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Steam and Electricity, Part 1: Electric Light

36 pointsby cfmcdonaldover 1 year ago

4 comments

Animatsover 1 year ago
Revisionist history of the incandescent lamp:<p>- 1840, first usable light bulb. Warren De la Rue enclosed a coiled platinum filament in a vacuum tube and passed an electric current through it. Worked fine. Platinum had a high enough melting point and could be drawn into wire, but was too expensive.<p>- 1840-1911 - era of crappy carbon filament light bulbs. Some fooling around with tantalum and osmium, but too expensive. Early tungsten work.<p>- 1906, William D. Coolidge at General Electric figures out how to make tungsten wire from tungsten powder. Finally, a cheap high-temperature (3410° C) wire. By 1911, GE is shipping tungsten-filament lamps. Same concept as de la Rue, but much cheaper. Tungsten filaments dominate incandescent bulbs thereafter.
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RetroTechieover 1 year ago
As someone who (in his careless youth) built a very crude arc lamp, a couple of findings:<p>1) Such lamps generate a good amount of UV radiation. So wear good UV-blocking eye protection! (discovered &#x27;cause I didn&#x27;t, in the first few runs).<p>2) Such lamps produce a good amount of ozone.<p>3) Some parts of the arc can indeed be very hot. Enough to melt pieces of glass, steel or even nickel.<p>4) What carbon rods are used matters a <i>lot</i> for how well it works. For example pencil leads had a tendency to &#x27;explode&#x27; along their full length. Not fun!<p>5) Confirmed: it&#x27;s a light source fascinating to look at.<p>FYI: I used carbon rods pulled from those big 6V batteries. &#x27;Socketed&#x27; in a base of lead. 220V AC with a 1..2kW electric heater in series as current limiter. Peak lighting power around [voltage over arc] = [voltage over series resistor] (so each taking ~110V in my case).<p>Don&#x27;t do this, kids. Just don&#x27;t. It&#x27;s really dangerous (although I survived long enough to write this post). We have YouTube now.
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MichaelRoover 1 year ago
When I was in high school, I lived in high school&#x27;s students hostel during the week. Bit of an army-like experience, for instance there were 8 beds in a room.<p>Anyhow, at some point someone (one of my colleagues) stole an industrial light bulb from I&#x27;ve no idea where and replaced our regular 100Watt bulb in the room. I&#x27;ve no idea what wattage it was but probably in the 500W - 1000Watt or something. It was an experience exactly like in Seinfeld&#x27;s &quot;Chicken Roaster&quot; episode: <a href="https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=q40fKsRsHFU" rel="nofollow">https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=q40fKsRsHFU</a><p>We closed the door so the warden won&#x27;t see us (I dunno the word, basically the fearsome guy that was in charge of controlling some 100 restless teenagers). But light would creep out though cracks like lasers, basically everyone noticed.<p>Anyhow (kinda stupid probably, good think we didn&#x27;t get lasting damage), we would stay in the &quot;laser&quot; room with eyelids shut and hands over them and gradually open them and remove the hands. Eventually we got used to the extreme light although it was clearly very bright. Then we&#x27;d exit the room to the normally lit corridor and ... stumble like blind people, effectively couldn&#x27;t see anything, it seemed completely dark.<p>The whole fun lasted some 10-15 minutes until the warden caught notice and came shouting blasphemies to confiscate the corpus delicti (stolen light bulb).
philipkglassover 1 year ago
The earliest electrical power suppliers frequently had complex and varying prices according to different <i>applications</i> for electricity. See this 1903 document from the National Electric Light Association, &quot;Report of the rates for lighting and power service.&quot;<p><a href="https:&#x2F;&#x2F;babel.hathitrust.org&#x2F;cgi&#x2F;pt?id=nnc1.cu56609884&amp;seq=11" rel="nofollow">https:&#x2F;&#x2F;babel.hathitrust.org&#x2F;cgi&#x2F;pt?id=nnc1.cu56609884&amp;seq=1...</a><p>In San Francisco, there were separate rates per kilowatt hour depending on whether the electricity was used for incandescent lighting or &quot;power.&quot; San Leandro had 3 separate rate structures -- one for incandescent lighting, one for arc lighting, and a third for power.<p>Eventually, of course, device manufacturers realized that it was possible to tap &quot;power&quot; connections to run &quot;lighting&quot; devices, or vice versa, and the application-specific pricing could not be maintained.
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