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The other day I was very excited to discover an illuminated switch at Radioshack that was roughly the correct size, shape and action as a standard guitar pedal push-button switch. This is great for pedals because the indicator of whether or not the guitar effect is on would be built directly into the switch, eliminating the necessity of excess drilling and wiring.

True, the model switch that I bough is an SPST switch, which is a less-than-ideal replacement for the usual DPDT bypass switch. Nonetheless, I figured that I could make it work as a guitar bypass switch by having it control a simple DPDT relay.

I was about to wire it all up into my newest guitar pedal when I realized that this switch actually required 120 VAC to illuminate! What's up with that? This bugged me a great deal as I would be working with low-voltage DC, not high-voltage AC. This was not going to do.

I immediately resolved to replace the little bulb inside with an LED. This required a near total dissection of switch, but after a little figuring out, I am happy to report that the mission has been accomplished. Follows is a method for converting an illuminated Radioshack switch from 120VAC to 3-12 VDC.


Step 1: Go Get Stuff

You will need:

An illuminated Radioshack switch (#275-671)
An LED
A 100 ohm resistor
A zip tie
A soldering iron setup
A flat head screwdriver
Wire cutters
Pliers

Step 2: Take It Apart

Use your screwdriver to bend back the metal tabs on the bottom that are holding the unit together. Carefully remove the black plastic mechanism from the bottom such that it is left in one piece (the springs and levers shouldn't fall out of it).

Next pull out the white non-conductive plate, the hollow cylinder, spring and plunger.

Remove the clear cap from the top.

Step 3: Clip the Bulb

Use wire cutters and clip the bulb away from the top of the cylinder, leaving as much wire as possible still attached to the switch.

Step 4: Add a Resistor

Remove their 330K ohm resistor and replace it with a 100 ohm resistor.

Step 5: Wire the LED

Wire the LED in place where the mini light bulb used to be.

Step 6: Put It Back Together

Carefully reassemble it. It should be more or less like the way you found it.

Press the metal tabs back in place with your pliers.

If it is still a little loose, wrap a zip tie tightly around the bottom of the casing.
Yes, I would have put a little heat-shrink tubing on the LED's legs too. However, very good 'ible, and kudos on the great close-up photography. You must have a good camera.
I agree about the (de)evolution of Radio Shack. DigiKey is a good source of components. They have pretty much anything and much of it is pretty decently priced. I have not recently ordered anything from them so I'm not sure if they have minimum orders or how much shipping is. For those of you in the Chicago or Milwaukee areas, American Science and Surplus on is a fabulous source of everything from rubber chickens to telescopes. I go to the Milwaukee store every time I travel there. http://www.sciplus.com/ In the Twin Cities of MN, Axman Surplus is the place to go. They have similar sorts of things as AS&S. I am there every couple weeks just to look at stuff even if I am not working on a project. http://www.ax-man.com/
<br /> This will invalidate your warranty therefore is dangerous<br />
i will assume this is sarcastic humor because voiding a warranty can be as simple as breaking a sticker.
hmmm... not sure I agree with frenzy here. If we assume he is correct: invalidated warranty == dangerous Then we need to shut down instructables.com, cause 80-90% of this site invalidates warranties!!!
More like 94%. The whole pourpose of this site is basically different ways to void warrenties and make things look cool as you do it.
If I'm adapting a switch for use in another [low voltage] application. I don't really care about the warranty. I have never used warranties on switches I buy anyway, they are cheap, if they fail I just toss them out and buy a new one.
Nice job, much nicer than the separate LED normally used. And it looks like you fumbled the switch at the end of your vid. Funny :)
Co-incidentally, I published an Instructable early today that uses the same switch. In my case I needed a SPST 115./230 volt switch capable of handling 10 amps. I did not need illumination when the circuit is active and chose not to mention that feature in <a href="https://www.instructables.com/id/Replacement-Switch-Craftsman-Radial-Arm-Saw/" rel="nofollow">my Instructable</a>. I used the switch to control my radial arm saw after the factory switch was no longer available.&nbsp; When I need to control line voltage for a tool, I am equally dismayed that so many otherwise suitable switches are for low voltage and low current.
Radioshack is apparently out of touch with everyone's needs! That store frustrates me.
I live in Denton, TX and over in carrollton is a store called Tanner's Electronics and they sell a plethora of parts at an awesome price. a 7805 at radio shack is $5 but at tanners its only $1.49. I really dislike radioshack but for need now stuff its all I got.
I live in the UK and we have something similar to Radioshack called Maplins - it was once a pretty competent electronics store, but now all it does is stock &quot;electronic&quot; toys and PC parts; whenever I look something up in their catalog they say it's not in stock, they only have one of them or the have discontinued the item, which is possibly more common than air! That's why I switched to Farnel years ago although it's such a shame to not be able to walk into a shop and physically get what you need... Saves petrol though :P
I do not know about things in the UK, but in the USA magazines for electronics hobbyists have pretty much disappeared. Certainly there are market driven reasons for that. But, it is too bad people are not encouraged to learn about electronics and experiment with it through such magazines. it may be only my biased observation, but it seems Radio Shack moved more toward toys and stocked fewer things for experimenters about the same time the magazines disappeared. One bright spot is the interest in building robots.
Have you heard of Elektor? (www.elektor.com) it's a very good magazine and is available in the US :) but yeah i totally agree with your point about the fact no-one is encouraged anymore :( James
me dos.
well done mod, and tanners rocks! its like disneyland for diy'fers.we should all support family owned shops like theirs instead of big corporate, big mark-up conglomerates
Awesome! Finally a [questionably] cheaper alternative to those impossible-to-find dpdt guitar pedal stomp switches!
Not cheaper at all since you also need to get a relay :-)<br /> <br /> Small Bear Electronics and Mouser both sell them for a reasonable price.
You should have insulated the LED's legs, even if it's low voltage, you don't want it shorting out on anything... :) Nice mod, I'm often looking at LED-based illuminated switches for use on mains supplies, it'd be nice to do, if I ever needed one, which I might, I'll find a reason to want one... :P
great !!!
Thank you very much. I was not aware of the voltage needed when I bought the switch but soon, everything will be good.

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Bio: My name is Randy and I founded the Instructables Design Studio. I'm also the author of the books 'Simple Bots,' and '62 Projects to ... More »
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