Building Gadgets: How to Connect Momentary Switches & LEDs

  • Thread starter Pengwuino
  • Start date
  • Tags
    Build
In summary, the conversation is about making an IR pen for a project using a momentary switch that is low-profile and round, similar to the one seen in a Wii pen. The participants discuss using materials like beryllium copper or JB Weld to make the switch, and also mention scavenging a switch from another product or building one from scratch. They also suggest looking into classes at MIT for learning how to make gadgets, and mention the possibility of using an illuminated ball point pen as a base for the project. Lastly, someone suggests using conductive epoxy as a joke.
  • #1
Pengwuino
Gold Member
5,123
20
Yes, the subject sounds stupid but the question is even stupider!

ever since I was a kid I've liked building things, especially with electronics but I've never had any real education towards it etc etc no skills blah blah. Right now I want to build an IR pen for a project that was posted a while ago on the forum. The idea is to make a pen like:

http://johnnylee.net/projects/wii/pen.jpg

The problem is every momentary switch I see online, like http://www.sparkfun.com/commerce/product_info.php?products_id=8720" that is actually low-profile enough is build like a square, for lack of better terminology. The button is suppose to be in the pen so that you can press the button easily as if you were going to write with the pen. The button is square, the pen is hollow and round. How do you put this together? Also, the LED is smaller then the open end of the pen casing so I need to figure out how to make it fit more snug...

Where do I learn to make crazy cool gadgets!? I need some sort of ... metal... that's like playdough but its metal!
 
Last edited by a moderator:
Physics news on Phys.org
  • #2
a switch like that is just two pieces of metal and a spring. the spring could actually be one of the strips of metal. you just need materials with the right shape and characteristics. springy. corrosion-resistant. conductive. something like beryllium copper might be ideal, but brass maybe, or steel. just whatever you can salvage out of the broken electronics bin and can bend/cut/file/solder in place. mostly you just need imagination, tho.
 
  • #3
You could try scavenging a switch from some pre-existing product. I do that all the time. Or, you could simply build one. The easiest way would be to get a regular square housing microswitch that's smaller than the pen barrel and pad it to fit.
As for the material you want, I recommend JB Weld. It's a binary epoxy that you stir together and it becomes a semi-thick paste. When it hardens, it's as strong as steel. You can mend trailer hitches with it.
 
  • #4
I was thinking of some sort of non-conductive block of material that i could etch some paths for the current and glue that into the pen casing I have. Too bad I don't know how to etch... Then I could just cut away at the material so it fits into the pen haha
 
  • #5
i've actually got a cheap mechanical pencil here that has a button built into the side. the spring is in the tip where the LED would be located. you'd have to build a new spring under the button after removing the force-transfering mechanism and still leave room for the return wire to pass. but the battery would have to be smaller than even a AAA to fit in the eraser/lead cavity, even with the eraser holder stripped out. maybe look for something similar to alter, like... a penlight? ;)

https://www.pentelstore.com/index.php?grp=759
 
Last edited by a moderator:
  • #6
Your question "How do you build stuff?" reminded me of MIT's class, How to Make (Almost) Anything. I first came across this class when someone linked to this guy's http://fab.media.mit.edu/classes/MIT/863.08/people/ryan/week13.html" site and scroll down to their classes (the guy I linked to was in the '08 class). I thought you might be interested in it. I wish I could've taken part in a class like this. Super cool it is.
 
Last edited by a moderator:
  • #7
I'm not sure of what you want, but there is an illuminated ball point on the market somewhere (I have one, which I got from a neighbor). It has a button at the end which turns on and off a light in the barrel (possibly a LED). The writing point is extended and retracted by twisting the barrel. The light is in the upper part and projects down through the barrel which is transparent. This could probably be replaced with an opaque barrel which has an opening in the end. I don't know how to get one though.

KM
 
  • #8
Just use lots of glue... For electronics, that conductive epoxy! (just kidding)
 

Related to Building Gadgets: How to Connect Momentary Switches & LEDs

1. What is a momentary switch and how is it different from a regular switch?

A momentary switch is a type of switch that only makes contact for a brief period of time when it is pressed. This is different from a regular switch, which stays in the on or off position until it is manually changed.

2. How do I connect a momentary switch to an LED?

To connect a momentary switch to an LED, you will need to use a circuit that includes a resistor. The resistor will limit the amount of current that flows through the LED, preventing it from burning out. The switch will also need to be connected to the circuit in a way that allows it to control the flow of current to the LED.

3. How do I know which resistor to use when connecting a momentary switch to an LED?

The value of the resistor needed will depend on the voltage of your power source and the type of LED you are using. You can use an online resistor calculator or refer to a resistor color code chart to determine the correct value for your circuit.

4. Can I use multiple momentary switches to control one LED?

Yes, you can use multiple momentary switches to control one LED. This can be done by wiring the switches in parallel, so that pressing any one of them will complete the circuit and turn on the LED.

5. How can I make the LED stay on for a longer period of time when the momentary switch is pressed?

You can use a capacitor in your circuit to make the LED stay on for a longer period of time when the momentary switch is pressed. The capacitor will store energy and release it slowly, keeping the LED lit for a longer duration before it turns off again.

Similar threads

  • Electrical Engineering
Replies
6
Views
4K
Replies
6
Views
2K
Replies
4
Views
1K
Replies
6
Views
2K
Replies
16
Views
2K
  • Electrical Engineering
Replies
5
Views
4K
Replies
10
Views
2K
  • Electrical Engineering
Replies
4
Views
2K
Replies
42
Views
4K
Replies
5
Views
3K
Back
Top