on fire). Cut your material to fit over any open holes. I made mine extend to the end of the power strip so it looks a little cleaner. Then cut a notch with a Dremel that the cable wrap will rest in. If you make the notch just right, it will sit in between corrugations in the wrap, locking it in place. Verify the proper fit, then apply small amounts of Gorilla Glue to the power strip where it will go.
Clamp the piece down evenly and let it sit for a few hours to dry thoroughly. Once it's dry, set up your new, improved anti-standby power strip!

Step 7: Secure the Area

Picture of Secure the Area

To secure the desktop switch to the desk, you probably want to use Velcro strips. Put one part on the bottom of the switch box and the other on the desk where you plan on placing the box. I put mine right next to my computer. Easily accessible, but out of bumping distance. Before you plug in all of your stuff, test it out again with a light. If it still works, plug in your stuff and try it out!
w00t! You can now easily turn on and off your power strip and stop your appliances from eating up electrons! Fight the power! Comment! Rate! VOTE!


DaryleTilroe (author)2015-07-30

I know there is a "be nice" comment policy but I happened across this project and it really should be pulled. It is a complete liability risk for instructables and there are several safety problems and design defects. As a Professional Electrical Engineer I have a responsiblity to comment and warn.

Just off the cuff:

-Hacking into a line voltage, CSA/UL certified device like a power bar violates that certification. Should your house burn down and the cause be traced back to this hack your insurance coverage would be in doubt. I know there are probably alot of other alterations on instructables that fall into this category but with the deceptive simplicity of this project and the defects below I think it is a higher risk than most.

-You are pulling a cable out of a 15A rated device to ta 3A rated key switch in series. If you look closely you will notice the powerbar switch being replaced is rated 15A.

-The hole cut in the power bar has an ungrounded metal filler panel, no gromment/strain relief.

-Cable may be a suitable current rated line cord but that is not emphasized and it is guarded by simple wireloom in an exposed area.

-Run to switch and metal switch is *UNGROUNDED*.

-Current limiting and wiring protection/strain relief of LED wiring is questionable.

In summary this is a cute idea but the implementation has several design defects and risks to the unwary.

charlieb000 (author)2013-10-24

not LOL.... This guy forgot to connect the MOST important wire. The earth wire should connect to the exterior of the switch he is using. This will provide infinitely greater insurance against electric shocks.

DIYByKev (author)2013-06-14

Nice! But isnt it dangerous to play with that much of voltage?

Gaark (author)2011-06-28

To be totally honest, every time I see an instructable messing about with mains voltage I feel real fear.

Whether it's 115V or 240V please please be bloody careful. A shock does NOT feel good, and I say that from experience unfortunately.

teslapulsa94 (author)Gaark2013-02-07

that when the smart child goes and grabs a new cord lol

curious youth (author)Gaark2012-03-01

i agree! shocks are well shocking lol australia and its 240 volts lol

still gunna try this though bahahaha

Gaark (author)curious youth2012-03-05

Makes for a great hairstyle though!

XboxModz (author)2012-03-22

This is actually NOT a good idea to use with a PC. Reason being is when you cut off the mains to a PC, the CMOS battery on the motherboard has to kick in to keep your PC clock set correctly.

Under normal circumstances, a CMOS battery lasts for years because it is only used when there is no power to the tower, like during a power outage, but with this setup, you will drain it much faster as it is being drained for 8 or so hours every night. You will almost negate your savings on the electric bill with the cost of replacement CMOS batteries. They aren't cheap.

lukestanmore (author)XboxModz2012-06-08

Surely it's just as bad as flicking the switch at the wall? And A LOT of people do that... (author)XboxModz2012-05-23


Tinworm (author)2009-09-29

I don't get it. What's wrong with just turning everything off at the wall?

mettaurlover (author)Tinworm2009-10-03

doing that's less convenient for us lazy people.

Tinworm (author)mettaurlover2009-10-04

are you serious! No disrespect, but is it really worth all the effort of making your control box to save yourself the hassle of walking to the wall and switching off at the mains!

omnivaal (author)Tinworm2009-12-25

Thats fine if you're outlet is easily accessible. My power board is screwed to a block wall behind the desk the PC is on. No way am I crawling on hands and knees under the desk twice a day to switch my computer on and off.

Tinworm (author)omnivaal2009-12-25

That's fair enough. I guess you are in the US, where I think domestic wiring is different?

It is a very tidy bit of design. I like it.

I just didn't understand it, and I do now. Here the mains switch is next to the plug, so you stick an appliance (or and extension if the appliance is inaccessible) in the socket on the wall and flip a switch.

That said, I have power running to mine all the time, even when the PC itself is off (which I know is wasteful).

In the case of a PC which won't boot down because of some crash or sometjing freezing, my PC comes with a kill switch on the back (and I have my tower mounted on the wall sideways, so that I can reach everything on the back and on the front.

Best Wishes, omnivaal

mettaurlover (author)Tinworm2009-12-26

Actually, in most cases we choose to have our power blocks in that location. It makes for a much less cluttered workspace. Replacing the manual switch with a key switch is actually a better idea than leaving it; if you don't, you might accidentally cut power to your appliances, in my case a computer.

I just put everything on a few remote controlled sockets in my bedroom and when I go to bed, I just press one button and my whole room is pretty much turned off! :)

That's a really good idea (4 us lazy peoplz or people who like to have convenient electrical control). But isn't it bad to have more than a few things plugged into one outlet? A fire hazard? Hmmmm... well, I guess I DO have 10 things plugged into one socket... (2 computers, a fan, a monitor, a printer, 2 pairs of speakers, 2 wireless routers, a backup battery for the USP this is all plugged into, and I guess 11 because sometimes my iPod is plugged in...) Meh, nevermind... But still, its a good idea...

mettaurlover (author)account3r22012-03-21

And... You just necro'd a thread that was left to die over a year ago.

danielemur (author)2010-06-21

Not to be rude or anything but what is the difference between turning the devices off with a key or switch? Or am I just missing the point of the project?

I chose to use a key switch because normal toggle or rocker switches could be bumped on accident. the key still is a switch, but it is a "safer" type.

Maybe you could have 5 toggle switches all going to the power strip facing opposite directions for every other one so that you have to turn all of them off the opposite direction of the on position so it is more confusing and more expensive to make and use.

Like this:

\/ /\ \/ /\ \/

The arrow-type things are the direction of the toggle switches.

That makes sense. Thanks for clearing it up!

Revanchist (author)2012-03-02

Oh I love it! You sir have given me a great Child lock idea! If I want to block access to TV or a video game console or any electrical equipment all I have to do is turn the key off!! this is awesome! thanks!!!

jesusaguilar6194 (author)2012-03-02

is it just me or does that lock only have one pin

JSUTHERLAND8 (author)2012-03-02

This is a lot of work. I just mount my power bar in a place where I can reach the Switch. The little Key switch used on the remote of the power bar should be rated at 15 Amp, with wire to hold the same Current.
I find my modem to take the most power when not in use, it has no standby mode and takes many minutes to reconect if it gets powered down.
Some Computers use the standby power to offset the battery power, so the few cents you save on AC power may cause a bigger cost in battery replacement.
The one computer desk I have has a split power bar built in, 1/2 is switched at the front, and 1/2 is live all the times. This is handy to turn off speakers and printers that do not need to be on all day.
Your Idea is good, and saving energy is good. The use of splitloom for 110 volt wire protector, not so much as far as UL and CSA. Keep it safe.....

DarkStarPDX (author)2009-05-11

I would just make a short note about the keyswitch only being used on a maximum of 3 amps (or 360 watts in N.A. --- volts x amps = watts). A lot of computer power supplies are now exceeding this wattage alone, without the monitor connected...

HexKrak (author)DarkStarPDX2012-03-01

I totally agree. This is a great little project, but the switch you're using is going to melt one of these days, and could possibly cause a fire.

I would use a relay rated at least 10A (2300W where I live) and the relay would have a mains coil so it uses no standby current :)

DarkStarPDX (author)DarkStarPDX2009-05-11

Yikes! I just checked the specifications on the Mac Pro and it pulls 12 amps. That is a lot more than 3 :-)

frollard (author)DarkStarPDX2009-05-14

12 amps at 12 volts - you need the amps at 110v (likely around 2 or 3) volts times amps are watts - so the mac is 150 watts... divide by your voltage of choice to get the amperage.

DarkStarPDX (author)frollard2009-05-23

I just double-checked the Mac Pro Tech Specs ( and a little down the page it actually states that the current is a maximum of 12 amps in the low-voltage range (100-120 volts).

So, the Mac Pro utilizes a maximum of 1,440 watts given the nominal voltage where I am (Oregon) is 120 volts.

frollard (author)DarkStarPDX2009-05-24

low voltage range is not 110 :P 12 amps is what a space heater pulls. 15 amps on a 110 volt line is indeed ~1500 watts. Computers usually ship with a 200-300 watt power supply (peak). High end gaming systems push 700 watts...rarely 1000. 1400 watts would frankly catch fire :) That must be a typo. It is true that you will pull half the amps at a given wattage by doubling the voltage...but that is just way too much power for a computer, even a mac pro.

dark sponge (author)2009-05-28

Project boxes are evil.

conrad2468 (author)dark sponge2009-08-10

YOUR EVIL! project boxes are my LIFE!

dark sponge (author)conrad24682009-08-10

Then good job at killing the planet! Plus, no true geek uses them. We use altoids tins, cases from broken stuff, or don't even use a case at all.

Several things: 1. It's spelled g-3-3-k. 2. An altoids tin wouldn't work because they are metal, and besides, they're too small anyway. 3. I don't have any cases from broken stuff because I take good care of my stuff. 4. Not using a case would kinda expose you to 120VAC and several amps.

1. I spelled it that was so he could read it. 2. It's easy to cover it with something (like tape) to insulate it. 3. So does that mean your computer from 1994 is in perfect condition and you still use it? 4. There are projects that don't use 120v. Microcontroller projects (<5VDC) look cool without cases.

vanweb (author)dark sponge2012-03-01

Ummmm... Is not Electrical tape just made from Plastic and dead horses? (melted down into glue) ....

1. Fair enough ;) 2. I wouldn't feel comfortable trusting my computer to some tape. 3. I don't have a computer from 1994. Partly because I'm 14, also because I'd rather have an Apple II. 4. I thought we were talking about enclosures for the switch. 5. Talking like this is kind of fun.

1) I like safety because ive shocked the piss out of myself too many times 2) I was born in 1994.... 3) lists are cool! 4) spst switches are badass...there like chuck norris...there is badass chuck norris and 5) we all know you didnt spell it that way so he could read it you were just too lazy to move your fingers an extra centimeter....

dark sponge (author)conrad24682009-08-10

1. Me too! 2. So was I! I just happen to have a computer from that year because someone gave it to me. 3. I agree! 4. I agree! 5. Maybe you're right on that one, but I can tell you're too lazy to use spell check. Ever notice that squiggly red line under your words?

conrad2468 (author)dark sponge2009-08-10

1) i use spell check....i only use it on the words that are a major mistake like "centameters" 2)i think i may have had a computer from 1994...too hard to tell it looked like all the other bricks... 3) No squiggly red lines so far! 'cept for centimeter and 'cept 4) I'm adding "'cept" to the dictionary. 5) I love parentheses (WOW I SPELLED THAT RIGHT THE FIRST TRY!!!)

dark sponge (author)conrad24682009-08-11

1. I was talking about the way you spelled "didnt". I don't know about you, but in my comment box it puts a squiggly red line under it. 2. Someone needs to add the word "Instructable" to the dictionary, you would think they'd have done this already! 3. Parenthesis are fun (Of course they are!)

conrad2468 (author)dark sponge2009-08-11

1) I use "didnt" a lot so I "dont" bother adding the little semi-quotation marks to them. 2) I just added instructables to my computers dictionary! just right click and hit "add to dictionary" 3) i have a mac so i dont know if you have that option 4) I am also too lazy to capitalize my i's but i occasionally do so.

1. Just added it to my dictionary as well! Mac buddies! 2. I have nothing else to add.

1. :) 2. I didn't actually mean this particular project, just projects in general. 3. I'm 14 too! Someone just gave me an IBM Thinkpad from1994. 4. I thought we were talking about projects in general, sorry for the misunderstanding! 5. I have to agree with you on that!

Not if you insulate everthing with heat shrink (lots of it!) and lots of insulation tape and proper grounding for everything metal

Well...I use them and ive built some pretty *ahem* damn cool things in the past! But thats just opinion i know im not a 100% "g33k" but i still consider myself one...

conrad2468 (author)2009-08-10

great way to restrict your kids computer you need to make an electronic timer....

About This Instructable




Bio: A Bay Area native interested in electronics, mechanics, and robotics, and automobiles. Formerly the electronics captain of Team 100 in the FIRST Robotics Competition, I ... More »
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