Switch

[mpm32]

I'm doing an LED project and I am trying to design a switch for it.

It will be a 2'x2' box 6" high with a plexi top. I ordered 5m smd5050 rgb flex led light strips.

I will install the light strips on a board and install that with the lights facing up into the box 1" below the plexi top.

Here's where the switch comes in; I want the lights to turn on when the box is stepped on.

I have thought of a couple of ideas.

   - just mount an arcade button into the plexi and step on that to get the lights to turn on

   - mount an arcade button switch or leaf switch inside and somehow make a rod the extends out of the bottom slightly that activates the switch once the box is stepped on.  I'd like to go in this direction but the rod would need to hold up the weight of the box so it doesn't trigger until the box is stepped on. Springs and such would be used but I'm stuck on the implementation.

   - make a switch out of some brass shim stock that I have.

Any other ideas?

[yotsuya]

I like your way of thinking...

[Le Chuck]

Seems to me you could browse a bunch of DIY DDR Pad builds and get a good take on what's doable.

http://blog.allthingsgeek.com/article/index/index/id/5/page/1#.UYnVzcrc92o

http://www.inventgeek.com/projects/dancepad1/OverView.aspx


Or just think about the last ten years of war news coverage and build a simple pressure plate like what is commonly found along the scenic roadways of the middle east.  Two metal plates with an insulated spring separating them. 

[Ond]

Build your 2x2 box with a rebate around the inner edge the same depth as the plexi. Drill holes in the rebate near each each corner to accept a rubber grommet.  The grommets sit slightly proud of the rebate by a small fraction of an inch.  Then place the plexi into the 'frame' and use a very slight flex in the plexi itself to trigger thin contact strips (or micro switches) on at least two inside edges .  Use at least two switches in parallel to ensure triggering regardless of foot placement. 

Go a step further, Wire two or more Led "looms" to separate circuits i.e. one per switch and get different colors lighting up depending on where you stand! 

Use a  diffusing material (thick PVC) below the plexi to get a smooth, even diffusion of light.

This of course assumes the plexi is reasonably springy and will tolerate repeated (but a very small) amount of flex without cracking.

[mpm32]

I like your way of thinking...

Very close - lol. I'm building ego boxes for my band.

[Gray_Area]

Or just think about the last ten years of war news coverage and build a simple pressure plate like what is commonly found along the scenic roadways of the middle east.  Two metal plates with an insulated spring separating them. 

Those are designed for one-time use, though....

[JONTHEBOMB]

Seems to me you could browse a bunch of DIY DDR Pad builds and get a good take on what's doable.

http://blog.allthingsgeek.com/article/index/index/id/5/page/1#.UYnVzcrc92o

http://www.inventgeek.com/projects/dancepad1/OverView.aspx

Last year for my group senior design project (child hand eye coordination game) we created switches from DDR dance pad foam and Pure Copper Polyester Taffeta Fabric.  The switches were responsive and we never had issues with a stuck switch.  The video below shows the switches in action. 

[Howard_Casto]

It's super easy... take a thin metal plate....  cut some squares of 1/8th inch thick strip insulation (the stick on stuff you use for filling door frames and what not) and place them in a few locations on the plate, preferably the corners and one in the middle.  Now put another thin metal plate on top.  You are done....

Your weight will compress the insulation so that the plates touch.... attach your switch wires to each plate.  If you pull apart those cheap ddr matts, they all work on this principle.  (Although they usually use pieces of foil or something flexible.)

[ChadTower]

For a home made pad, though, you probably want something that will last longer than some foam.  Those pads become unreliable before long.  Some short metal springs from the hardware store will probably do the job.

[mpm32]

Some good ideas here, I'll try them and see how they work out.

[jmike]

I used something similar for a fight stick a while ago. Buttons lit up when you pressed them. (can't really remember what that was called  but I think I might still have one laying around the house somewhere) It was something like the Sparky SMD LED controller.
I'll take a look when I get home. Still had some pics of it on my desktop. 

[mpm32]

I figured it out.

The four corners of the plexi are screwed in.  I have a center bar running the length of the box under the plexi.

I drilled a recess for a spring so the center of the plexi gets supported.

I then put a microswitch with a lever on the side of the center bar so that when you step on the plexi, the switch gets depressed.

Works pretty well.  I'll take pics soon.

[ChadTower]

Heh.  He just pretty much described the construction of a pro wrestling ring.   

[Howard_Casto]

Heh.  He just pretty much described the construction of a pro wrestling ring.   

No, he didn't put a microphone underneath to make the bumps sound like they are killing each other. 

[mpm32]

I finished them. Since these pictures were taken I have painted them and the case hardware has been added.

There are three of them one is slightly smaller than the other two so it can nest in between them and be locked together for travel.  I'll have pictures of them in action after Friday's gig.