Today I took a hands-on class offered by the agency I work for called "Custom Switches". After our time with exact-o knives, wire cutters and strippers and soldering irons, we all left with two projects. The first was a String Switch (wherein you pull the string to make something happen) and the second a proximity switch (wherein you move a magnet (mounted to a glove, splint, head band, glasses arm, etc) in the vicinity of the switch to make something happen).
Here is a commercial string switch (retail $35.00, plus shipping) compared to mine (less than five dollars with shipping). Next to them both are the innards of my string switch.
And here are two commercial proximity switches next to my proximity switch. The first one pictured costs $55.00 and the second one costs $245.00; mine cost less than five dollars to build.
Most of the parts for these projects were purchased from All Electronics. Stay tuned for the results of the next class in the series where we will learn how to switch adapt computer mice and/or CD players (a week from Wednesday).
Note: My two switches will most likely not stand up to much abuse from my students, which is the dilemma - a custom switch for under five dollars you probably will need to make/buy again or one that will hold up a while longer (how much longer depends on the company you buy it from and how much abuse you give it).