Ear Buds

[Donald S. Lambert]

This concerns the ear plugs (ear buds) that some use to listen privately to various types of radios. For sake of simplicity I am referring to the monaural (single ear) type.<p>I have seen them listed as dynamic, crystal and ceramic and I presume that they are different. The dynamic I presume are the old style with an electromagnet to flex a magnetic diaphram to produce sound. I don't know what the crystal or ceramic types are.<p>My question is how does one tell which variety one has and what are the voltages that can be used to activate them?<p>Or are they universal enough that they all require the same voltages to function? Greybie

[haklesup]

Crystal or ceramic would refer to a piezo electric type of speaker. Probably not as good at the low end. Impedance of one of these speakers would be much higher and may have a cap or resistor in parallel to bring the impedance down.<p>Not all headphones are compatible but most made for music players are. Some like those used on airplanes have very high impedance so the volume is too low if you try using it for a regular music player. <p>High impedance headphones would also use less current and may result in longer battery life at the same volume setting (not necessarily the same volume <loudness> though)

[Mike]

I believe most are dynamic (like full size headphones or real speakers)

[CeaSaR]

Hacklesup pretty much whacks the iron fastener on the noggin. From everything I've read, the crystal types are pretty much relics from a bygone era. This doesn't mean you can't find them, but the standard dynamic type (think really small moving magnet speaker) are so ubiquitous that they have pretty much displaced the other types.<p>CeaSaR

[Donald S. Lambert]

I wish to apologize> I had a 4 or 5 way bypass operation back in Oct 2002 and to do the bypass the surgeon had to stop my heart. The 4 hour operation ended up exceeding 7 hrs. And since they tested me for memory loss because of that I do know that the few months preceeding the operation are spotting in memory retention. And this was one of them.<p>Back in July 28 2002 I posted a question subject earphones and there I had the answers that I wanted. Also in that time frame I bid on and won the bid for a 200 in one Radio Shack Electronics project lab. And I am currently starting to experiment with it. It came minus the ceramic earphone. I think searching for a replacement led to the posting on earphones.<p>I finally figured out how to search this forum with a subject search and pulled up this question along with other questions that had ear and phone in them.<p>I just wonder how many other readers know how to do a subject search. At the age of 79 I hope that there aren't too many that don't know. Sometimes you can get answers to questions without posting a question.<p>When I went to school a #2 pencil and yellow tablet was state of the art and high tech was a fountain pen and a bottle of ink. Greybie.

[Mike]

I'm glad you are OK!<p>That's OK, everybody forgets things they posted 3 years ago. I know I have! Recently, I looked through some of my old posts, and found ones I couldn't even remember, and I still couldn't remember them even after reading them again.

[Edd]

Sir Greybie:<p>“I wish to apologize> I had a 4 or 5 way bypass operation back in Oct 2002 and to do the bypass the surgeon had to stop my heart. The 4 hour operation ended up exceeding 7 hrs. And since they tested me for memory loss because of that I do know that the few months preceeding the operation are spotting in memory retention. And this was one of them.”<p>I for one , and Tony the Tiger, think that you are doing greeeeaaatttt, with taking such a operational licking and having your memory ticking along so well.<p>That indeed is a piezo type element that is used on those kits as well as some crystal sets.
Just drop an ohmmeter across it and note the very high or no resistance monitored.
Relevant in being used with xtal sets, and any minuscule low powered audio application, they really shine in their performance.
Back in the very early days when I was making crystal sets, I would always be using dynamic headphones that were a minimum of 2K impedance each and some of them I would rewind them with # 42 wire to get an ever higher z and sensitivity, along with a more compliant diaphragm design.
In the ‘50’s along came a small crystal set that was made in a case that was rocket shaped (red ?) and had an internal coil that was tuned via a sliding powdered iron core that was mechanically linked to a protruding brass rod. The very sensitive crystal earphone that they incorporated was what made that unit a real performer, along with the hi Q tuning elements and the fixed germanium detector diode.
http://www.bluesky.com/warren/radios/rocketradio
I don’t particularly see that RS has one of those xtal buds listed anymore, but there is a source south of me that caters to the crystal set experimenters. Actually, they are embellished quite a bit in their housings and construction. A very reasonable source of the mentioned xtal phone is available here:<p>http://www.ecrystalradio.com/parts.html <p>Side thought:
If you will think back to earlier cheeeep computers, they sometimes used a piezo speaker somewhat in the fabricated order of a basic Sonalert transducer. They typically had optimal acoustical resonance up in the 2kc spectrum but were functioning for “pseudo” audio response down into voice frequencies. If one were to take one of the elements and afford it the enhancement of an acoustical chamber surrounding it, one would expect there to be be somewhat of an improvement. The empty housing of a defunct conventional dynamic headphone could be used, shielding from ambient external noise, as well as keeping that element in close proximity to the ear, as compared to its prior open, external location.<p>73's de Edd
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<p>[ September 06, 2005: Message edited by: Edd Whatley ]</p>

[peter-f]

Hey there's a number of kits around now... and some come with 'supplemental' parts (Snap Circuits, fo one).<p>I bet calling the maker could get you some specs... or maybe a 'replacement'