That's true, but this is a sustained, audible oscillation. Add a momentary contact spst switch and you can practice morse code with it. It really is a neat little hack. =)
Simpler in terms of number of components, and type of components. Note: No semiconductors required. Also, I neglected to mention that you have to hook up the battery, speaker, and carbon mike in SERIES. =)
I discovered this little trick years ago by accident, but recently I read a passage in a little book called "Invention, The Care and Feeding of Ideas", by Norbert Weiner, that explained the phenomenon:
"... In short, the carbon microphone is a variable resistance that acts as a powerful amplifier... "
So, when you bring the carbon mike, a powerful amplifier, close to the speaker, which emits the amplified signal, you get feedback, i.e., oscillations.
One of the simplest and coolest hardware hacks of all time is hooking up a carbon microphone (like old-style telephone handsets had), a miniature speaker, and a 9 volt battery. point the speaker at the carbon mike and move it closer, voila! Instant oscillator. Probably the world's simplest electrical oscillator. And it shows how remarkably powerful an amplifier the carbon microphone is. (I believe the carbon microphone was invented by Thomas Edison.)
I think something like this was also tried at Arizona State University. Unfortunately, the ducks loved whatever they were using and would scoop the stuff up and get tipsy on it.
The book, _Life_With_Unix_, by Libes and Ressler, mentions a "Public-Domain Hardware" computer, a 32 bit system called the PD32. Does anyone know what happened to this project? I can't find any info about it on the net. Are/were there other projects like it? The PD32 was a 32 bit computer designed around the NSC32016 processor. But, why not an Public Domain or GPL processor itself?
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That's true, but this is a sustained, audible oscillation. Add a momentary contact spst switch and you can practice morse code with it. It really is a neat little hack. =)
Simpler in terms of number of components, and type of components. Note: No semiconductors required. Also, I neglected to mention that you have to hook up the battery, speaker, and carbon mike in SERIES. =) I discovered this little trick years ago by accident, but recently I read a passage in a little book called "Invention, The Care and Feeding of Ideas", by Norbert Weiner, that explained the phenomenon: "... In short, the carbon microphone is a variable resistance that acts as a powerful amplifier... " So, when you bring the carbon mike, a powerful amplifier, close to the speaker, which emits the amplified signal, you get feedback, i.e., oscillations.
One of the simplest and coolest hardware hacks of all time is hooking up a carbon microphone (like old-style telephone handsets had), a miniature speaker, and a 9 volt battery. point the speaker at the carbon mike and move it closer, voila! Instant oscillator. Probably the world's simplest electrical oscillator. And it shows how remarkably powerful an amplifier the carbon microphone is. (I believe the carbon microphone was invented by Thomas Edison.)
I liked "The Mote in God's Eye" better.
Great. This raises the specter of EMP. Hydrogen bombs exploded in near space that fry all of our semiconductor electronic devices. =/
Interesting... Frank Herbert also produced his own wines.
free memory tester here
This story is worthy of being posted again, I think.
I think something like this was also tried at Arizona State University. Unfortunately, the ducks loved whatever they were using and would scoop the stuff up and get tipsy on it.
Interesting. Aslan sang Narnia into existence.
A "hacker" is an "explorer of systems".
a "cracker" is a criminal.
Comprende?
man is the animal who laughs -- Robert Heinlein
a rocket a day keeps the shuttles away: a rocket a day
The book, _Life_With_Unix_, by Libes and Ressler, mentions a "Public-Domain Hardware" computer, a 32 bit system called the PD32. Does anyone know what happened to this project? I can't find any info about it on the net. Are/were there other projects like it? The PD32 was a 32 bit computer designed around the NSC32016 processor. But, why not an Public Domain or GPL processor itself?