OK, this may be a bad idea but.... This idea occured to me while I was trying to hide the fact I was wearing those little bud earphones (unfortunately they were bright green plastic). I had previously built a wireless loop induction pick up kit for operation with headphones in a cinema, and thought of applying the same principles to earphones. A necklace-like coil of copper wire would be worn around the neck, powered by a small amplifier (fed with a source, like a walkman) at something like half a watt (Did I just invent the neck-warming necklace?) Inside the eapieces, hidden inside the ear canal hearing-aid style, would be planted tiny coils, from which the amplified 'magnetic fluctuations' would be recieved, and hence turned into sound by the speaker. Sound complicated? I dont think it is, really. Just a thought on simple wireless headphones. I was advised *not* to try this, by a science teacher, should it adversely affect my brain...still, no ill effects from the cinemas.. yet >:)
So would it work? Would I experiece any ill side affects from a magnetic field *around my head*? Possibly an amp would be needed *inside* the earpiece. Possibly this has been discussed before. (I'm new to this place - my first post :):):)) I look forward to your feedback
And I want all royalties from this, by the way... :)-- ninety_percent_curious, Dec 31 2002 (?) For sale :)) http://www.geocitie.../examear/elite.html [KiralyVlad, Jan 29 2007] If you want royalties you should research prior art and take out a patent.
Transmitting signals by induction is basically "radio" in some form or another, and there are plenty of RF headphone kits. Most of them are external and wouldn't actually fit in your ear canal, though.
You seem to be suggesting that by emitting enough power with this necklace you would simplify the receiver circuitry and do away with the need for batteries. Maybe. Bear in mind that the induced current will be proportional to the area inside the coil; a big external induction loop will pick up a lot, but a little coil inside your ear won't.
Tell us more about the wireless loop induction pick up kit you built.-- egnor, Dec 31 2002 It was just a simple kit, used a couple hunded turns over a ferrite rod of about 2 cm (3/4" for you yanks?)in length. Worked fairly well, I remember playing round with earphones commected to just a coil suspended in the middle of a spool of wire, connected to the signal out-- ninety_percent_curious, Jan 03 2003 No, magnetic fields much stronger than what an electromagnet powered by house current cause no ill effects in humans, unless they have metallic implants.
Electromagnetic radiation at frequencies that might produce vibrations audible to humans are non-ionizing and thus cause no ill effects.
The only safety concerns I would have would be to avoid burns (which would be very hard to produce with half a watt of power) and excessive decibel levels in the earpiece.
Unfortunately, the AC power system operates at 60Hz, which I would expect to produce an audible hum in any equipment designed to directly convert EM fluctuations into sound. Not to mention lots of other electronic devices that I would expect to cause interference, and the interference that this device could cause in the proper operation of those devices.
Unless it were equipped with a directional antenna, it would expend a lot of power (relatively speaking, for a portable device) broadcasting in all directions, rather than just the one useful one.-- beland, Nov 05 2003 Certain agencies have used the induction loop and bud earpiece system on VHF/UHF two way radios for at least 10 years. the loop transmits very low power to the earpiece through the human body - very high quality signal is received with perfect clarity! a company called SONIC used to produce a earpiece and loop set compatable with most radios, but cant find them on the internet now......dunno if they have been taken over by someone else, but the earbud product code was LD4.-- deanocean, Aug 17 2004 They exist, I've tried one once, made by Nokia.
Take a look at this:
http://www. geocities .com/examear/elite.html
That necklace seems to be a common bluetooth earphone (look at the logo - Cellink, it's a company that produces mobile accesories), and they added the wire that acts like a RF transmitter.... I`m curios about the earbud though... I even found spy earphones like this on Ebay :))
I'm really interested in the bluetooth earphone modification....
Do you just solder the two ends of the cable in place of the built-in speaker ?!
Does the cable have to have a specific lenght ?
EDIT: Just found these links:
http://www. koss .com/koss/kossweb.nsf/ p?openform&pc^eb^PLUG
http://www. fixup .net/tips/earbud/ 30db_sealed_earphone.htm
What about taking off that plug, cuting off the wire, and rolling some wire on that rod, then put back the plug ? would that work?
Question: Why does that spy earplug need a battery ?!-- KiralyVlad, Jan 29 2007 random, halfbakery