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#1
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Take apart a couple of D cell carbon-zinc batteries.
Wash off the carbon rods. Put each in a wooden clothes pin and connect the attached ends to the mains voltage (US customers only, please). Tap the free ends of the rods together. Move them apart as necessary. Very bright! Much brighter than you are. Jon |
#2
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On Thu, 24 Nov 2005 18:49:24 -0500, Jon Yaeger wrote:
Take apart a couple of D cell carbon-zinc batteries. Wash off the carbon rods. Put each in a wooden clothes pin and connect the attached ends to the mains voltage (US customers only, please). Tap the free ends of the rods together. Move them apart as necessary. Very bright! Much brighter than you are. One of the MIT EE course videos on the web shows a demonstration of AC across a pickle... it is an interesting effect. Not sure how the pickle tastes afterward. Cooking hotdogs with AC is similar, but the pickle gives off a much nicer translucent flickering glow. Very pretty. --- Regards, Bob Monsen The question of the ultimate foundations and the ultimate meaning of mathematics remains open; we do not know in what direction it will find its final solution or even whether a final objective answer can be expected at all. "Mathematizing" may well be a creative activity of man, like language or music, of primary originality, whose historical decisions defy complete objective rationalization. - Hermann Weyl in 1944 |
#3
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On Fri, 25 Nov 2005 00:43:52 -0800, Bob Monsen wrote:
On Thu, 24 Nov 2005 18:49:24 -0500, Jon Yaeger wrote: Take apart a couple of D cell carbon-zinc batteries. Wash off the carbon rods. Put each in a wooden clothes pin and connect the attached ends to the mains voltage (US customers only, please). Tap the free ends of the rods together. Move them apart as necessary. Very bright! Much brighter than you are. One of the MIT EE course videos on the web shows a demonstration of AC across a pickle... it is an interesting effect. Not sure how the pickle tastes afterward. Cooking hotdogs with AC is similar, but the pickle gives off a much nicer translucent flickering glow. Very pretty. But who wants a cooked pickle? ;-) Thanks, Rich |
#4
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Rich Grise wrote:
... But who wants a cooked pickle? ;-) My ethnic Russian daughter-in-law, just arrived from Tatarstan, made a Russian soup, into which she chopped several dill pickles. Wonderful stuff! John Perry |
#5
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On Thu, 24 Nov 2005 18:49:24 -0500, Jon Yaeger
wrote: Take apart a couple of D cell carbon-zinc batteries. Wash off the carbon rods. Put each in a wooden clothes pin and connect the attached ends to the mains voltage (US customers only, please). The problem is that the carbon rod conducts heat quite well, so after a while, any wooden object will catch fire :-). Tap the free ends of the rods together. Move them apart as necessary. You must have quite slow fuses in 110 V land if you can do a reliable ignition without blowing the fuse. For 230 V operation, I would suggest using a current limiting resistor (such as a large heater) or an inductance (such as fluorescent light ballast) during the ignition. When there is a solid arc, the current limiter can be shorted out. Paul |
#6
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Paul Keinanen wrote:
. . . You must have quite slow fuses in 110 V land if you can do a reliable ignition without blowing the fuse. For 230 V operation, I would suggest using a current limiting resistor (such as a large heater) or an inductance (such as fluorescent light ballast) during the ignition. When there is a solid arc, the current limiter can be shorted out. Aren't you in danger of damaging your eyes from the UV emitted from the arc? Roy Lewallen, W7EL |
#7
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On Fri, 25 Nov 2005 12:29:52 -0800, Roy Lewallen
wrote: Paul Keinanen wrote: . . . You must have quite slow fuses in 110 V land if you can do a reliable ignition without blowing the fuse. For 230 V operation, I would suggest using a current limiting resistor (such as a large heater) or an inductance (such as fluorescent light ballast) during the ignition. When there is a solid arc, the current limiter can be shorted out. Aren't you in danger of damaging your eyes from the UV emitted from the arc? Certainly. I used arc welding glasses when conducing these experiments. Some trivia: In the silent film era, actors had eye problems due to the UV radiation from arc studio lamps. Most of the usable illumination from the arc lights is actually from the glowing carbon electrodes. "Automatic arc lights" used a solenoid in series with the arc to keep the distance constant between the poles regardless of carbon electrode burnout. I assume that if this is to be used with a AC arc light, both the moving coil as well as the static coil should carry the arc current. Paul OH3LWR |
#8
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In article ,
Paul Keinanen wrote: On Thu, 24 Nov 2005 18:49:24 -0500, Jon Yaeger wrote: Take apart a couple of D cell carbon-zinc batteries. Wash off the carbon rods. Put each in a wooden clothes pin and connect the attached ends to the mains voltage (US customers only, please). The problem is that the carbon rod conducts heat quite well, so after a while, any wooden object will catch fire :-). Tap the free ends of the rods together. Move them apart as necessary. You must have quite slow fuses in 110 V land if you can do a reliable ignition without blowing the fuse. For 230 V operation, I would suggest using a current limiting resistor (such as a large heater) or an inductance (such as fluorescent light ballast) during the ignition. When there is a solid arc, the current limiter can be shorted out. Paul I would put a 100 watt lamp in series thereby limiting the current. I would shave the ends down to points so they heated up rapidly. I put them into a hollowed out fire brick and made a cheap furnace. Of course don't look at it; it's like looking at the sun. PS: I was 16 at the time ;-) |
#9
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On Fri, 25 Nov 2005 20:48:19 GMT, Al wrote:
In article , Paul Keinanen wrote: On Thu, 24 Nov 2005 18:49:24 -0500, Jon Yaeger wrote: Take apart a couple of D cell carbon-zinc batteries. Wash off the carbon rods. Put each in a wooden clothes pin and connect the attached ends to the mains voltage (US customers only, please). The problem is that the carbon rod conducts heat quite well, so after a while, any wooden object will catch fire :-). Tap the free ends of the rods together. Move them apart as necessary. You must have quite slow fuses in 110 V land if you can do a reliable ignition without blowing the fuse. For 230 V operation, I would suggest using a current limiting resistor (such as a large heater) or an inductance (such as fluorescent light ballast) during the ignition. When there is a solid arc, the current limiter can be shorted out. Paul I would put a 100 watt lamp in series thereby limiting the current. I would shave the ends down to points so they heated up rapidly. I put them into a hollowed out fire brick and made a cheap furnace. Of course don't look at it; it's like looking at the sun. The current limiter I saw used a glass pie pan with pieces copper metal on each side with salty water as the electrolyte. It would start to steam some when in operation. The furnace was a small clay flower pot with holes in each side with the carbon rods sticking inside until they touched. |
#10
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In article ,
Al wrote: In article , Paul Keinanen wrote: On Thu, 24 Nov 2005 18:49:24 -0500, Jon Yaeger wrote: Take apart a couple of D cell carbon-zinc batteries. Wash off the carbon rods. Put each in a wooden clothes pin and connect the attached ends to the mains voltage (US customers only, please). The problem is that the carbon rod conducts heat quite well, so after a while, any wooden object will catch fire :-). Tap the free ends of the rods together. Move them apart as necessary. You must have quite slow fuses in 110 V land if you can do a reliable ignition without blowing the fuse. For 230 V operation, I would suggest using a current limiting resistor (such as a large heater) or an inductance (such as fluorescent light ballast) during the ignition. When there is a solid arc, the current limiter can be shorted out. Paul I would put a 100 watt lamp in series thereby limiting the current. I would shave the ends down to points so they heated up rapidly. I put them into a hollowed out fire brick and made a cheap furnace. Of course don't look at it; it's like looking at the sun. PS: I was 16 at the time ;-) I used a 0.5 or 0.7 mm pencil lead gently torqued down across the terminals of a regulated DC power supply. Set the current limit very low, crank the voltage up all the way and increase the current limit until the center of the lead starts glowing red. Due to the heatsinking effect of the binding posts, the lead will always heat up the most in the center, then the carbon will start to evaporate and the remaining lead will gradually neck down in the center until it is glowing white hot. As soon as the lead breaks in the middle, you convert from incandescent to carbon arc lamp, which usually surprises everybody watching. The arc is good for about 5 seconds until the voltage drop across the arc exceeds the capability of the power supply. |
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