On Sat, Nov 19, 2022 at 01:18 PM, Jeff Green wrote:
You can use those as described in:
?
Fascinating. Spent about an hour going through the articles and especially the ads. Wow, TVs ranged from $99 kit ($1,200 in todays dollars) to some kind of small rear projection TV that would cost around $12,000 in today's money. No wonder very few people had TVs back then.
But in one way we have really gone backwards in technology. In 1948 you could buy a radio to install in your automobile, that not only could charge your car's battery, but could
power your electric shaver.
Where are radios like that today. And to think that could do that way Bach in 1948. What is holding this technology back?
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By the way I recently read an article, and have tried it out, in reproducing the first LED discovered around 1912.?
Take a chunk of silicon carbide, wrap a wire around it and hook it to a power supply positive terminal. Put a small wire or nail on the Negative lead, probe around and you will see spots where the crystal will glow. It is an actual semiconductor junction converting electrons to photons; not heat.?
My experiment required around 24 VDC (Three 9v batteries work great) at around 50 MA to light up. I used a small 24 volt incandescent lamp as a safety current limiter. But, really cool. Some the the crystal formations glow on the edge, giving a asteroid space ship window effect.?
Fortunately the efficiency of purpose made LEDs has become a lot higher than the accident of nature LED junctions in a silicon carbide crystal.
Tom, wb6b
